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Bibliography on: Telomeres

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ESP: PubMed Auto Bibliography 03 Dec 2024 at 01:59 Created: 

Telomeres

Wikipedia: A telomere is a region of repetitive nucleotide sequences at each end of a chromosome, which protects the end of the chromosome from deterioration or from fusion with neighboring chromosomes. Its name is derived from the Greek nouns telos (τέλος) "end" and merοs (μέρος, root: μερ-) "part". For vertebrates, the sequence of nucleotides in telomeres is TTAGGG, with the complementary DNA strand being AATCCC, with a single-stranded TTAGGG overhang. This sequence of TTAGGG is repeated approximately 2,500 times in humans. In humans, average telomere length declines from about 11 kilobases at birth to less than 4 kilobases in old age,[3] with average rate of decline being greater in men than in women. During chromosome replication, the enzymes that duplicate DNA cannot continue their duplication all the way to the end of a chromosome, so in each duplication the end of the chromosome is shortened (this is because the synthesis of Okazaki fragments requires RNA primers attaching ahead on the lagging strand). The telomeres are disposable buffers at the ends of chromosomes which are truncated during cell division; their presence protects the genes before them on the chromosome from being truncated instead. The telomeres themselves are protected by a complex of shelterin proteins, as well as by the RNA that telomeric DNA encodes.

Created with PubMed® Query: telomere.q.txt NOT pmcbook NOT ispreviousversion

Citations The Papers (from PubMed®)

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RevDate: 2024-12-02

Sumesh D, Lin J, JM Wojcicki (2024)

High school diploma is associated with longer postpartum leukocyte telomere length in a cohort of primarily Latina women.

Maternal health, neonatology and perinatology, 10(1):25.

OBJECTIVE: This study investigates correlates of maternal leukocyte telomere length (LTL) in the immediate postpartum period using a cross-sectional study design from an existing prospective longitudinal birth cohort of primarily Latina women. The study focuses on the role of maternal health and dietary habits in pregnancy and maternal education level and LTL at delivery.

STUDY DESIGN: Latina mothers were recruited during the immediate postpartum period prior to 24 h at two San Francisco hospitals and dried blood spots were collected for LTL analysis via quantitative polymerase chain reaction (qPCR). We used multivariable linear regression models to determine independent predictors of maternal LTL during the postpartum period.

RESULTS: In multivariable regression models, increasing maternal age was associated with shorter LTL during the immediate postpartum period (Coeff - 0.015; p < 0.01) whereas having a high school diploma was associated with longer LTL versus not having graduated from high school (Coeff 0.12; p < 0.01).

CONCLUSION: Maternal education level as a potential marker of exposure to life stressors and socioeconomic status was associated with maternal LTL after adjusting for age and other potential confounders in women of reproductive age.

RevDate: 2024-12-02

Chen J, Liu H, Pang Y, et al (2024)

Genetic Association of Chronic Pains and Analgesics With Telomere Length: A Mendelian Randomization Study.

Biological research for nursing [Epub ahead of print].

Objective: The aim of this study was to explore the causal relationships between chronic pains (back pain, facial pain, general pain, headaches, knee pain, hip pain, neck/shoulder pain, stomach/abdominal pain) and analgesics (codeine, diclofenac, ibuprofen, morphine, paracetamol, tramadol) with telomere length using Mendelian randomization methods. Methods: In the study, various statistical methods including inverse variance weighted (IVW), Mendelian Randomization-Egger, weighted median, simple mode, and weighted mode were used to investigate the relationships between chronic pains, analgesics, and telomere length. Heterogeneity and pleiotropy tests were conducted to ensure the accuracy of the results. Results: The results of the IVW analysis revealed positive causal relationships between hip pain (odds ratio (OR): 1.145; 95% confidence interval (CI): 1.021-1.285; p = .020), and stomach/abdominal pain (OR: 1.100; 95% CI: 1.008-1.200; p = 0.033) with telomere length. Use of tramadol (OR: 0.074; 95% CI: 0.009-0.605; p = 0.015) had a negative causal relationships with telomere length. Conclusion: This study found positive associations between hip pain and stomach/abdominal pain with telomere length, and a negative association between tramadol and telomere length. However, no significant causal relationships were found with other types of chronic pains and analgesics. This could help develop healthier chronic pain treatments, avoiding the abuse of analgesics.

RevDate: 2024-11-30

Kvarnung M, Pettersson M, Chun-On P, et al (2024)

Identification of biallelic POLA2 variants in two families with an autosomal recessive telomere biology disorder.

European journal of human genetics : EJHG [Epub ahead of print].

POLA2 encodes the accessory subunit of DNA polymerase α (polα)/primase, which is crucial for telomere C-strand fill-in. Incomplete fill-in of the C-rich telomeric strand after DNA replication has been proposed as a mechanism for Coats plus syndrome, a phenotype within the broader spectrum of telomere biology disorders (TBD). Coats plus syndrome has so far been associated with pathogenic variants in POT1, CTC1, and STN1. Here we report the findings of biallelic deleterious rare variants in POLA2 gene detected by whole genome sequencing and segregation analysis in five young adults from two unrelated families. All five individuals displayed abnormally short telomeres and a clinical phenotype suggesting a TBD disorder with Coats plus features including retinal and gastrointestinal telangiectasias. Our results suggest POLA2 as a novel autosomal recessive gene for a TBD with Coats plus features.

RevDate: 2024-11-30

Modi P, Pennington K, Shah S, et al (2024)

Clinical Outcomes of Lung Transplant Recipients with Myelodysplastic Syndrome and Short Telomere Syndrome-Case Series.

Transplantation proceedings pii:S0041-1345(24)00567-0 [Epub ahead of print].

Limited data exists concerning the postlung transplantation outcomes of patients diagnosed with myelodysplastic syndrome (MDS). We delineate the clinical trajectories and outcomes for 3 patients with MDS and Short Telomere Syndrome (STS) who underwent lung transplantation. Our findings suggest that patients with STS and low-risk MDS, especially those harboring the SF3B1 mutation, tolerated standard immunosuppression and antimicrobial prophylaxis well without significant deviation from a typical post-transplant course. Therefore, individuals with low-risk MDS should not be automatically excluded from lung transplantation consideration. Post-transplant monitoring is crucial to promptly detect and manage cytopenias. Conversely, our patient, diagnosed with high-risk MDS post-transplantation faced a poor prognosis, with severe cytopenias limiting immunosuppression treatment and resulting in rejection. Thus, abundance of caution is warranted when contemplating lung transplantation for individuals with high-risk MDS and STS. Further research is necessary to validate these findings.

RevDate: 2024-11-30

Tilekli MM, Yılmaz AK, Yasul Y, et al (2024)

Influence of diet and exercise on leukocyte telomere length, markers of oxidative stress and inflammation in rats.

Experimental and molecular pathology, 140:104947 pii:S0014-4800(24)00067-4 [Epub ahead of print].

Telomere length is an important biomarker of biological aging and is affected by nutrition and physical activity. This study investigated the effects of diets with different fat contents and increased physical activity on certain pro/anti-inflammatory and oxidative stress markers and aging. The study is performed in a randomized, experimental, and controlled design with 48 rats, 8 weeks old, divided into 6 different groups (Control (C), exercise (E), unsaturated fat diet (USF), saturated fat diet (SF), unsaturated fat diet + exercise (USF + E), and saturated fat diet + exercise (SF + E)). The rats performed aerobic swimming exercise for 50 days and were fed a diet with different fat content. TAS, TOS, and MDA levels were determined by colorimetric analysis while 8-OHdG, IL-10, and TNF-α were determined by ELISA. Additionally, leukocyte telomere length is determined by the PCR method. Weight changes were also recorded. Plasma TOS, OSI, and TNF-α were lowest in the USF group and highest in the SF and SF + E groups. MDA, 8-OHdG and TG levels were highest in the SF group. The lowest IL-10 level was detected in group C. TL level was the highest in the USF group. There was also a moderate, negative, and significant correlation between telomeres and TOS, OSI, and TNF-α. The groups with the highest body weight gain were C, SF, and SF + E. Diets low in saturated fat or high in unsaturated fat, and physical activity were associated with leukocyte telomere length and alteration of oxidative and pro/anti-inflammatory markers.

RevDate: 2024-11-30

Taseva T, Koycheva Y, Racheva R, et al (2024)

Altered Mitochondrial DNA Copy Number and Telomere Length in Patients with Substance Use Disorder: Correlation with Age, Sex, and Chronic Diseases.

Biochemical genetics [Epub ahead of print].

Substance use disorder (SUD) is a complex condition involving psychological, sociocultural, and genetic factors. In this study, we examined the alternations in mitochondrial DNA copy number (mtDNAcn) and telomere length (TL) and their relationship to demographic, medical, heredity, and substance use characteristics in patients with SUD and healthy controls. We investigated a total cohort of 54 participants: 21 healthy individuals, 17 patients with alcohol dependence (AD), and 16 patients with drug dependence (DD). TL and mtDNAcn were measured using quantitative real-time PCR, with statistical methods used to assess the association between variables. We observed a significant decrease in mtDNAcn in both SUD groups, particularly associated with chronic diseases in the AD group. No significant differences in TL were found among the three groups. Sex-associated analysis revealed a significant mtDNAcn reduction in the DD males and elevated TL in AD males compared to control males. Correlation analyses showed associations between the two biomarkers and age, sex, and chronic diseases. Our findings suggest that leukocyte mtDNAcn is a more sensitive marker than TL in patients with SUD, indicating sex-specific patterns of alterations. These findings require confirmation through larger cohort recruitment.

RevDate: 2024-11-29

Jones-Weinert C, Mainz L, J Karlseder (2024)

Telomere function and regulation from mouse models to human ageing and disease.

Nature reviews. Molecular cell biology [Epub ahead of print].

Telomeres protect the ends of chromosomes but shorten following cell division in the absence of telomerase activity. When telomeres become critically short or damaged, a DNA damage response is activated. Telomeres then become dysfunctional and trigger cellular senescence or death. Telomere shortening occurs with ageing and may contribute to associated maladies such as infertility, neurodegeneration, cancer, lung dysfunction and haematopoiesis disorders. Telomere dysfunction (sometimes without shortening) is associated with various diseases, known as telomere biology disorders (also known as telomeropathies). Telomere biology disorders include dyskeratosis congenita, Høyeraal-Hreidarsson syndrome, Coats plus syndrome and Revesz syndrome. Although mouse models have been invaluable in advancing telomere research, full recapitulation of human telomere-related diseases in mice has been challenging, owing to key differences between the species. In this Review, we discuss telomere protection, maintenance and damage. We highlight the differences between human and mouse telomere biology that may contribute to discrepancies between human diseases and mouse models. Finally, we discuss recent efforts to generate new 'humanized' mouse models to better model human telomere biology. A better understanding of the limitations of mouse telomere models will pave the road for more human-like models and further our understanding of telomere biology disorders, which will contribute towards the development of new therapies.

RevDate: 2024-11-29

Liu Q, Fan G, Bi J, et al (2024)

Exposure to multiple metals and leukocyte telomere length in children and adolescents: The mediating effect of thyroid hormones.

Environmental research pii:S0013-9351(24)02390-9 [Epub ahead of print].

Exposure to metals has been related to alterations in leukocyte telomere length (LTL), an aging marker. However, the evidence regarding this relationship in children and adolescents, as well as the underlying mechanisms, remains unclear. Therefore, we aimed to explore the individual and mixture effects of metals on LTL in children and adolescents and to assess the mediating role of thyroid hormones and the modifying effect of a healthy lifestyle. In a cross-sectional study performed in Liuzhou, China, we assessed 5 serum thyroid hormones, 18 urinary metals, and LTL among 1050 children and adolescents aged 6-18 years. We employed multivariate linear regression and weighted quantile sum (WQS) regression to assess the associations of urinary metals with LTL in children and adolescents. Mediation analyses were conducted to explore the effects of thyroid hormones on these relationships. Urinary cobalt (Co), nickel (Ni), strontium (Sr), mercury (Hg), cadmium (Cd), and thallium (Tl) were related to a shorter LTL in children and adolescents. The WQS regression showed a 6.31% (95% CI: -8.76%, -3.79%) decrease in LTL per quartile increase in the WQS index, and identified Ni (23.3%), Sr (21.7%), and Tl (18.0%) as the major contributors. Mediation analyses showed that triiodothyronine (T3) mediated 14.8% and 8.1% of the associations of urinary Sr and Hg with LTL, respectively, and suppressed 9.3% of the association with urinary Co. Furthermore, the inverse associations of Sr, Cd, and Tl with LTL were attenuated among participants who adopted a healthy lifestyle. Our findings suggested that exposure to Co, Ni, Sr, Cd, Hg, Tl, and their mixture were related to a shorter LTL in children and adolescents, potentially mediated by thyroid hormones. Additionally, adopting a healthy lifestyle may alleviate these adverse effects.

RevDate: 2024-11-28

Fang H, Wu J, Xie L, et al (2024)

Telomere-to-telomere genome assembly of eggplant (Solanum melongena L.) promotes gene fine localization of the green stripe (GS) in pericarp.

International journal of biological macromolecules pii:S0141-8130(24)08905-0 [Epub ahead of print].

Fruit appearance of eggplant is a key commercial trait, and the precise selection of new varieties with diverse aesthetics aligns with current breeding objectives. However, functional genomics research in eggplant remains underdeveloped. Here, we assembled the first telomere-to-telomere (T2T) eggplant genome, as well as chloroplast and mitochondrial genomes for the inbred line 'NO211'. The 1.06-Gb SmT2T genome is anchored to 12 chromosomes, nine of which are gap-free, totaling three gaps. This assembly harbors 36,505 genes and 64.08 % repetitive sequences, identifying 12 centromeres and 22 telomeres. Utilizing the SmT2T genome for bulked segregant analysis (BSA) and forward genetic approach with green-striped 'NO211' and pure green 'P13' as parents, the green stripe (GS) locus was finely mapped to a 9-Kb region on Chr4, containing a single gene, eggplant.04G07850 (GLK protein). Sequence analysis and qRT-PCR revealed that a single-base deletion in the exon of SmGLK in 'P13' led to premature stop codon, and SmGLK expression was significantly higher in the pericarp of 'NO211' compared to 'P13'. A marker was developed and validated in 36 germplasms, demonstrating co-segregation with green-striped rind trait. This study provides an ideal reference genome for eggplant functional genomics studies, facilitating mechanistic research on peel stripe formation and molecular-assisted selection for fruit appearance.

RevDate: 2024-11-28

Tan MY, Zhang P, M Gao (2024)

Letter to the editor - "Association of healthy and unhealthy plant-based diets with telomere length".

RevDate: 2024-11-28

Lin SY, Futeran H, MT Levine (2024)

Adaptive protein coevolution preserves telomere integrity.

bioRxiv : the preprint server for biology pii:2024.11.11.623029.

Many essential conserved functions depend, paradoxically, on proteins that evolve rapidly under positive selection. How such adaptively evolving proteins promote biological innovation while preserving conserved, essential functions remains unclear. Here, we experimentally test the hypothesis that adaptive protein-protein coevolution within an essential multi-protein complex mitigates the deleterious incidental byproducts of innovation under pressure from selfish genetic elements. We swapped a single, adaptively evolving subunit of a telomere protection complex from Drosophila yakuba into its close relative, D. melanogaster . The heterologous subunit uncovered a catastrophic interspecies incompatibility that caused lethal telomere fusions. Restoring six adaptively evolving sites on the protein-protein interaction surface, or introducing the D. yakuba interaction partner, rescued telomere integrity and viability. Our in vivo , evolution-guided manipulations illuminate how adaptive protein-protein coevolution preserves essential functions threatened by an evolutionary pressure to innovate.

RevDate: 2024-11-27

Teng Y, Gao Y, Liu L, et al (2024)

Sex differential effects of early maternal separation on PTSD susceptibility in adult rats accompanied by telomere shortening in the hippocampus.

Neuroscience pii:S0306-4522(24)00647-X [Epub ahead of print].

Early life stress (ELS) is thought to be a leading cause of mental disorders in adulthood, including PTSD. Recent studies have found that such stress has a gender and resilient specific effect on adult PTSD. This study aimed to assess emotion, and cognitive behavior, and to examine the sex differences and resilience of ELS on adult PTSD. At the same time, the expression of hippocampal telomere length and telomere repeat binding factors (TRF1 and TRF2) were detected to explore the mechanism of telomere length change. Rat offspring were separated from their dams (3 h/day or 6 h/day from PND2 ∼ PND14). Then, pups were treated with a single prolonged stress (SPS) procedure when they reached adulthood (PND80). Rats exposed early to MS and SPS showed anxiety-like and depression-like behaviors as well as impaired learning and memory. The rats exposed to MS3h showed reduced anxiety-like and depression-like behavior upon re-experiencing "secondary stress" compared to the SPS and MS6h groups. Behavioral results showed no significant gender difference. However, gender and SPS factors significantly affected telomere length and TRF1 and TRF2 gene expression in hippocampus. The SPS effect and MS*SPS interaction significantly impacted TRF1 and TRF2 protein expression. In conclusion, this study shows that MS has different effects on anxiety, depression, and cognitive memory deficits in rats experiencing "secondary stress" in adulthood and is accompanied by telomere shortening in the hippocampus. This reveals the potential impact of early MS on PTSD and provides a new perspective for further research in the field of psychological stress.

RevDate: 2024-11-27

Li X, Li M, Cheng J, et al (2024)

"Reply - Letter to the editor" - "Association of healthy and unhealthy plant-based diets with telomere length".

RevDate: 2024-11-27

Tucker LA, CJ Bates (2024)

Telomere Length and Biological Aging: The Role of Strength Training in 4814 US Men and Women.

Biology, 13(11): pii:biology13110883.

Telomere length is an index of cellular aging. Healthy lifestyles are associated with reduced oxidative stress and longer telomeres, whereas unhealthy behaviors are related to shorter telomeres and greater biological aging. This investigation was designed to determine if strength training accounted for differences in telomere length in a random sample of 4814 US adults. Data from the National Health and Nutrition Examination Survey (NHANES) were employed to answer the research questions using a cross-sectional design. Time spent strength training was calculated by multiplying days of strength training per week by minutes per session. Participation in other forms of physical activity was also calculated based on reported involvement in 47 other activities. Weighted multiple regression and partial correlation were used to calculate the mean differences in telomere length across levels of strength training, adjusting for differences in potential confounders. With the demographic covariates controlled, strength training and telomere length were linearly related (F = 14.7, p = 0.0006). Likewise, after adjusting for all the covariates, the linear association remained strong and significant (F = 14.7, p = 0.0006). In this national sample, 90 min per week of strength training was associated with 3.9 years less biological aging, on average. Regular strength training was strongly related to longer telomeres and less biological aging in 4814 US adults.

RevDate: 2024-11-27
CmpDate: 2024-11-27

Zhao L, Li Z, Jiang S, et al (2024)

The Telomere-to-Telomere Genome of Jaboticaba Reveals the Genetic Basis of Fruit Color and Citric Acid Content.

International journal of molecular sciences, 25(22): pii:ijms252211951.

Jaboticaba is a typical tropical plant that blossoms and bears fruit on the tree trunks and branches. The fruits resemble grapes in appearance and texture and are also known as "treegrapes". Currently, research on the genomics of jaboticaba is lacking. In this study, we constructed an integrated, telomere-to-telomere (T2T) gap-free reference genome and two nearly complete haploid genomes, thereby providing a high-quality genomic resource. Furthermore, we unveiled the evolutionary history of several species within the Myrtaceae family, highlighting significant expansions in metabolic pathways such as the citric acid cycle, glycolysis/gluconeogenesis, and phenylpropanoid biosynthesis throughout their evolutionary process. Transcriptome analysis of jaboticaba fruits of different colors revealed that the development of fruit skin color in jaboticaba is associated with the phenylpropanoid and flavonoid biosynthesis pathways, with the flavanone 3-hydroxylase (F3H) gene potentially regulating fruit skin color. Additionally, by constructing the regulatory pathway of the citric acid cycle, we found that low citric acid content is correlated with high expression levels of genes such as thiamin diphosphate (ThDP) and low expression of phosphoenolpyruvate carboxykinase (PEPCK), indicating that PEPCK positively regulates citric acid content. These T2T genomic resources will accelerate jaboticaba pepper genetic improvement and help to understand jaboticaba genome evolution.

RevDate: 2024-11-27

Lv J, Zhao X, Zhao L, et al (2024)

The Notable Role of Telomere Length Maintenance in Complex Diseases.

Biomedicines, 12(11):.

Telomere length function serves as a critical biomarker for biological aging and overall health. Its maintenance is linked to cancer, neurodegenerative conditions, and reproductive health. This review mainly examines genetic variations and environmental influences on telomere dynamics, highlighting key regulatory genes and mechanisms. Advances in telomere measurement methodologies are also reviewed, underscoring the importance of precise telomere assessment for disease prevention and treatment. Telomerase activation offers potential for cellular lifespan extension and anti-aging effects, whereas its inhibition emerges as a promising therapeutic approach for cancer. Regulatory mechanisms of tumor suppressor genes on telomerase activity are analyzed, with a comprehensive overview of the current state and future potential of telomerase inhibitors. In addition, the association between telomeres and neurodegenerative diseases is discussed, detailing how telomere attrition heightens disease risk and outlining multiple pathways by which telomerase protects neurons from damage and apoptosis.

RevDate: 2024-11-26

Jiang Y, Xu Z, Wang M, et al (2024)

Association Between Prenatal Exposure to Organochlorine Pesticides and Telomere Length in Neonatal Cord Blood.

Toxics, 12(11): pii:toxics12110769.

Objectives: Environmental exposure may affect the telomere length (TL) of newborns, which is considered as an early biomarker indicating susceptibility for later life diseases. However, the effects of prenatal organochlorine pesticide (OCP) exposure on newborn TL remain unclear. This study aimed to investigate the association between prenatal exposure levels of OCPs during pregnancy and TL in neonatal cord blood. Methods: A total of 168 mother-infant pairs from a birth cohort in Wuhan, China, were included this study. The concentrations of hexachlorocyclohexanes (HCHs, including β-HCH, α-HCH, and γ-HCH), p,p'-dichlorodiphenyltrichloroethane (p,p'-DDT) and its metabolites (p,p'-dichlorodiphenyldichloroethane, p,p'-DDD; p,p'-dichlorodiphenyldichloroethylene, p,p'-DDE) were measured in cord blood. The associations between the OCPs and the TL in newborns were analyzed by a generalized linear regression model. Stratified analyses by newborn sex, maternal gestational weight gain, and pregnancy body mass index (BMI) were performed to evaluate if the associations were modified by these factors. Results: The detection rates of various OCPs ranged from 50.9% to 100.0%. The median concentration of p,p'-DDE was the highest (33.90 ng/g lipid), followed by β-HCH (8.67 ng/g lipid), and the median concentrations of the other OCPs were between 0.12 and 0.33 ng/g lipid. Among the all newborns, a two-fold increase in the γ-HCH concentration in the cord blood was significantly associated with a 0.024 (95% CI: -0.041, -0.007) decrease in the TL. After stratification by newborn sex, the inverse association between γ-HCH and the TL was only statistically significant in boys, but not in girls (P for interaction <0.05). In addition, after stratification by pre-pregnancy BMI, β-HCH and p,p'-DDT concentrations were significantly associated with a decreased TL in the overweight pre-pregnancy BMI group [-0.111 (95% CI: -0.203, -0.018) and -0.036 (95% CI: -0.049, -0.023), respectively]. Conclusions: Prenatal exposure to OCPs during pregnancy was associated with a decreased neonatal telomere length, which may be affected by the newborn sex and pre-pregnancy BMI. These findings may provide new insights into the mechanisms underlying OCP-induced adverse health effects.

RevDate: 2024-11-26
CmpDate: 2024-11-26

Hong L, Xu XD, Yang L, et al (2024)

Construction and analysis of telomere-to-telomere genomes for 2 sweet oranges: Longhuihong and Newhall (Citrus sinensis).

GigaScience, 13:.

BACKGROUND: Sweet orange (Citrus sinensis Osbeck) is a fruit crop of high nutritional value that is widely consumed around the world. However, its susceptibility to low-temperature stress limits its cultivation and production in regions prone to frost damage, severely impacting the sustainable development of the sweet orange industry. Therefore, developing cold-resistant sweet orange varieties is of great necessity. Traditional hybrid breeding methods are not feasible due to the polyembryonic phenomenon in sweet oranges, necessitating the enhancement of its germplasm through molecular breeding. High-quality reference genomes are valuable for studying crop resistance to biotic and abiotic stresses. However, the lack of genomic resources for cold-resistant sweet orange varieties has hindered the progress in developing such varieties and researching their molecular mechanisms of cold resistance.

FINDINGS: This study integrated PacBio HiFi, ONT, Hi-C, and Illumina sequencing data to assemble telomere-to-telomere (T2T) reference genomes for the cold-resistant sweet orange mutant "Longhuihong" (Citrus sinensis [L.] Osb. cv. LHH) and its wild-type counterpart "Newhall" (C. sinensis [L.] Osb. cv. Newhall). Comprehensive evaluations based on multiple criteria revealed that both genomes exhibit high continuity, completeness, and accuracy. The genome sizes were 340.28 Mb and 346.33 Mb, with contig N50 of 39.31 Mb and 36.77 Mb, respectively. In total, 31,456 and 30,021 gene models were annotated in the respective genomes. Leveraging these assembled genomes, comparative genomics analyses were performed, elucidating the evolutionary history of the sweet orange genome. Moreover, the study identified 2,886 structural variants between the 2 genomes, with several SVs located in the upstream, downstream, or intronic regions of homologous genes known to be associated with cold resistance.

CONCLUSIONS: The study de novo assembled 2 T2T reference genomes of sweet orange varieties exhibiting different levels of cold tolerance. These genomes serve as valuable foundational resources for genomic research and molecular breeding aimed at enhancing cold tolerance in sweet oranges. Additionally, they expand the existing repository of reference genomes and sequencing data resources for C. sinensis. Moreover, these genomes provide a critical data foundation for comparative genomics analyses across different plant species.

RevDate: 2024-11-26
CmpDate: 2024-11-26

Hassan R, Bhat GR, Mir FA, et al (2024)

Concomitant telomere attrition is associated with spinal muscular atrophy in highly inbred region of North India: unraveling the thread in Kashmir region.

BMC medical genomics, 17(1):275.

Spinal muscular atrophy (SMA) is a rare genetic disorder that unequivocally results in the degeneration of motor neurons, leading to muscle weakness and atrophy. This condition is caused by a mutation in the survival motor neuron 1 (SMN1) gene, which inevitably results in a deficiency of the SMN protein. In present study, we investigated the potential role of telomere attrition in SMA patients. Relative telomere length in peripheral blood lymphocytes was measured by Monochrome Multiplex Quantitative Polymerase Chain Reaction (MMQPCR) in 98 subjects and we conclusively found that SMA cases exhibit telomere attrition compared to healthy controls (P = 4 × 10[- 2]). Moreover, significant attrition was also observed in severe form of SMA, i.e. SMA type 0 (P = 0.04) as well.Although, the exact mechanism through which telomere shortening contributes to the pathogenesis of SMA is not fully understood and is yet to be delineated. However, one possibility is that telomere shortening leads to genomic instability and DNA damage, which can contribute to motor neuron degeneration. Another possibility is that telomere shortening leads to cellular senescence, which can impair the ability of motor neurons to regenerate and repair themselves. Recent studies have suggested that telomere shortening may be a potential therapeutic target in SMA. Thus, understanding the role of SMN1 gene in disease pathogenesis & its effect on telomere length will aid in estimating the risk & prognosis of SMA in genetically less explored & highly inbred region of Kashmir, Northern India.

RevDate: 2024-11-25

Baird DM (2024)

Telomere Dynamics in Human Health and Disease.

Cold Spring Harbor perspectives in biology pii:cshperspect.a041701 [Epub ahead of print].

Telomere function is critical for genomic stability; in the context of a functional TP53 response, telomere erosion leads to a G1/S cell-cycle arrest and the induction of replicative senescence, a process that is considered to underpin the ageing process in long-lived species. Abrogation of the TP53 pathway allows for continued cell division, telomere erosion, and the complete loss of telomere function; the ensuing genomic instability facilitates clonal evolution and malignant progression. Telomeres display extensive length heterogeneity in the population that is established at birth, and this affects the individual risk of a broad range of diseases, including cardiovascular disease and cancer. In this perspective, I discuss telomere length heterogeneity at the levels of the population, individual, and cell, and consider how the dynamics of these essential chromosomal structures contribute to human disease.

RevDate: 2024-11-25

Kaliman P, Álvarez-López MJ, Lehodey A, et al (2025)

Effect of an 18-Month Meditation Training on Telomeres in Older Adults: A Secondary Analysis of the Age-Well Randomized Controlled Trial.

Biological psychiatry global open science, 5(1):100398.

BACKGROUND: Shorter telomeres are associated with increased risk of cognitive decline and age-related diseases. Developing interventions to promote healthy aging by preserving telomere integrity is of paramount importance. Here, we investigated the effect of an 18-month meditation intervention on telomere length (TL) measures in older people without cognitive impairment.

METHODS: A total of 137 adults age ≥65 years were randomized to one of the 3 groups (meditation training, non-native language training, or passive control). We evaluated the 50th and 20th percentile TL and the percentage of critically short telomeres (<3 kbp) in peripheral blood mononuclear cells.

RESULTS: Mixed model analysis showed a time effect indicating a general decrease on the 50th percentile TL (F = 80.72, p adjusted < .001), without a significant group effect or time × group interaction. No significant effect was detected in the 20th percentile TL or the percentage of critically short telomeres. Secondary analysis showed that only in the meditation training group 1) the 50th percentile TL positively correlated with class attendance time (r = 0.45, p adjusted < .011), 2) the 50th and 20th percentile TL positively correlated with responsiveness to the intervention, evaluated through a composite score (r = 0.46, p adjusted < .010 and r = 0.41, p adjusted = .029, respectively), and 3) lower scores on a measure of the personality trait "openness to experience" correlated with a lower percentage of critically short telomeres after the intervention (r = 0.44, p adjusted = .015).

CONCLUSIONS: In older adults, we found no evidence for a main effect of an 18-month meditation training program on TL compared with the control groups. Our findings highlight the importance of considering the impact of moderating factors when measuring the effectiveness of meditation-based trainings.

RevDate: 2024-11-23

Li P, Meng L, Tu H, et al (2024)

The impact of Radioresistant-Related Telomere Genes in the prognosis and immune infiltration in lung adenocarcinoma.

Cancer cell international, 24(1):387.

INTRODUCTION: Lung adenocarcinoma (LUAD), a common subtype of NSCLC, has a high mortality rate. Telomere genes are influenced by radiation therapy, affecting treatment response. Additionally, immune cell presence in the tumor microenvironment plays a crucial role in cancer prognosis. However, the role of Radioresistant-Related Telomere Genes (RRTGs) in LUAD prognosis and immune infiltration remains unclear.

METHODS: In this research, we utilized diverse bioinformatics techniques to examine our personally tested information along with publicly accessible datasets. We conducted a comprehensive study on the genetic and transcriptional differences, predictive significance, and expression profiles of RRTGs. Afterwards, a RRTGs score was developed to forecast the overall survival (OS) and ascertain its reliable predictive capacity for patients with LUAD. Following this, dependable nomograms were developed to enhance the practicality of RRTGs scoring in a clinical setting. Furthermore, the investigation delved into the associations among RRTGs, infiltration of immune cells, prognosis, and clinical treatments of patients. Gene Set Enrichment Analysis (GSEA) was conducted to explore the potential mechanisms by which RRTGs influence the regulation of LUAD. Then, Western blot, qRT-PCR and Immunohistochemistry were used to detect the expression levels of RRTGs in cell lines and LUAD tumor tissues.

RESULTS: Our research indicates that certain genes related to telomeres have a notable correlation with the prognosis of patients diagnosed with LUAD. The RRTGs score, which includes three key genes (ARRB1, PLK1, and DSG2), was developed to forecast the OS and its dependable predictive capability for individuals diagnosed with LUAD was ascertained. Afterwards, extremely reliable nomograms were developed to improve the practicality of the RRTGs score. Moreover, as illustrated, genetic characteristics can be utilized to assess the infiltration of immune cells in tumors, as well as clinical attributes and prognosis. RRTGs score characterizes tumor mutational burden, immune activity, and notable survival probabilities in addition. Furthermore, GSEA results revealed that RRTGs may influence LUAD by modulating immune-related pathways in high-risk groups and regulating cell cycle and DNA repair processes in low-risk groups. The RRTGs (ARRB1 and PLK1) were upregulated in A549 cells and radiosensitive NSCLC tissues compared to radioresistant A549 cells and NSCLC tissues.

CONCLUSION: In conclusion, this research emphasizes the significance of RRTGs in the outlook of LUAD. The findings contributed to a better understanding of the link between radiotherapy, telomere-related genes, and prognosis in LUAD, and identified potential therapeutic targets for patients with LUAD.

RevDate: 2024-11-23
CmpDate: 2024-11-23

Lu S, Liu Y, Li M, et al (2024)

Gap-free telomere-to-telomere haplotype assembly of the tomato hind (Cephalopholis sonnerati).

Scientific data, 11(1):1268.

The tomato hind (Cephalopholis sonnerati) is an emerging economically important grouper in recent years. With the increasing maturity of sequencing technologies and assembly methodologies, a higher quality reference genome has become both accessible and necessary. In this study, we present two telomere-to-telomere (T2T) gap-free haplotype assemblies of the tomato hind with lengths of 1039.53 Mb (YSFRI_Csonn_HA_1.0, N50 43.83 Mb) and 1039.91 Mb (YSFRI_Csonn_HB_1.0, N50 44.09 Mb). Reads from next-generation sequencing, ONT ultra-long sequencing, and PacBio HiFi sequencing exhibited mapping rates exceeding 99.8% when aligned to these two assemblies. Evaluation using Merqury indicated high accuracy for both assemblies, with average quality values of 51.80 and 51.83, respectively. Percentages of 97.9% and 97.8% of complete BUSCOs were achieved, and a total of 23,270 and 23,184 protein-code genes were inferred in each assembly. Moreover, telomere identification, centromere prediction, and repetitive sequence annotation were also successfully performed. These two assemblies provide robust foundation for the genetic analysis and development of molecular genetic breeding technologies in C. sonnerati.

RevDate: 2024-11-22

Mohanty SK, Chiaromonte F, KD Makova (2024)

Evolutionary Dynamics of G-Quadruplexes in Human and Other Great Ape Telomere-to-Telomere Genomes.

bioRxiv : the preprint server for biology pii:2024.11.05.621973.

G-quadruplexes (G4s) are non-canonical DNA structures that can form at approximately 1% of the human genome. G4s contribute to point mutations and structural variation and thus facilitate genomic instability. They play important roles in regulating replication, transcription, and telomere maintenance, and some of them evolve under purifying selection. Nevertheless, the evolutionary dynamics of G4s has remained underexplored. Here we conducted a comprehensive analysis of predicted G4s (pG4s) in the recently released, telomere-to-telomere (T2T) genomes of human and other great apes-bonobo, chimpanzee, gorilla, Bornean orangutan, and Sumatran orangutan. We annotated tens of thousands of new pG4s in T2T compared to previous ape genome assemblies, including 41,236 in the human genome. Analyzing species alignments, we found approximately one-third of pG4s shared by all apes studied and identified thousands of species- and genus-specific pG4s. pG4s accumulated and diverged at rates consistent with divergence times between the studied species. We observed a significant enrichment and hypomethylation of pG4 shared across species at regulatory regions, including promoters, 5' and 3'UTRs, and origins of replication, strongly suggesting their formation and functional role in these regions. pG4s shared among great apes displayed lower methylation levels compared to species-specific pG4s, suggesting evolutionary conservation of functional roles of the former. Many species-specific pG4s were located in the repetitive and satellite regions deciphered in the T2T genomes. Our findings illuminate the evolutionary dynamics of G4s, their role in gene regulation, and their potential contribution to species-specific adaptations in great apes, emphasizing the utility of high-resolution T2T genomes in uncovering previously elusive genomic features.

RevDate: 2024-11-22

Peker Eyüboğlu İ, Koca S, Çelik B, et al (2024)

Neoadjuvant Chemotherapy Shortens the cfDNA Telomere Length in Breast Cancer Patients.

International journal of breast cancer, 2024:6117394.

Introduction: Cancer is a genetic disease that affects people worldwide, and breast cancer is the most common cancer in women. Studies have been conducted on molecular parameters to predict tumor behavior and develop therapeutic strategies. Telomeres, which are at the end of chromosomes, have been studied for their relationship with breast cancer, but more research is needed to understand their role in the disease. Circulating-free DNA (cfDNA) is DNA that is free in the bloodstream and is considered a promising target for early cancer detection, treatment response monitoring, and prognosis assessment. This study is aimed at comparing cfDNA telomere length of breast cancer patients and healthy individuals and analyzing the impact of neoadjuvant chemotherapy on telomere length in cfDNA. Materials and Methods: Blood samples were collected from 33 breast cancer patients undergoing neoadjuvant chemotherapy before and after treatment. The quantitative PCR method is used to measure the average telomere lengths. Results: This study found that the telomere length of cfDNA in breast cancer patients before and after treatment is significantly shorter than in the control group. Neoadjuvant chemotherapy is found to shorten the cfDNA telomere length, especially in the treatment-responsive group. Conclusion: Our study suggests that telomere length in cfDNA may be a useful biomarker for predicting therapy response and possible reoccurrence of the disease in breast cancer patients.

RevDate: 2024-11-22
CmpDate: 2024-11-22

Wang L, Zhang J, Liu F, et al (2024)

Maternal infection of SARS-CoV-2 during the first and second trimesters leads to newborn telomere shortening.

Journal of translational medicine, 22(1):1049.

BACKGROUND: Initial telomere length (TL) in newborns is the major determinant for TL in later life while TL in newborn/early-life predicts long-term health and lifespan. It is important to identify key factors that affect telomere homeostasis throughout embryonic development for precision interventions to maintain optimal TL in fetus/prenatal infants. SARS-CoV-2 has caused a widespread global pandemic of COVID-19, but it remains unclear whether maternal SARS-CoV-2 infection impairs prenatal telomere homeostasis.

METHODS: We recruited 413 normally delivered newborns whose mothers were either non-infected or infected with SARS-CoV-2 during different trimesters of pregnancy (otherwise healthy). Telomere length (TL) in cord blood (CB) was assessed using qPCR. CB and maternal blood were analyzed for cytokine levels. Placental senescence was determined using senescence-associated β-galactosidase staining.

RESULTS: Control (non-infected maternal) newborn TL was significantly longer than that from maternal infection (1.568 ± 0.340 vs 1.390 ± 0.350, P = 0.005). Such shorter TL was observed only if maternal infection of SARS-CoV-2 occurred in the first and second trimesters of pregnancy (1.261 ± 0.340 and 1.346 ± 0.353, P < 0.0001 and 0.001, respectively). There were no differences in TL between controls and infection at the third trimester (1.568 ± 0.340 vs 1.565 ± 0.329, P > 0.05). Across the first trimester, there was a positive correlation between newborn TL and gestational weeks with maternal infection, suggesting that the earlier maternal infection occurs, the worse effect is taken on fetal telomere homeostasis. Placental senescence coupled with the downregulated expression of telomerase reverse transcriptase was significantly more frequent from the maternal infection at the first trimester. There were no differences in IL-6, C reactive protein and other cytokine levels in CB and maternal serum or placentas.

CONCLUSIONS: Maternal SARS-CoV-2 infection at the first and second trimesters leads to significantly shorter TL and earlier infection causes much more severe TL damage. The infection-mediated cell senescence and other histopathological abnormalities result in defective placental function through which fetal telomere homeostasis is impaired. Thus, vaccination against COVID-19 should be done in advance for women who plan pregnancy.

RevDate: 2024-11-21

Di Pietro E, Burla R, La Torre M, et al (2024)

Telomeres: an organized string linking plants and mammals.

Biology direct, 19(1):119.

Telomeres are pivotal determinants of cell stemness, organismal aging, and lifespan. Herein, we examined similarities in telomeres of Arabidopsis thaliana, mice, and humans. We report the common traits, which include their composition in multimers of TTAGGG sequences and their protection by specialized proteins. Moreover, given the link between telomeres, on the one hand, and cell proliferation and stemness on the other, we discuss the counterintuitive convergence between plants and mammals in this regard, focusing on the impact of niches on cell stemness. Finally, we suggest that tackling the study of telomere function and cell stemness by taking into consideration both plants and mammals can aid in the understanding of interconnections and contribute to research focusing on aging and organismal lifespan determinants.

RevDate: 2024-11-20
CmpDate: 2024-11-20

Wu H, Luo LY, Zhang YH, et al (2024)

Telomere-to-telomere genome assembly of a male goat reveals variants associated with cashmere traits.

Nature communications, 15(1):10041.

A complete goat (Capra hircus) reference genome enhances analyses of genetic variation, thus providing insights into domestication and selection in goats and related species. Here, we assemble a telomere-to-telomere (T2T) gap-free genome (2.86 Gb) from a cashmere goat (T2T-goat1.0), including a Y chromosome of 20.96 Mb. With a base accuracy of >99.999%, T2T-goat1.0 corrects numerous genome-wide structural and base errors in previous assemblies and adds 288.5 Mb of previously unresolved regions and 446 newly assembled genes to the reference genome. We sequence the genomes of five representative goat breeds for PacBio reads, and use T2T-goat1.0 as a reference to identify a total of 63,417 structural variations (SVs) with up to 4711 (7.42%) in the previously unresolved regions. T2T-goat1.0 was applied in population analyses of global wild and domestic goats, which revealed 32,419 SVs and 25,397,794 SNPs, including 870 SVs and 545,026 SNPs in the previously unresolved regions. Also, our analyses reveal a set of selective variants and genes associated with domestication (e.g., NKG2D and ABCC4) and cashmere traits (e.g., ABCC4 and ASIP).

RevDate: 2024-11-20

Ferguson S, Bar-Ness YD, Borevitz J, et al (2024)

Correction: A telomere-to-telomere Eucalyptus regnans genome: unveiling haplotype variance in structure and genes within one of the world's tallest trees.

BMC genomics, 25(1):1107 pii:10.1186/s12864-024-10952-5.

RevDate: 2024-11-19

Panelli DM, Mayo JA, Wong RJ, et al (2024)

Corrigendum to "Mode of delivery predicts postpartum maternal leukocyte telomere length" [Eur. J. Obstetr. Gynecol. Reprod. Biol. 300 (2024) 224-229].

RevDate: 2024-11-19

Pedklang N, Navasumrit P, Chompoobut C, et al (2024)

Effects of particulate air pollution on BPDE-DNA adducts, telomere length, and mitochondrial DNA copy number in human exhaled breath condensate and BEAS-2B cells.

International journal of hygiene and environmental health, 263:114488 pii:S1438-4639(24)00169-X [Epub ahead of print].

Traffic-related particulate matter (PM) and polycyclic aromatic hydrocarbons (PAHs) have been linked to respiratory diseases and cancer risk in humans. Genomic damage, including benzo[a]pyrene diolepoxide (BPDE)-DNA adducts as well as alterations in telomere length (TL) and mitochondrial DNA copy number (mtDNA-CN) are associated with respiratory diseases. This study aimed to investigate the association between exposure to traffic-related particulate pollutants and genomic damage in exhaled breath condensate (EBC) in human subjects and a bronchial epithelial cell line (BEAS-2B). Among the 60 healthy recruited subjects, residents living in high-traffic-congested areas were exposed to higher concentrations of PM2.5 (1.66-fold, p < 0.01), UFPs (1.79-fold, p < 0.01), PM2.5-PAHs (1.50-fold, p < 0.01), and UFPs-PAHs (1.35-fold, p < 0.05), than those in low-traffic-congested areas. In line with increased exposure to particulate air pollution, the high-traffic-exposed group had significantly increased BPDE-DNA adducts (1.40-fold, p < 0.05), TL shortening (1.24-fold, p < 0.05), and lower mtDNA-CN (1.38-fold, p < 0.05) in EBC. The observations in the human study linking exposure to PM2.5, UFPs, PM2.5-PAHs, and UFPs-PAHs with the aforementioned biological effects were confirmed by an in vitro cell-based study, in which BEAS-2B cells were treated with diesel exhaust particulate matter (DEP) containing fine and ultrafine PM and PAHs. Increased BPDE-DNA adducts levels, shortened TL, and decreased mtDNA-CN were also found in treated BEAS-2B cells. The shortened TL and decreased mtDNA-CN were in part mediated by decreased transcript levels of hTERT, and SIRT1, which are involved in telomerase activity and mitochondrial biogenesis, respectively. These results suggest that exposure to traffic-related particulate pollutants can cause genomic instability in respiratory cells, which may increase the health risk of respiratory diseases and the development of cancer.

RevDate: 2024-11-18

Laemmerer A, Lehmann C, Mayr L, et al (2024)

Alternative lengthening of telomere-based immortalization renders H3G34R -mutant diffuse hemispheric glioma hypersensitive to PARP inhibitor combination regimens.

Neuro-oncology pii:7903167 [Epub ahead of print].

BACKGROUND: Diffuse hemispheric glioma, H3G34R/V-mutant (DHG-H3G34) is characterized by poor prognosis and lack of effective treatment options. DHG-H3G34R further harbor deactivation of Alpha-Thalassemia/Mental Retardation Syndrome X-linked protein (ATRX; DHG-H3G34R_ATRX) suggesting a unique interaction of these two oncogenic alterations. In this study, we dissect their cell biological interplay, investigate the impact on telomere stabilization and, consequently, validate a targeted therapy approach.

METHODS: We characterized patient-derived primary pediatric high-grade glioma (pHGG) models for telomere-maintenance mechanisms, DNA damage stress (including protein expression, pH2AX/Rad51 foci, cell-cycle arrest) and their sensitivity towards poly-ADP polymerase inhibitor (PARPi) combinations. Human induced pluripotent stem cells (iPSCs) were used for modelling the disease. The anticancer activity of PARPi combinations in vivo was studied in Chorioallantoic Membrane (CAM) and orthotopic in vivo experiments. Finally, we treated a DHG-H3G34R_ATRX patient with a PARPi combination therapy.

RESULTS: We elaborate that alternative lengthening of telomeres (ALT) is a key characteristic of DHG-H3G34R_ATRX. A dominant cooperative effect between H3G34R and ATRX loss in ALT activation also became apparent in iPSCs, which endogenously exert telomerase activity. In both, patient-derived DHG-H3G34R_ATRX models and H3G34R+/ATRX- iPSCs, the ALT phenotype was associated with increased basal DNA damage stress, mediating synergistic susceptibility towards PARPi (talazoparib, niraparib) combinations with topoisomerase-I inhibitors (topotecan, irinotecan). In a first-of-its-kind case, treatment of a DHG-H3G34R_ATRX patient with the brain-penetrant PARP inhibitor niraparib and topotecan resulted in a significant tumor reduction.

CONCLUSION: Our preclinical and clinical data strongly support the further development of PARPis together with DNA damage stress-inducing treatment regimens for DHG-H3G34R_ATRX.

RevDate: 2024-11-18

Pearce E, Majid A, Brown T, et al (2024)

A "rotating menu" of medical uncertainty for families affected by telomere biology disorders: A qualitative interview study.

SSM. Qualitative research in health, 6:.

BACKGROUND: Medical uncertainty may cause distress and challenge medical decision-making for patients with rare diseases and their caregivers. Few studies have examined the experience and management of medical uncertainty in rare disease and the dynamics of multiple medical uncertainty sources, issues, and management strategies.

OBJECTIVE: We explored the experience and management of uncertainty in individuals with telomere biology disorders (TBDs), a set of rare cancer-prone bone marrow failure syndromes, and their caregivers.

DESIGN: Participants (N=32) in this qualitative-descriptive study were individuals with a TBD (n=17) and/or their caregivers (n=15). We thematically analyzed transcripts to describe the presence and dynamics of medical uncertainty in TBDs using categories from a previously published taxonomy.

RESULTS: Individuals with TBDs and caregivers described medical uncertainty as a chronic burden embodied amidst a range of interrelated sources and issues. Scientific uncertainty included diagnostic and prognostic ambiguity. Practical uncertainty focused on logistical challenges of building and maintaining medical care teams. Personal uncertainty included difficulty realigning self-identity, goals, and relationship expectations post-diagnosis. Scientific, practical, and personal uncertainty issues were entangled. The rarity of TBDs resulted in limited scientific knowledge, which gave rise to practical and personal uncertainties affecting medical decision-making and relationship formation (e.g., creating trusted care teams where patient knowledge of TBDs may exceed that of clinicians). Participants used multiple strategies for uncertainty management, particularly information-seeking and community-building. However, these management strategies could intensify, rather than resolve, participants' medical uncertainty.

CONCLUSION: In TBDs, medical uncertainty manifests as a network of multiple, interrelated, sources and issues, which require evolving management strategies. Researchers must be mindful that complex, synergistic uncertainty networks contribute to psychosocial challenges in TBDs. Additional research is warranted to address scientific uncertainty in TBDs, including clinical manifestations and underlying biology, and to develop psychosocial interventions that recognize and anticipate evolving uncertainty.

RevDate: 2024-11-18

Chung G, Piano F, KC Gunsalus (2024)

TeloSearchLR: an algorithm to detect novel telomere repeat motifs using long sequencing reads.

bioRxiv : the preprint server for biology pii:2024.10.29.617943.

Telomeres are eukaryotic chromosome end structures that guard against sequence loss and aberrant chromosome fusions. Telomeric repeat motifs (TRMs), the minimal repeating unit of a telomere, vary from species to species, with some evolutionary clades experiencing a rapid sequence divergence. To explore the full scope of this evolutionary divergence, many bioinformatic tools have been developed to infer novel TRMs using repetitive sequence search on short sequencing reads. However, novel telomeric motifs remain unidentified in up to half of the sequencing libraries assayed with these tools. A possible reason may be that short reads, derived from extensively sheared DNA, preserve little to no positional context of the repetitive sequences assayed. On the other hand, if a sequencing read is sufficiently long, telomeric sequences must appear at either end rather than in the middle. The TeloSearchLR algorithm relies on this to help identify novel TRMs on long reads, in many cases where short-read search tools have failed. In addition, we demonstrate that TeloSearchLR can reveal unusually long telomeric motifs not maintained by telomerase, and it can also be used to anchor terminal scaffolds in new genome assemblies.

RevDate: 2024-11-18

Packer A, Habiballa L, Tato-Barcia E, et al (2024)

Telomere length and cognitive changes in 7,877 older UK adults of European ancestry.

Frontiers in aging, 5:1480326.

BACKGROUND: Telomere length (TL) has been linked to cognitive function, decline and dementia. This study aimed to explore whether both measured TL and genetic disposition for TL predict dimensions of cognitive performance in a longitudinal sample of older UK adults.

METHODS: We analysed data from PROTECT study participants aged ≥50 years without a dementia diagnosis, who had completed longitudinal cognitive testing. We calculated polygenic scores for telomere length (PGS-TL) for 7,877 participants and measured relative telomere length (RTL) in a subgroup of 846 participants using DNA extracted from saliva samples collected within 6 months either side of their baseline cognitive testing. Latent growth models were used to examine whether RTL and PGS-TL predict both baseline and longitudinal changes in cognitive performance (4 time-points, annually).

RESULTS: In the whole sample, we did not observe significant associations between either measure of telomere length and initial or longitudinal changes in cognitive performance. Stratifying by median age, in older adults (≥ ∼62 years), longer baseline RTL showed a nominal association with poorer baseline verbal reasoning performance (n = 423, M intercept = 47.58, B = -1.05, p = .011) and PGS-TL was associated with performance over time (n = 3,939; slope factor, M slope = 3.23, B = -0.45, p = .001; slope [2] factor, M slope [2] = 0.21, B = 0.13, p = .002).

CONCLUSION: Our findings suggest either the absence of a significant relationship between telomere length (RTL and PGS-TL) and cognitive performance (baseline and change over time), or possibly a weak age-dependent and domain-specific relationship, in older adults of European ancestry. More research is needed in representative and ancestrally diverse samples over a longer assessment period. Alternative biological ageing indicators may still provide utility in the early detection of individuals at risk for cognitive decline (e.g., pace-of ageing epigenetic clocks).

RevDate: 2024-11-18

Xie S, Xiao H, Zhang F, et al (2024)

Identification and Validation of Telomere-Related Gene Signature in Intervertebral Disc Degeneration.

Cureus, 16(10):e71735.

This study investigates the role of telomere-related differentially expressed genes (TRDEGs) in intervertebral disc degeneration (IVDD) through comprehensive bioinformatics analyses. Data were sourced from the Gene Expression Omnibus (GEO) with datasets GSE245147 and GSE124272 used for initial identification and validation, respectively. The GSE245147 dataset comprised transcriptional profiles from nucleus pulposus cells of both degenerated and non-degenerated human nucleus pulposus (NP) tissues. Using the limma package, 198TRDEGs were identified by intersecting differentially expressed genes (DEGs) with telomere-related genes (TRGs) from the TelNet database. Functional enrichment analyses using the Database for Annotation, Visualization and Integrated Discovery (DAVID) revealed that TRDEGs are significantly involved in cell division, chromosome segregation, and other mitotic processes. Protein-protein interaction (PPI) networks constructed using the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database and visualized with Cytoscape (Cytoscape Consortium, San Diego, CA, USA) identified key hub genes such as CDK1, CCNA2, and AURKB. Pearson correlation and receiver operating characteristic (ROC) analyses highlighted five hub genes (ASPM, BUB1B, CDC20, KIF2C, TTK) with significant predictive value for IVDD. Additionally, mRNA-microRNA (miRNA) interaction analysis using NetworkAnalyst identified key miRNAs interacting with these hub genes. This study provides insights into the molecular mechanisms of IVDD and identifies potential targets for therapeutic intervention.

RevDate: 2024-11-15
CmpDate: 2024-11-16

Piras M, Lin J, Sadler MC, et al (2024)

Psychotropic-induced weight gain and telomere length: results from a one-year longitudinal study and a large population-based cohort.

Translational psychiatry, 14(1):471.

Weight-inducing psychotropic treatments are risk factors for age-related diseases such as cardiovascular disorders, which are associated with both inflammation and telomere length shortening. With a longitudinal design, the present study evaluates telomere length trajectories after 1 year of weight-inducing psychotropic medication, accounting for weight changes and the inflammatory biomarker high-sensitivity C-Reactive Protein (CRP). Among 200 patients, an overall median telomere shortening of -41.2 bp was observed (p = 0.014), which is comparable with the general population's yearly telomere attrition. Linear regression showed on average -93.1 and -58.9 bp of further telomere shortening per five units of BMI for BMI values < or ≥30 kg/m[2], respectively (p = 0.003 and p = 0.009, respectively). Importantly, the overall telomere shortening was predicted to be increased four-fold among patients with low baseline weight (i.e., 50 kg) and with clinically relevant weight gain (≥ 7%) after 1 year of treatment (interaction term between relevant weight gain and baseline weight: +6.3 bp, p = 0.016). Patients with relevant weight gain showed greater CRP levels (+ 49%; p = 0.016), and a telomere shortening of -36.2 bp (p = 0.010) was estimated whenever CRP level doubled. Mendelian randomization using UKBiobank data showed a causal effect of BMI on telomere shortening, notably stronger among patients receiving weight-inducing psychotropic treatments (n = 9798) than among psychiatric patients without such drugs (n = 16228) and non-psychiatric controls (n = 252932) (beta: -0.37, -0.12, -0.06, respectively; p = 0.004, p < 0.001, p < 0.001, respectively). Ultimately, telomere trajectories were associated with 1 year weight gain and increases in CRP levels, with telomere shortening strongly enhanced by BMI increments among patients receiving weight-inducing psychotropic treatments.

RevDate: 2024-11-15

Muñoz-Pardeza J, López-Gil JF, Huerta-Uribe N, et al (2024)

Is physical fitness associated with leucocyte telomere length in youth with type 1 diabetes?.

Pediatric research [Epub ahead of print].

BACKGROUND: In type 1 diabetes, telomere length (TL) may predict complications and could be influenced by glycaemic control and physical activity, but its relationship with physical fitness in youths remains unexplored. The aim of the study was to assess the association between physical fitness and TL in youth with type 1 diabetes, both at baseline and one year later.

METHODS: Eighty-three children and adolescents (aged 6-18 years; 44.6% girls) with type 1 diabetes from the Diactive-1 Cohort Study were involved in this study. Physical fitness was assessed using spirometry on a cycloergometer (i.e., peak oxygen consumption), dynamometry, and maximal isometric strength (one-repetition maximum [1RM]), and muscle power. Leucocyte TL was assessed using multiplex monochrome real-time quantitative polymerase chain reaction.

RESULTS: Positive cross-sectional associations were identified between 1RM (unstandardized beta coefficient [B] = 0.042, 95% bias corrected and accelerated [BCa] confidence interval [CI] 0.012-0.069), muscle power (B = 0.056, 95% BCa CI 0.02-0.250), and overall physical fitness (B = 0.043, 95% BCa CI 0.015-0.071) with TL independent of maturation, glycated haemoglobin, and diabetes duration. However, no associations were observed one year later.

CONCLUSION: Higher levels of fitness, particularly muscle strength, may play a role in telomere dynamics in youth with type 1 diabetes, suggesting that strength training exercise could be beneficial.

IMPACT: This is the first study to examine cross-sectional and longitudinal perspectives on the correlation among muscle strength, peak oxygen consumption [VO2peak] and telomere length in youths with type 1 diabetes. Higher physical fitness levels, as assessed by measures such as one-repetition maximum, muscle power, and overall physical fitness, are positively associated with telomere length in youths with type 1 diabetes. Understanding this link could improve management strategies, prioritizing muscle strength training for better long-term health in type 1 diabetes.

RevDate: 2024-11-13

da Cunha Agostini L, GN da Silva (2024)

Telomere length as a biomarker for cerebrovascular diseases: current evidence.

Molecular biology reports, 51(1):1150.

Cerebrovascular disease (CVD) includes a range of conditions affecting the brain's blood vessels, which can result in reduced blood flow to brain tissue. The most common manifestation of CVD is stroke, the second leading cause of death and the third leading cause of disability worldwide. Major risk factors for CVD encompass gender, age, smoking, hypertension, diabetes, physical inactivity, obesity, alcohol consumption, and metabolic syndrome. Research suggests a link between telomere length and an increased risk of CVD, particularly in ischemic stroke cases. This review highlights key findings on the relationship between telomere length and CVD, underscoring its clinical importance. The analysis utilizes scientific literature from PubMed, Scopus, and SciELO up to 2024. Results show that shorter telomere length is associated with various types of CVD, including stroke, ischemic stroke, hemorrhagic stroke, and cardioembolic stroke. Some studies propose that telomere length measurement could be a valuable biomarker for CVD, potentially improving prevention, diagnosis, and management strategies.

RevDate: 2024-11-13
CmpDate: 2024-11-13

Katneni VK, Krishnan K, Prabhudas SK, et al (2024)

Genome assembly at chromosome scale with telomere ends for Pearlspot, Etroplus suratensis.

Scientific data, 11(1):1226.

The pearlspot, Etroplus suratensis is a climate resilient cichlid fish that exhibits unusual adaptation to salinity. The fish is able to complete full life cycle in diverse salinity habitats ranging from fresh water to marine environments. High-quality primary and phased genome assemblies were generated for pearlspot fish using PacBio HiFi and Arima HiC sequencing technologies, for the first time. The primary assembly is highly contiguous with contig N50 length of 36 Mb. The final assembly is of 1.247 Gb with N50 length of 51.57 Mb and 98% of the genome length anchored to 24 chromosomes. The genome was assessed to be 99.9% complete based on BUSCO evaluation and was predicted to contain 52.96% repeat elements. We have predicted 27,192 protein encoding genes, of which 21,580 were functionally annotated. The genome offers an invaluable resource to understand adaptation of pearlspot fish to diverse salinity habitats.

RevDate: 2024-11-13
CmpDate: 2024-11-13

Li J, Hu L, X Huang (2024)

Causal relationship between leukocyte telomere length and two cardiomyopathies based on a bidirectional Mendelian randomization approach.

Medicine, 103(45):e40308.

This study aims to employ the Mendelian randomization (MR) approach to investigate the relationship between leukocyte telomere length (TL) and 2 prevalent forms of cardiomyopathies. Using R software (4.3.1) for MR study, independent genetic variants associated with leukocyte TL were extracted from the Integrative Epidemiology Unit database, while cardiomyopathies data were pooled from FinnGen and European Bioinformatics Institute databases. Analytical methodologies included inverse-variance weighting, MR-Egger regression, and weighted median methods. Further analyses involved MR-Egger intercept and MR-PRESSO for handling horizontal pleiotropy and Cochran Q test for study heterogeneity. Our forward Mendelian randomization study indicates a positive correlation between longer leukocyte TL and the risk of 2 forms of cardiomyopathies: the longer the leukocyte telomere, the higher is the risk of cardiomyopathies. Specifically, for hypertrophic obstructive cardiomyopathy the OR is 2.23 (95% CI: 1.19-4.14, P = .01), for hypertrophic cardiomyopathy the OR is 1.80 (95% CI: 1.14-2.85, P = .01), and for dilated cardiomyopathy the OR is 1.32 (95% CI: 1.01-1.71, P = .04). In contrast, our reverse Mendelian randomization showed that cardiomyopathies were not directly associated with TL, and the inverse-variance-weighted test was not statistically significant for any of the 3 (P > .05). The reliability tests for the forward Mendelian randomization, including both MR-Egger intercept and MR-PRESSO tests, show no evidence of horizontal pleiotropy, and Cochran Q test indicates no heterogeneity. The "leave-one-out" sensitivity analysis revealed no outlier genes. The reliability tests for the reverse Mendelian randomization, including both MR-Egger intercept and MR-PRESSO tests, also indicate no genetic pleiotropy. Despite the heterogeneity shown in our study between hypertrophic cardiomyopathy and leukocyte TL, the sensitivity analysis did not identify any anomalies. Our Mendelian randomization study suggests that longer leukocyte TL is associated with an increased risk of hypertrophic obstructive cardiomyopathy, hypertrophic cardiomyopathy, and dilated cardiomyopathy. However, the onset of these 2 kinds of disease does not directly lead to changes in leukocyte TL.

RevDate: 2024-11-11

Mazumdar J, Chowdhury P, Mondal BC, et al (2024)

Elevated Telomeric Repeat-Containing RNA (TERRA) Levels Linked to Telomere Dysfunction and Telomerase Inactivity in Blood Cells of Children With Aplastic Anemia.

Cureus, 16(10):e71241.

Background Aplastic anemia (AA) is characterized by pancytopenia and hypocellularity of the bone marrow. Certain inherited or genetic forms of AA have also been associated with telomere dysfunction. Here, we report the clinical manifestations of eleven AA patients aged between one and 12 years, along with the expression of a few candidate genes involved in the telomere length (TL) maintenance pathway. Methods The clinical manifestations were recorded for all the patients. The average telomere length of peripheral blood mononuclear cells (PBMC), the expression of telomerase subunits, telomere-associated proteins, and chromosome-specific telomeric repeat-containing RNA (TERRA) in whole blood cells of each patient was compared with an age-matched control group consisting of five clinically confirmed normal individuals. Results Out of 11 AA patients, four were found to have upper limb anomalies, and two showed short stature along with other defects. All the patients showed significantly shorter telomere length compared with the age-matched control group. The essential subunits of telomerase (hTERT and hTERC) were significantly low, and the shelterin protein is abnormally expressed in all patients implicating a compromised TL maintenance pathway. Notably, AA with combined androgen and prednisolone treatment showed a marked reduction of TERRA level than that of AA without androgen/prednisolone therapy. Conclusion Based on the findings and observations made, it appears that there might be an association between telomere dysfunction and elevated levels of TERRA in patients diagnosed with aplastic anemia who are 12 years of age or younger.

RevDate: 2024-11-08

Amatya S, Bhatia P, Raina S, et al (2024)

Corrigendum to "Clinical utility of relative telomere length analysis in pediatric bone marrow failure" [Blood Cells Mol. Dis. 109 (2024) 102882].

RevDate: 2024-11-08
CmpDate: 2024-11-08

Knecht H, Petrogiannis-Haliotis T, Louis S, et al (2024)

3D-Q-FISH/Telomere/TRF2 Nanotechnology Identifies a Progressively Disturbed Telomere/Shelterin/Lamin AC Complex as the Common Pathogenic, Molecular/Spatial Denominator of Classical Hodgkin Lymphoma.

Cells, 13(21): pii:cells13211748.

The bi- or multinucleated Reed-Sternberg cell (RS) is the diagnostic cornerstone of Epstein-Barr Virus (EBV)-positive and EBV-negative classical Hodgkin lymphoma (cHL). cHL is a germinal center (GC)-derived B-cell disease. Hodgkin cells (H) are the mononuclear precursors of RS. An experimental model has to fulfill three conditions to qualify as common pathogenic denominator: (i) to be of GC-derived B-cell origin, (ii) to be EBV-negative to avoid EBV latency III expression and (iii) to support permanent EBV-encoded oncogenic latent membrane protein (LMP1) expression upon induction. These conditions are unified in the EBV-, diffuse large B-Cell lymphoma (DLBCL) cell line BJAB-tTA-LMP1. 3D reconstructive nanotechnology revealed spatial, quantitative and qualitative disturbance of telomere/shelterin interactions in mononuclear H-like cells, with further progression during transition to RS-like cells, including progressive complexity of the karyotype with every mitotic cycle, due to BBF (breakage/bridge/fusion) events. The findings of this model were confirmed in diagnostic patient samples and correlate with clinical outcomes. Moreover, in vitro, significant disturbance of the lamin AC/telomere interaction progressively occurred. In summary, our research over the past three decades identified cHL as the first lymphoid malignancy driven by a disturbed telomere/shelterin/lamin AC interaction, generating the diagnostic RS. Our findings may act as trailblazer for tailored therapies in refractory cHL.

RevDate: 2024-11-08

Zhu S, Zheng W, Rao D, et al (2024)

Leukocyte telomere length and lung function: a mendelian randomization study in European population.

Frontiers in physiology, 15:1373064.

BACKGROUND: The telomere has long been regarded as a dependable biomarker for cellular senescence. The lung function can reflect the function and status of the lungs. As individuals age beyond adulthood, there is a gradual decline in lung function. However, the existence of a associated between leukocyte telomere length (LTL) and lung function remains uncertain.

METHODS: A two-sample Mendelian randomization (MR) analysis was used. The Single-nucleotide polymorphisms (SNPs) of LTL from the genome-wide association (GWAS) study were used as exposure instruments variable, and the lung function indicator including Forced expiratory volume in 1-s (FEV1), FEV1 Best measure, FEV1 predicted and Forced vital capacity (FVC) from the Neale Lab and MRC-IEU were used as outcomes. The associated between the exposures and outcomes was assessed using inverse-variance weighted (IVW), MR-Egger, and weighted median methods. Sensitivity analysis was conducted using Cochran's Q-test, MR-Egger intercept test, MR-PRESSO, leave-one-out analysis, and Steriger test.

RESULTS: Using the IVW method, a significant association was identified between genetically determined telomere length extension and enhanced lung function in FEV1, with ukb-a-336 (P = 0.127, OR = 1.028,95CI% = 1.003-1.042) and ukb-b-19657 (P = 7.26E-05, OR = 1.051,95CI% = 1.025-1.077),in FEV1 predicted, ukb-a-234 (P = 0.013, OR = 1.029,95CI% = 1.003-1.042), ukb-b-8428 (P = 0.001, OR = 1.032,95CI% = 1.012-1.052), in FEV1 best measure, ukb-a-231 (P = 7.24E-05, OR = 1.050,95CI% = 1.025-1.075), ukb-b-11141 (P = 1.40E-09, OR = 1.067,95CI% = 1.045-1.090).The sensitivity analysis did not reveal heterogeneity or horizontal pleiotropy.Meanwhile, the Steriger test results also indicate that the directionality between exposure and outcome is correct. Therefore, the results indicated robustness.

CONCLUSION: There is a correlation between longer LTL and better lung function in the European dataset.

RevDate: 2024-11-08

Hu T, Duan L, Shangguan L, et al (2024)

Haploid-Phased Chromosomal Telomere-to-Telomere Genome Assembly of Medicinal Plant Uncaria rhynchophylla Dissects Genetic Controls on the Biosynthesis of Bioactive Alkaloids.

Plant, cell & environment [Epub ahead of print].

Natural indole alkaloids provide important medicinal resources and defences to environmental stresses. The Uncaria genus is a recorded traditional medicinal woody plant with high alkaloids. Genomic insights into alkaloid variation remain elusive. Here, we have dissected the haploid-resolved chromosomal T2T genome assembly of Uncaria rhynchophylla with a size of ~634 Mb and contig N50 of 27 Mb using PacBio HiFi long-reads plus Hi-C reads and anchored the contigs on 22 pairs of confirmed chromosomes. This genome contains 56% repeat sequences and ~29 000 protein-encoding genes. U. rhynchophylla diverged from a common ancestor shared with Coffea around 20 million years ago and contains expanded and contracted gene families associated with secondary metabolites and defences/resistance to stresses. We constructed the pathway and mined genes for rhynchophylline alkaloid biosynthesis. Fifty-three alkaloids in this pathway and eight differentially expressed genes are the keys to alkaloid accumulation. Elevated alkaloid levels are driven by high copy numbers of critical genes STRs and SGRs involved in strictosidine synthesis and hydrolysis as evidenced by phylogenetic, expression and RNA interference analyses. These results advance our genetic understanding and guide further breeding improvements, stress adaptation studies and pharmaceutical development.

RevDate: 2024-11-07

Lynskey ML, Brown EE, Bhargava R, et al (2024)

HIRA protects telomeres against R-loop-induced instability in ALT cancer cells.

Cell reports, 43(11):114964 pii:S2211-1247(24)01315-9 [Epub ahead of print].

Inactivating mutations in chromatin modifiers, like the α-thalassemia/mental retardation, X-linked (ATRX)-death domain-associated protein (DAXX) chromatin remodeling/histone H3.3 deposition complex, drive the cancer-specific alternative lengthening of telomeres (ALT) pathway. Prior studies revealed that HIRA, another histone H3.3 chaperone, compensates for ATRX-DAXX loss at telomeres to sustain ALT cancer cell survival. How HIRA rescues telomeres from the consequences of ATRX-DAXX deficiency remains unclear. Here, using an assay for transposase-accessible chromatin using sequencing (ATAC-seq) and cleavage under targets and release using nuclease (CUT&RUN), we establish that HIRA-mediated deposition of new H3.3 maintains telomeric chromatin accessibility to prevent the detrimental accumulation of nucleosome-free single-stranded DNA (ssDNA) in ATRX-DAXX-deficient ALT cells. We show that the HIRA-UBN1/UBN2 complex deposits new H3.3 to prevent TERRA R-loop buildup and transcription-replication conflicts (TRCs) at telomeres. Furthermore, HIRA-mediated H3.3 incorporation into telomeric chromatin links productive ALT to the phosphorylation of serine 31, an H3.3-specific amino acid, by Chk1. Therefore, we identify a critical role for HIRA-mediated H3.3 deposition that ensures the survival of ATRX-DAXX-deficient ALT cancer cells.

RevDate: 2024-11-12

Zhang B, Y Zhao (2024)

Association Analysis of Telomere Length and Vision in a Large Community-Based Survey.

Ophthalmic epidemiology [Epub ahead of print].

PURPOSE: To investigate whether there is a direct, age-independent association between telomere length and visual acuity decline in a large community-based cohort study.

METHODS: Participants older than 40 with linked leukocyte telomere length (LTL) were enrolled in NHANES. LTL was assayed using qPCR from the participants' blood samples. Best corrected visual acuity (BCVA) of the better-seeing eye was analyzed, with visual impairment (VI) defined as BCVA ≥ 20/40. LTL was grouped into quartiles, and its association with BCVA and VI was evaluated after adjusting for covariates.

RESULTS: Among the 4,480 enrolled participants, the weighted means of age, BCVA, and telomere length were 56.1 ± 11.9 years, 0.05 ± 0.08 logMAR, and 5,662 ± 36 base pairs, respectively. The proportion of VI was 2.6%. After adjusting for covariates including sex, ethnicity, education, family poverty income ratio, general health status, hypertension, diabetes, smoking, and body mass index, BCVA was significantly worse in participants with shorter LTL, with a significant trend (p = 0.002). However, after further adjusting for age, the association between LTL and BCVA was no longer significant, without a trend (p = 0.640). No significant association or trend between LTL and VI was found in the stepwise logistic model.

CONCLUSIONS: No age-independent association between LTL and BCVA was found. Our study indicates LTL may not serve as a biomarker for age-related visual acuity decline.

RevDate: 2024-11-11
CmpDate: 2024-11-12

Zeng F, Chen Y, J Lin (2024)

Identification of alternative lengthening of telomeres-related genes prognosis model in hepatocellular carcinoma.

BMC cancer, 24(1):1386.

BACKGROUND: Hepatocellular carcinoma (HCC) is a common malignant tumor worldwide, characterized by high mortality. This study aimed to explore the prognostic value and function of alternative lengthening of telomeres (ALT)-related genes in HCC.

METHODS: Differentially expressed genes (DEGs) were identified based on The Cancer Genome Atlas (TCGA) and then intersected with ALT-related genes to obtain ALTDEGs. Risk score model was constructed using the least absolute shrinkage and selection operator (LASSO) algorithm and Cox regression and validated with Gene Expression Omnibus (GEO) datasets. The predictive efficacy of the risk score and ALTs-score was evaluated by Kaplan-Meier curves, time-ROC curves, and the nomogram analyses. The impacts of SMG5 silencing on the HCC cell behaviors were assessed by CCK-8, wound healing, and Transwell assays.

RESULTS: A total of 500 ALTDEGs were screened and 13 genes (CDCA8, SMG5, RAD54B, FOXD2, NOL10, RRP12, CCT5, CCT4, HDAC1, DDX1, HRG, HDAC2, and PPP1CB) were identified for constructing a prognostic model. The overall survival (OS) curves, time-ROC curves, and nomograms based on the risk score or ALTs-score were developed to optimally predict the survival of HCC patients. ALTs-score was correlated with immune infiltration and confirmed its value in predicting immunotherapy outcomes. Furthermore, RT-qPCR demonstrated that eight risk signature genes were up-regulated in HCC cells. SMG5 silencing suppressed the proliferation, migration, and invasion of HCC cells. It was also found that SMG5 silencing reduced C-circle level in SNU-387 cells.

CONCLUSION: We identified new ALT-related prognostic biomarkers for HCC. SMG5 knockdown inhibited the HCC progression, which might be a promising target for HCC therapy.

RevDate: 2024-11-11
CmpDate: 2024-11-12

Kezer CA, Kusztos V, Kassmeyer B, et al (2024)

Impact of sociodemographic disparities on sarcopenia, telomere length, and mortality in patients with liver disease in the US population.

BMC gastroenterology, 24(1):404.

BACKGROUND & AIMS: Sarcopenia is common in patients with liver disease and both sarcopenia and short telomeres are associated with mortality, however their relationship in patients with liver disease remains unknown.

METHODS: A cohort of 16,072 adults from the National Health and Nutrition Examination Survey from 1999 to 2006 was analyzed. Liver disease was defined by aminotransferases and classified into etiology-based categories. Sarcopenia was defined by dual-energy x-ray absorptiometry. All analyses were conducted separately on each multiple imputation data set and combined via Rubin's rules. P-values for group comparisons were calculated by testing logistic regression parameter estimates. Cox proportional hazards regression was used for mortality analysis with mortality data available until 2015.

RESULTS: Sarcopenia was present in 9.5% of patients with liver disease. Age, race, income, education, physical inactivity, and certain medical comorbidities were associated with sarcopenia. Patients with liver disease and sarcopenia had significantly shorter telomeres than patients with liver disease without sarcopenia when unadjusted for age. The interaction between telomere length and sarcopenia was significantly associated with all-cause mortality.

CONCLUSIONS: The implications of telomere length on all-cause mortality in patients with liver disease varied by age and sarcopenia status. Shorter telomeres appear to be more highly associated with increased mortality in older patients without sarcopenia.

RevDate: 2024-11-11

Giaccherini M, Clay-Gilmour AI, Liotti R, et al (2024)

Genetically determined telomere length in monoclonal gammopathy of undetermined significance, multiple myeloma risk and outcome.

Blood cancer journal, 14(1):200.

RevDate: 2024-11-11
CmpDate: 2024-11-11

Zhang H, Kerr C, Audry J, et al (2025)

A Rapidly Inducible DNA Double-Strand Break to Monitor Telomere Formation, DNA Repair, and Checkpoint Activation.

Methods in molecular biology (Clifton, N.J.), 2862:209-221.

The study of processes that govern genome integrity has been augmented by the ability to create a precise DNA double-strand break (DSB) in a short period of time that allows the kinetics of DNA metabolism and protein recruitment to be followed. Defined DSBs are made by expressing endonucleases with long recognition sites that are rare or absent in the genome, and require that the endonuclease is only active when induced. Research in this area in Schizosaccharomyces pombe was limited because rapidly inducible promoters were not available until around 2005, and several rapidly inducible DSB systems are now available. Here, we describe a system to rapidly induce a modified I-SceI endonuclease that can generate a DSB 20 min after induction. I-SceI has no recognition sites in the S. pombe genome, allowing the introduction of complex substrates to monitor the effects of a new DSB in real time. This chapter describes how I-SceI can be most efficiently induced and a simple cell length measurement assay to monitor cell cycle checkpoint activation from a single DSB.

RevDate: 2024-11-11

Blanchard M, Lin J, Hurley S, et al (2024)

Telomere length and chronotype among women in the California Teachers Study (CTS).

Chronobiology international [Epub ahead of print].

While links between certain chronotypes and poorer health outcomes have been well established in previous studies, few studies have examined the relationship between chronotype and cellular aging. Using data from the California Teachers Study (CTS), the present study evaluates the relationship between cellular aging and chronobiology through an analysis of leukocyte telomere length (LTL) and chronotype among 817 predominantly postmenopausal women with no history of cancer and occupations not associated with night-shift work. Unconditional logistic regression models were run to estimate odds ratios (ORs) for each chronotype category, adjusted for age, ethnicity, and smoking status. Analyses were then stratified by potential modifiers to assess whether results varied among specific subgroups within the sample. Women who reported being current evening types and evening types from teen years to now were significantly less likely to have short LTL compared to women who reported being current morning types or morning types from teen years to now (OR = 0.72; 95% CI = 0.53-0.98; OR = 0.57; 95% CI = 0.39-0.84). Our results suggest that women with no history of cancer who identify as evening chronotypes may undergo decreased cellular aging compared to women in the same population who identify as morning types. Further studies on populations of postmenopausal women are warranted.

RevDate: 2024-11-11

Qi X, Gao L, L Qi (2024)

Genetic Determinants of Telomere Length and Risk of Aneurysmal Subarachnoid Hemorrhage: A Bidirectional Two-Sample Mendelian Randomization Study.

The International journal of neuroscience [Epub ahead of print].

BACKGROUND: Our objective is to investigate the potential causal relationship between telomere length (TL) and aneurysmal subarachnoid hemorrhage (aSAH) and intracranial aneurysms (IAs) by conducting a bidirectional two-sample Mendelian Randomization (MR) study.

METHODS: We utilized publicly available summary data from genome-wide association studies (GWAS) for comprehensive analysis. Telomere length-associated data were sourced from the Epidemiology Unit (IEU) GWAS database (n = 472,174), while data pertaining to intracranial aneurysms were derived from a GWAS meta-analysis conducted by Bakker et al, encompassing aneurysmal subtypes including aSAH (n = 77,074), IAs (n = 79,429), and unruptured intracranial aneurysms (uIA) (n = 74,004), all sampled from European populations. The primary method for MR analysis employed was the Inverse Variance Weighted (IVW) method. Additionally, we conducted various sensitivity analyses to assess the heterogeneity and pleiotropy of study findings. Reverse MR analysis was employed to explore potential reverse causality.

RESULTS: In the forward MR analysis, the IVW method indicated a negative association between TL and aSAH (OR = 0.636, 95% CI: 0.459-0.883, p = 0.006) as well as IAs (OR = 0.670, 95% CI: 0.499-0.900, p = 0.0079). There was no evidence of heterogeneity or horizontal pleiotropy in the forward MR analysis. Reverse MR analysis did not reveal any causal relationship between aSAH, IAs, uIA and TL.

CONCLUSIONS: In European populations, there exists a causal relationship between longer TL and reduced risks of aSAH and IAs Further research is warranted to elucidate the underlying mechanisms and the potential of TL as an intervention target for lowering the incidence of aSAH and IAs.

RevDate: 2024-11-10

Heaphy CM, Patel S, Smith K, et al (2024)

Detection of Alternative Lengthening of Telomeres via Chromogenic in situ Hybridization (ALT-CISH) for the Prognostication of PanNETs and Other Neoplasms.

Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc pii:S0893-3952(24)00231-X [Epub ahead of print].

Molecular studies have shown ALT to be an important prognostic biomarker of shorter relapse-free survival (RFS) for patients with pancreatic neuroendocrine tumors (PanNETs) and other neoplasms. However, the preferred method of detecting ALT in tissue is by fluorescence in situ hybridization (FISH), which has several clinical limitations. These issues necessitate the creation of a chromogenic ALT assay that can be easily implemented into routine practice. A CISH assay was developed using genetically modified osteosarcoma cell lines, 20 normal pancreata, 20 ALT-positive PanNETs, and 20 ALT-negative PanNETs. Thereafter, it was validated on a multi-institutional cohort of 360 surgically resected PanNETs and correlated with multiple clinicopathologic features, RFS, and FISH results. Separately, 109 leiomyosarcomas (LMS) were evaluated by both CISH and FISH, and, similarly, the prognostic significance of ALT status was assessed. Upon optimization, ALT-CISH was identified in 112 of 360 (31%) primary PanNETs and was 100% concordant with FISH testing. ALT correlated with several adverse prognostic findings and distant metastasis (all p<0.004). The 5-year RFS for patients with ALT-positive PanNETs was 35% as compared to 94% for ALT-negative PanNETs. By multivariate analysis, ALT was an independent prognostic factor for shorter RFS. Similarly, ALT was associated with shorter RFS in LMS patients and, analogous to PanNETs, a negative, independent prognostic factor. ALT-CISH was developed and validated in not only PanNETs, but also sarcomas, specifically LMS. CISH testing has multiple advantages over FISH that facilitate its widespread clinical use in the detection of ALT and prognostication of patients with diverse neoplasms.

RevDate: 2024-11-09

Mostovoy Y, Boone PM, Huang Y, et al (2024)

Resolution of ring chromosomes, Robertsonian translocations, and complex structural variants from long-read sequencing and telomere-to-telomere assembly.

American journal of human genetics pii:S0002-9297(24)00375-6 [Epub ahead of print].

Delineation of structural variants (SVs) at sequence resolution in highly repetitive genomic regions has long been intractable. The sequence properties, origins, and functional effects of classes of genomic rearrangements such as ring chromosomes and Robertsonian translocations thus remain unknown. To resolve these complex structures, we leveraged several recent milestones in the field, including (1) the emergence of long-read sequencing, (2) the gapless telomere-to-telomere (T2T) assembly, and (3) a tool (BigClipper) to discover chromosomal rearrangements from long reads. We applied these technologies across 13 cases with ring chromosomes, Robertsonian translocations, and complex SVs that were unresolved by short reads, followed by validation using optical genome mapping (OGM). Our analyses resolved 10 of 13 cases, including a Robertsonian translocation and all ring chromosomes. Multiple breakpoints were localized to genomic regions previously recalcitrant to sequencing such as acrocentric p-arms, ribosomal DNA arrays, and telomeric repeats, and involved complex structures such as a deletion-inversion and interchromosomal dispersed duplications. We further performed methylation profiling from long-read data to discover phased differential methylation in a gene promoter proximal to a ring fusion, suggesting a long-range position effect (LRPE) with heterochromatin spreading. Breakpoint sequences suggested mechanisms of SV formation such as microhomology-mediated and non-homologous end-joining, as well as non-allelic homologous recombination. These methods provide some of the first glimpses into the sequence resolution of Robertsonian translocations and illuminate the structural diversity of ring chromosomes and complex chromosomal rearrangements with implications for genome biology, prediction of LRPEs from integrated multi-omics technologies, and molecular diagnostics in rare disease cases.

RevDate: 2024-11-07

Song B, Lou J, Mu L, et al (2024)

An Innovative Telomere-associated Prognosis Model in AML: Predicting Immune Infiltration and Treatment Responsiveness.

Current medicinal chemistry pii:CMC-EPUB-144408 [Epub ahead of print].

AIMS: To build an innovative telomere-associated scoring model to predict prognosis and treatment responsiveness in acute myeloid leukemia (AML).

BACKGROUND: AML is a highly heterogeneous malignant hematologic disorder with a poor prognosis. While telomere maintenance is frequently observed in tumors, investigations into telomere-related genes (TRGs) in AML remain limited.

OBJECTIVES: This study aimed to identify prognostic TRGs using the least absolute shrinkage and selection operator (LASSO) Cox regression and multivariate Cox regression, evaluate their predictive value, explore the association between TRG scores and immune cell infiltration, and assess the sensitivity of high-scoring AML patients to chemotherapeutic agents.

METHOD: Univariate Cox regression analysis was conducted on the TCGA cohort to identify prognostic TRGs and to develop the TRG scoring model using LASSO-Cox and multivariate Cox regression. Validation was performed on the GSE37642 cohort. Immune cell infiltration patterns were assessed through computational analysis, and the sensitivity to chemotherapeutic agents was evaluated.

RESULTS: Thirteen prognostic TRGs were identified, and a seven-TRG scoring model (including NOP10, OBFC1, PINX1, RPA2, SMG5, MAPKAPK5, and SMN1) was developed. Higher TRG scores were associated with a poorer prognosis, as confirmed in the GSE37642 cohort, and remained an independent prognostic factor even after adjusting for other clinical characteristics. The high-score group was characterized by elevated infiltration of B cells, T helper cells, natural killer cells, tumor-infiltrating lymphocytes, regulatory T (Treg) cells, M2 macrophages, neutrophils, and monocytes, along with reduced infiltration of gamma delta T cells, CD4- T cells, and resting mast cells. Moreover, high infiltration of M2 macrophages and Tregs was associated with poor overall survival compared to low infiltration. Notably, high-risk AML patients were resistant to Erlotinib, Parthenolide, and Nutlin-3a, but sensitive to AC220, Midostaurin, and Tipifarnib. Additionally, using RT-qPCR, we observed significantly higher expression of two model genes, OBFC1 and SMN1, in AML tissues compared to control tissues.

CONCLUSION: This innovative TRG scoring model demonstrates considerable predictive value for AML patient prognosis, offering valuable insights for optimizing treatment strategies and personalized medicine approaches. The identified TRGs and associated scoring models could aid in risk stratification and guide tailored therapeutic interventions in AML patients.

RevDate: 2024-11-06

Allsopp RC, Hernández LM, MK Taylor (2024)

The Val66Met variant of brain-derived neurotrophic factor is linked to reduced telomere length in a military population: a pilot study.

Scientific reports, 14(1):27013.

In military populations, gene-environment interactions can influence performance and health outcomes. Brain-derived neurotrophic factor (BDNF) is a central nervous system protein that is important for neuronal function and synaptic plasticity. A BDNF single nucleotide polymorphism, rs6265, leads to an amino acid substitution of valine (Val) with methionine (Met) at codon 66 (Val66Met), which may influence an individual's response to occupational stress, and predispose military members to psychological disorders. Telomere length (TL), a novel measure of biological aging, can be used as a biomarker of stress. Accordingly, telomere shortening may be a surrogate indicator of physiological weathering due to chronic disease and stressful life events. To increase our understanding about the potential effect of the Val66Met mutation on the human stress response, we evaluated the relationships between Val66Met, TL, and mental health symptoms in a military population. In this pilot study (N = 164), we observed an association between Val66Met and reduced TL (p = 0.048). There was no relationship between Val66Met and mental health symptoms. These results support the investigation of gene-environment interactions, and their potential influence on TL due to occupational stress such as military service.

RevDate: 2024-11-06
CmpDate: 2024-11-06

Yılmaz ŞG, H Bozkurt (2024)

The expression of shelterin genes and telomere repeat analysis and their effect on Alzheimer's disease.

Molecular biology reports, 51(1):1124.

BACKGROUND: Alzheimer's disease (AD) is an age-related dementia disorder characterized by memory loss and behavioral changes. Maintaining the integrity of telomere shortening in AD is important for cellular survival and homeostasis in all cells, especially glial cells. The shelterin protein complex provides telomere integrity. Measuring the expression levels of shelterin genes and determining the telomere lengths regulated by this complex will reveal their effects on AD progression and adult neurogenesis and will allow the detection of the disease or the determination of the progression process from an accessible tissue.

METHODS AND RESULTS: The study population included 111 patients and 91 healthy controls (male and female, < 50 age). The clinical histories (age, gender, hypertension, diabetes mellitus, obesity, cardiovascular disease, MMSE, medication use, family history, sleep disorders, seizure), covariates (HGB, ESR, Na, P, Cl, BUN, CRP, B12, TSH, Glucose, and MRI findings) and the expressional changes of shelterin genes (TERF1, TERF2, TINF2, POT1, TPP1, and RAP1) between the patient and control groups were evaluated relatively. ROC analyses determined the diagnostic power of telomere repeats and gene expressions.

CONCLUSIONS: In conclusion, upregulation of expression of shleterin complex genes was detected in AD, where telomeres are significantly shorter than in controls (P < 0.05). However, only TERF2 and RAP1 were significant (P < 0.05). A positive relationship was detected between telomere repeats and these genes (P < 0.05). Telomere repeats may be a strong diagnostic criterion to distinguish AD individuals from healthy individuals (AUC = 1.000). The upregulation of TERF2 and RAP1 core genes required for telomere integrity results in the instability of excessively shortened telomeres. Expression silencing of these genes may increase telomerase activity and maintain cellular survival. Also, the detection of telomere repeats has potential in the early diagnosis of AD patients.

RevDate: 2024-11-06

Gao B, Sun PC, Song YC, et al (2024)

A telomere-to-telomere genome assembly of Salix cheilophila reveals its evolutionary signatures for environmental adaptation.

Plant communications pii:S2590-3462(24)00598-4 [Epub ahead of print].

RevDate: 2024-11-05

Billing D, A Sfeir (2024)

The Role of Microhomology-Mediated End Joining (MMEJ) at Dysfunctional Telomeres.

Cold Spring Harbor perspectives in biology pii:cshperspect.a041687 [Epub ahead of print].

DNA double-strand break (DSB) repair pathways are crucial for maintaining genome stability and cell viability. However, these pathways can mistakenly recognize chromosome ends as DNA breaks, leading to adverse outcomes such as telomere fusions and malignant transformation. The shelterin complex protects telomeres from activation of DNA repair pathways by inhibiting nonhomologous end joining (NHEJ), homologous recombination (HR), and microhomology-mediated end joining (MMEJ). The focus of this paper is on MMEJ, an error-prone DSB repair pathway characterized by short insertions and deletions flanked by sequence homology. MMEJ is critical in mediating telomere fusions in cells lacking the shelterin complex and at critically short telomeres. Furthermore, studies suggest that MMEJ is the preferred pathway for repairing intratelomeric DSBs and facilitates escape from telomere crisis. Targeting MMEJ to prevent telomere fusions in hematologic malignancies is of potential therapeutic value.

RevDate: 2024-11-05

O'Sullivan RJ, RA Greenberg (2024)

Mechanisms of Alternative Lengthening of Telomeres.

Cold Spring Harbor perspectives in biology pii:cshperspect.a041690 [Epub ahead of print].

In recent years, significant advances have been made in understanding the intricate details of the mechanisms underlying alternative lengthening of telomeres (ALT). Studies of a specialized DNA strand break repair mechanism, known as break-induced replication, and the advent of telomere-specific DNA damaging strategies and proteomic methodologies to profile the ribonucleoprotein composition of telomeres enabled the discovery of networks of proteins that coordinate the stepwise homology-directed DNA repair and DNA synthesis processes of ALT. These networks couple mediators of homologous recombination, DNA template-switching, long-range template-directed DNA synthesis, and DNA strand resolution with SUMO-dependent liquid condensate formation to create discrete nuclear bodies where telomere extension occurs. This review will discuss the recent findings of how these networks may cooperate to mediate telomere extension by the ALT mechanism and their impact on telomere function and integrity in ALT cancer cells.

RevDate: 2024-11-05
CmpDate: 2024-11-05

Burraco P, Gabor C, Bryant A, et al (2024)

Ionizing radiation has negligible effects on the age, telomere length and corticosterone levels of Chornobyl tree frogs.

Biology letters, 20(11):20240287.

The accident that occurred at the Chornobyl nuclear power plant (Ukraine, 1986) contaminated a large extension of territory after the deposition of radioactive material. It is still under debate whether the chronic exposure to the radiation levels currently present in the area has long-term effects on organisms, such as decreases in longevity. Here, we investigate whether current levels of radiation in Chornobyl negatively impact the age of the Eastern tree frog Hyla orientalis. We also explore whether radiation induces changes in an ageing marker, telomere length or the stress hormone corticosterone. We found no effect of total individual absorbed radiation (including both external and internal exposure) on frog age (n = 197 individuals sampled in 3 consecutive years). We also did not find any relationship between individual absorbed radiation and telomere length, nor between individual absorbed radiation and corticosterone levels. Our results suggest that radiation levels currently experienced by Chornobyl tree frogs may not be high enough to cause severe chronic damage to semi-aquatic vertebrates such as this species. This is the first study addressing age and stress hormones in Chornobyl wildlife, and thus future research will confirm if these results can be extended to other taxa.

RevDate: 2024-11-05
CmpDate: 2024-11-05

Rodrigues P, Furtado G, Martins M, et al (2024)

Exposing telomere length's impact on malnutrition risk among older adults residing in the community: Insights from cross-sectional data analysis.

PloS one, 19(11):e0308612 pii:PONE-D-23-39724.

BACKGROUND: Successful aging is associated with an increase in life expectancy. For a better understanding of the aging process, recognize the relationship between telomere length and nutritional status is a novel approach in geriatric science. Telomers shortening coincides with a decrease in life expectancy, and an increased risk of malnutrition-related diseases.

GOALS: The goal of this study was to investigate whether a shorter telomere length is associated with a greater likelihood of malnutrition in community-dwelling older adults.

METHODS: A cross-sectional study with a probabilistic sample of 448 older people aged 60 years old or over, and living in the urban area of an inland Brazilian municipality was conducted. The information was gathered in two stages: a) a personal interview was conducted to obtain sociodemographic, cognitive, and functional autonomy data. The Mini Nutritional Assessment was used to assess the risk of malnutrition. b) a blood sample was taken to proceed with the relative quantitative study of telomere length using real-time qPCR method. The differences between the groups were estimated using Pearson's v2 and Fisher's exact tests. In the data analysis, descriptive statistics and multiple logistic regression were applied.

RESULTS: In 34.15% of the total sample, malnutrition was recognized as a risk factor. Older people with the shortest telomere length had more chances of getting malnutrition (OR = 1.63; IC:95% = 1.04-2.55) compared to those with longer telomeres, independent of age groups, family income, multimorbidity, cognitive decline, and depressive symptoms.

CONCLUSION: The creation of clinical trials and the implementation of therapies to reduce the risk of malnutrition will be aided using the telomere length as an aging innovative biomarker, connected with nutritional status.

RevDate: 2024-11-04

Mao H, Lin T, Huang S, et al (2024)

Association between monocyte to high-density lipoprotein cholesterol ratio and telomere length: based on NHANES 1999-2002.

BMC cardiovascular disorders, 24(1):616.

BACKGROUND: Telomere length is closely associated with the occurrence and development of cardiovascular and other diseases. Monocyte to high-density lipoprotein cholesterol ratio (MHR) is a novel indicator of inflammation, oxidative stress, and metabolic syndrome, with some predictive ability for related disease risks in clinical practice. However, there is no research on the correlation between these two factors.

METHODS: Using data from the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2002, we conducted analysis and research on the correlation between MHR and telomere length using the Kruskal-Wallis H test, Spearman rank correlation analysis, and partial correlation analysis. Weighted linear regression analysis assessed the strength of the association between the two variables, while restricted cubic spline regression (RCS) explored potential nonlinear relationships between them.

RESULTS: The results of correlation analysis showed that MHR levels were negatively correlated with telomere length (ρ=-0.083, P < 0.001), and this relationship remained statistically significant after controlling for other covariates (P all < 0.001). Weighted linear regression analysis showed that after adjusting for all covariates, MHR remained negatively associated with telomere length (β = -0.020; 95% CI: -0.039 to -0.002; P = 0.037). Subgroup analysis shows that the negative association between MHR and telomere length appeared more striking among females (𝛽 = -0.024; 95%CI: -0.050 to 0.001; P = 0.058), the Non-Hispanic White (𝛽 = -0.022; 95%CI: -0.045 to 0.002; P = 0.066), and other race (𝛽 = -0.067; 95%CI: -0.134 to -0.000; P = 0.049). Using RCS explored potential nonlinear relationships between MHR and telomere length, revealing no nonlinear relationship between the two (P = 0.102).

CONCLUSIONS: This study suggests a negative correlation between MHR levels and telomere length in American adults. More comprehensive research is needed to confirm these findings in the future.

RevDate: 2024-11-04

Herrera-Moyano E, Porreca RM, Ranjha L, et al (2024)

Human SKI component SKIV2L regulates telomeric DNA-RNA hybrids and prevents telomere fragility.

iScience, 27(11):111096.

Super killer (SKI) complex is a well-known cytoplasmic 3'-5' mRNA decay complex that functions with the exosome to degrade excessive and aberrant mRNAs, is implicated with the extraction of mRNA at stalled ribosomes, tackling aberrant translation. Here, we show that SKIV2L and TTC37 of the hSKI complex are present within the nucleus, localize on chromatin and at some telomeres during the G2 cell cycle phase. In cells, SKIV2L prevents telomere replication stress, independently of its helicase domain, and increases the stability of telomere DNA-RNA hybrids in G2. We further demonstrate that purified hSKI complex binds telomeric DNA and RNA substrates in vitro and SKIV2L association with telomeres is dependent on DNA-RNA hybrids. Taken together, our results provide a nuclear function for SKIV2L of the hSKI complex in overcoming replication stress at telomeres mediated by its recruitment to DNA-RNA hybrid structures in G2 and thus maintaining telomere stability.

RevDate: 2024-11-04

Zhao W, Wu J, Tian M, et al (2024)

Characterization of O-methyltransferases in the biosynthesis of phenylphenalenone phytoalexins based on the telomere-to-telomere gapless genome of Musella lasiocarpa.

Horticulture research, 11(4):uhae042.

Phenylphenalenones (PhPNs), phytoalexins in wild bananas (Musaceae), are known to act against various pathogens. However, the abundance of PhPNs in many Musaceae plants of economic importance is low. Knowledge of the biosynthesis of PhPNs and the application of biosynthetic approaches to improve their yield is vital for fighting banana diseases. However, the processes of PhPN biosynthesis, especially those involved in methylation modification, remain unclear. Musella lasiocarpa is a herbaceous plant belonging to Musaceae, and due to the abundant PhPNs, their biosynthesis in M. lasiocarpa has been the subject of much attention. In this study, we assembled a telomere-to-telomere gapless genome of M. lasiocarpa as the reference, and further integrated transcriptomic and metabolomic data to mine the candidate genes involved in PhPN biosynthesis. To elucidate the diversity of PhPNs in M. lasiocarpa, three screened O-methyltransferases (Ml01G0494, Ml04G2958, and Ml08G0855) by phylogenetic and expressional clues were subjected to in vitro enzymatic assays. The results show that the three were all novel O-methyltransferases involved in the biosynthesis of PhPN phytoalexins, among which Ml08G0855 was proved to function as a multifunctional enzyme targeting multiple hydroxyl groups in PhPN structure. Moreover, we tested the antifungal activity of PhPNs against Fusarium oxysporum and found that the methylated modification of PhPNs enhanced their antifungal activity. These findings provide valuable genetic resources in banana breeding and lay a foundation for improving disease resistance through molecular breeding.

RevDate: 2024-11-04

Zhou F, Sun Z, Cheng L, et al (2024)

Leptin modulates ovarian granulosa cell apoptosis by regulating telomerase activity and telomere length in polycystic ovary syndrome.

Laboratory investigation; a journal of technical methods and pathology pii:S0023-6837(24)01847-6 [Epub ahead of print].

Leptin (LEP) is implicated in the pathogenesis of polycystic ovary syndrome (PCOS). This study investigates the mechanism of LEP in PCOS. The baseline information of 80 PCOS patients and matched controls was analyzed, with serum and follicular fluid (FF) LEP and LEP receptor (LEPR) levels, telomerase activity, and relative telomere length (TL) measured. The correlation of FF LEP with telomerase activity and TL was analyzed. The viability and apoptosis of KGN cells (the ovarian granulosa cells) treated with gradient LEP were assessed. LEP-LEPR interaction was examined. LEPR, c-MYC, and TERT levels and c-MYC protein expression in the TERT promoter region were determined. Nuclear c-MYC translocation was detected. LEP was upregulated in sera and FF of PCOS patients. FF LEP positively-correlated with telomerase activity and TL. Low-concentration LEP facilitated KGN cell proliferation and high-concentration LEP dose-dependently suppressed cell proliferation, promoted apoptosis, upregulated LEPR and increased telomerase activity and relative TL. LEP-LEPR interaction upregulated c-MYC and facilitated its nuclear accumulation. c-MYC enrichment in the TERT promoter region upregulated TERT, altering telomerase activity and TL and inducing cell apoptosis. Briefly, LEP/LEPR activate c-MYC, modulate TERT expression, and increase telomerase activity and TL, thus inducing ovarian granulosa cell apoptosis and participating in PCOS.

RevDate: 2024-11-03
CmpDate: 2024-11-03

Trachu N, Reungwetwattana T, Meanwatthana J, et al (2024)

Leukocytes telomere length as a biomarker of adverse drug reactions induced by Osimertinib in advanced non-small cell lung cancer.

Scientific reports, 14(1):26543.

This study aimed to measure relative telomere length (RTL) in blood leukocytes of advanced-stage NSCLC patients either with or without Osimertinib-induced ADRs and determine whether RTL could serve as a biomarker of Osimertinib-induced ADRs. Blood leukocytes RTL were measured in 63 advanced-stage NSCLC patients and 62 age-matched healthy controls using real-time polymerase chain reaction. In patients with advanced-stage NSCLC, RTL was significantly shorter than that in healthy controls (P < 0.001). Compared to patients without ADRs and those with mild/moderate ADRs, patients with severe ADRs exhibited significantly decreased RTL (P < 0.001, P < 0.001, respectively). ROC curve analysis uncovered a diagnostic value of RTL as a biomarker of Osimertinib-induced ADRs (AUC = 1.000, P < 0.001). Kaplan-Meier analysis revealed a significant association between shorter RTL and increased cumulative incidence of Osimertinib-induced ADRs in patients with advanced-stage NSCLC (P < 0.001). Shorter RTL in blood leukocytes would reflect the occurrence of Osimertinib-induced ADRs and might emerge as a promising biomarker for identifying advanced-stage NSCLC patients who are at risk of experiencing Osimertinib-induced ADRs, particularly those with severe ADRs.

RevDate: 2024-11-01
CmpDate: 2024-11-01

Hu J, Zhang J, Liu Y, et al (2024)

Causal linkage of Graves' disease with aging: Mendelian randomization analysis of telomere length and age-related phenotypes.

BMC geriatrics, 24(1):901.

BACKGROUND: Aging is an irreversible progressive decline in physical function. Graves' disease (GD) is a common cause of hyperthyroidism and is characterized by elevated levels of the thyroid hormone (TH). High TH levels are associated with aging and a shortened lifespan. The causal relationship between GD and aging has yet to be investigated.

METHODS: We used genome-wide association study (GWAS) datasets and Mendelian randomization (MR) analysis to explore the causal link between GD and aging. To assess the statistical power of instrumental variables (IVs), F-statistics and R[2] were used. MR analysis was conducted using inverse-variance weighting (IVW), MR-Egger, weighted median, and weighted mode. The odds ratio (OR) and 95% CI were calculated to estimate the relative risk of GD to the outcomes. The Cochran Q test, I[2], MR-PRESSO test, and MR-Egger regression intercept were calculated using statistical and leave-one-out analyses to test the heterogeneity, horizontal pleiotropy, and stability of the IVs on the outcomes.

RESULTS: F-statistics of the five IVs were greater than 10, and the R[2] values ranged from 0.033 to 0.156 (R[2] > 0.01). According to the results of the IVW analysis, GD had no causal effect on facial aging (p = 0.189), age-related macular degeneration (p = 0.346), and Alzheimer's disease (p = 0.479). There was a causal effect of GD on the remaining outcomes: telomere length (TL) (OR = 0.982; 95%CI:0.969-0.994; p = 0.004), senile cataract (OR = 1.031; 95%CI:1.002-1.060; p = 0.033), age-related hearing impairment (OR = 1.009; 95%CI:1.004-1.014; p = 0.001), chronic obstructive pulmonary disease (COPD) (OR = 1.055; 95%CI:1.008-1.103; p = 0.020), and sarcopenia (OR = 1.027; 95%CI:1.009-1.046; p = 0.004).

CONCLUSIONS: GD accelerates the occurrence of age-related phenotypes including TL, senile cataracts, age-related hearing impairment, COPD, and sarcopenia. In contrast, there are no causal linkages between GD and facial aging, age-related macular degeneration, or Alzheimer's disease. Further experimental studies could be conducted to elucidate the mechanisms by which GD facilitates aging, which could help slow down the progress of aging.

RevDate: 2024-11-01

Harman A, TM Bryan (2024)

Telomere maintenance and the DNA damage response: a paradoxical alliance.

Frontiers in cell and developmental biology, 12:1472906.

Telomeres are the protective caps at the ends of linear chromosomes of eukaryotic organisms. Telomere binding proteins, including the six components of the complex known as shelterin, mediate the protective function of telomeres. They do this by suppressing many arms of the canonical DNA damage response, thereby preventing inappropriate fusion, resection and recombination of telomeres. One way this is achieved is by facilitation of DNA replication through telomeres, thus protecting against a "replication stress" response and activation of the master kinase ATR. On the other hand, DNA damage responses, including replication stress and ATR, serve a positive role at telomeres, acting as a trigger for recruitment of the telomere-elongating enzyme telomerase to counteract telomere loss. We postulate that repression of telomeric replication stress is a shared mechanism of control of telomerase recruitment and telomere length, common to several core telomere binding proteins including TRF1, POT1 and CTC1. The mechanisms by which replication stress and ATR cause recruitment of telomerase are not fully elucidated, but involve formation of nuclear actin filaments that serve as anchors for stressed telomeres. Perturbed control of telomeric replication stress by mutations in core telomere binding proteins can therefore cause the deregulation of telomere length control characteristic of diseases such as cancer and telomere biology disorders.

RevDate: 2024-11-01

Themoteo RM, De Paula VJR, Rocha NKR, et al (2023)

Lithium Prevents Telomere Shortening in Cortical Neurons in Amyloid-Beta Induced Toxicity.

NeuroSci, 4(1):1-8.

BACKGROUND: There is consistent evidence of the potential benefits of lithium attenuating mechanisms of neurodegeneration, including those related to the pathophysiology of Alzheimer's disease (AD), and facilitating neurotrophic and protective responses, including maintenance of telomere length. The aim was to investigate the protective effect of the pre-treatment with lithium on amyloid-beta (Aβ)-induced toxicity and telomere length in neurons.

METHODS: Cortical neurons were treated with lithium chloride at therapeutic and subtherapeutic concentrations (2 mM, 0.2 mM and 0.02 mM) for seven days. Amyloid toxicity was induced 24 h before the end of lithium treatment.

RESULTS: Lithium resulted in 120% (2 mM), 180% (0.2 mM) and 140% (0.02 mM) increments in telomere length as compared to untreated controls. Incubation with Aβ1-42 was associated with significant reductions in MTT uptake (33%) and telomere length (83%) as compared to controls.

CONCLUSIONS: Lithium prevented loss of culture viability and telomere shortening in neuronal cultures challenged with Aβ fibrils.

RevDate: 2024-10-31

Chuang LC (2024)

Which one occurs first?Telomere length (TL) shortening or PCOS?.

Taiwanese journal of obstetrics & gynecology, 63(6):967.

RevDate: 2024-10-30

Ye Q, Apsley AT, Hastings WJ, et al (2024)

Parental age at birth, telomere length, and autism spectrum disorders in the UK Biobank cohort.

Autism research : official journal of the International Society for Autism Research [Epub ahead of print].

Older parental age at birth is associated with increased risk of autism spectrum disorders (ASD) in offspring. Independently, shorter telomere length (TL) has also been shown to be associated with ASD in children. However, older paternal age at birth, with or without controlling for maternal age, has been associated with longer TL, a seemingly contradictory finding. Here, we conducted a retrospective cohort study among participants in the UK Biobank to disentangle associations between leukocyte TL and ASD status in adults, and the potential moderation by parental age on adult offspring's TL. Participants with ASD diagnosis (N = 87) with a mean age of 46.0 (SD 4.4) years were matched to participants without ASD diagnosis (N = 870) based on age, sex, ethnicity, education, household income, and assessment center. No statistically significant differences were seen in TL between participants with and without ASD when parental age at birth was not considered. However, there was a significant interaction between ASD diagnostic status and parental age on participants' TL, such that older paternal or maternal age at birth was more strongly associated with longer TL in participants with ASD. This study suggests that the shortened TL observed in children with ASD in previous research may partially depend on parental age at birth. Future studies tracking TL attrition before ASD diagnosis are warranted to depict temporal associations and the interacting effects of parental age at birth and ASD status on TL across the lifespan.

RevDate: 2024-10-30
CmpDate: 2024-10-30

Bianco-Miotto T, Phillips AL, Heinze DR, et al (2024)

Adverse pregnancy outcomes are associated with shorter telomere length in the 17-year-old child.

Journal of developmental origins of health and disease, 15:e26 pii:S2040174424000291.

This study examined associations between pregnancy and infant birth outcomes with child telomere length at age 17 years; and investigated if there are sex differences between pregnancy complications and telomere length. We utilised the population-based prospective Raine cohort study in Western Australia, Australia. 2900 pregnant women were recruited at 16-20 weeks' gestation (Gen 1), and their children (Gen 2) were followed up over several years. Generalised linear models were used to examine relationships between pregnancy or birth outcomes (gestational diabetes, pre-eclampsia, preterm birth, low birth weight, macrosomia), and as a composite, with telomere length, measured via a DNA sample from blood at 17 years of age. Analyses were adjusted for a range of confounders. Among the 1202 included children, there were no differences in child telomere length for any of the individual maternal or birth weight pregnancy outcomes nor were there any significant interactions between each of the complications (individual or composite) and the sex of the child. However, females born from any of the 5 adverse outcomes had shorter telomeres (estimated mean (SE) = -0.159 (0.061), p = 0.010) than females born in the absence of these complications. Specifically, females born from a pre-eclamptic pregnancy had shorter telomeres than females not born from a pre-eclamptic pregnancy (estimated mean (SE) = -0.166 (0.072), p = 0.022). No relationships were observed in males. Further longitudinal studies are needed to understand mediating factors that are important in predicting offspring telomere length and the necessity to investigate females and males independently.

RevDate: 2024-10-30

Fernández de la Puente M, Valle-Hita C, Salas-Huetos A, et al (2024)

Sperm and leukocyte telomere length are related to sperm quality parameters in healthy men from the Led-Fertyl study.

Human reproduction open, 2024(4):hoae062.

STUDY QUESTION: Could sperm and leukocyte telomere length (TL) be associated with sperm quality parameters and reproductive health in men from the general population?

SUMMARY ANSWER: A positive association between sperm and leukocyte TL with sperm concentration and total count has been demonstrated.

WHAT IS KNOWN ALREADY: Male factors account for almost half of cases of couple infertility, and shorter TLs have been observed in sperm from men with impaired sperm parameters. However, evidence in men from the general population is limited.

STUDY DESIGN SIZE DURATION: A total of 200 volunteers of reproductive age were recruited between February 2021 and April 2023 to participate in the Lifestyle and Environmental Determinants of Seminogram and Other Male Fertility-Related Parameters (Led-Fertyl) cross-sectional study.

TLs in sperm and leukocytes were measured using quantitative polymerase chain reaction (qPCR) in 168 and 194 participants, respectively. Sperm parameters, including concentration, total count, motility, vitality, and morphology, were analyzed using a computer-assisted sperm analysis (CASA) SCA[®] system according to the World Health Organization (WHO) 2010 guidelines. Multivariable regression models were performed to assess the associations between sperm and leukocyte TL, either in tertiles or as continuous variables, and sperm quality parameters while adjusting for potential confounders.

Participants in tertiles 2 (T2) and 3 (T3) of sperm TL showed a higher sperm concentration (β: 1.09; 95% CI: 0.09-2.09 and β: 2.06; 95% CI: 1.04-3.09 for T2 and T3, respectively; P-trend < 0.001), compared to those in the reference tertile (T1). Participants in the highest tertile of sperm TL showed higher total sperm count (β: 3.83; 95% CI: 2.08-5.58 for T3 vs T1; P-trend < 0.001). Participants in the top tertile of leukocyte TL showed higher sperm concentration (β: 1.49; 95% CI: 0.44-2.54 for T3 vs T1; P-trend = 0.004), and total count (β: 3.49; 95% CI: 1.62-5.35 for T3 vs T1; P-trend < 0.001) compared with participants in T1. These results remained consistent when sperm and leukocyte TL were modelled as continuous variables.

One limitation is the impossibility of establishing a cause-effect relationship due to the cross-sectional study design. Additionally, the sample size of the study cannot be considered large.

Sperm and leukocyte TLs are associated with sperm quality parameters in the general population. Additional determinations and further studies with larger sample sizes are needed to clarify the mechanisms underlying these associations and to investigate the further implications.

The Led-Fertyl study was supported by the Spanish government's official funding agency for biomedical research, Instituto de Salud Carlos III (ISCIII), through the Fondo de Investigación para la Salud (FIS) and co-funded by the European Union ERDF/ESF, 'A way to make Europe'/'Investing in your future' (PI21/01447), and the Diputació de Tarragona (2021/11-No.Exp. 8004330008-2021-0022642). J.S.-S., senior author of the present study, is partially supported by ICREA under the ICREA Academia program. M.F.d.l.P. was supported by a predoctoral grant from the Rovira i Virgili University and Diputació de Tarragona (2020-PMF-PIPF-8). C.V.-H. received a predoctoral grant from the Generalitat de Catalunya (2022 FI_B100108). M.Á.M. was supported by the Sara Borrell postdoctoral fellowship (CD21/00045-Instituto de Salud Carlos III (ISCIII)). All authors declare that they have no conflicts of interest.

TRIAL REGISTRATION NUMBER: N/A.

RevDate: 2024-10-29
CmpDate: 2024-10-29

Lyu Y, Zhao H, Zeng G, et al (2024)

Mapping the evolving trend of research on leukocyte telomere length: a text-mining study.

Human genomics, 18(1):117.

BACKGROUND: Substantial evidence indicates that measuring leukocyte telomere length (LTL) is a useful tool that may be considered as a valuable biomarker of individual biological age, correlating with numerous chronic disorders. However, to date, there has been a lack of in-depth understanding regarding the current landscape and forthcoming developments in the LTL field. Therefore, this study aimed to utilize bibliometric methods to summarize the knowledge structure, current focus, and emerging directions in this field.

METHOD: Scientific publications on LTL spanning the period from 2000 to 2022 were acquired from the Web of Science Core Collection database. Several bibliometric tools including CiteSpace, VOSviewer, and an online website were utilized for bibliometric analysis. The primary evaluations encompassed investigating the major contributors and their collaborative relationships among countries/regions, institutions, and authors, conducting co-citation analyses of authors, journals, as well as reference, examining reference bursts, as well as performing co-occurrence analyses of keywords.

RESULTS: There are 1818 papers with 66,668 citations identified. Both the annual publication and citation counts on LTL exhibited significant upward trends. The United States emerged as the most prominent contributor, as evidenced by the greatest volume of papers and the highest H-index value. University of California San Francisco and Aviv A were identified as the most productive institution and author in this domain, respectively. Reference analysis revealed that longitudinal study and mendelian randomization study are the most concerned research method in this field recently. Keywords analysis showed that the most concerned diseases in LTL fields were aging, inflammation, cardiovascular diseases, endocrine diseases, neurological and psychiatric diseases, and cancers. In addition, the following research directions such as "COPD", "mendelian randomization", "adiposity", "colorectal cancer", "National Health and Nutrition Examination Survey (NHNES)", "telomerase reverse transcriptase", "pregnancy" have garnered increasing attention in recent times and hold the potential to evolve into research foci in the foreseeable future.

CONCLUSION: This is the first bibliometric study that provides comprehensive overview of LTL research. The findings of this study could become valuable references for investigators to explore and address the current and emerging challenges in LTL research.

RevDate: 2024-10-29

Salgado S, Abreu PL, Moleirinho B, et al (2024)

Human PC4 supports telomere stability and viability in cells utilizing the alternative lengthening of telomeres mechanism.

EMBO reports [Epub ahead of print].

Cancer cells with an activated Alternative Lengthening of Telomeres (ALT) mechanism elongate telomeres via homology-directed repair. Sustained telomeric replication stress is an essential trigger of ALT activity; however, it can lead to cell death if not properly restricted. By analyzing publicly available data from genome-wide CRISPR KO screenings, we have identified the multifunctional protein PC4 as a novel factor essential for ALT cell viability. Depletion of PC4 results in rapid ALT cell death, while telomerase-positive cells show minimal effects. PC4 depletion induces replication stress and telomere fragility primarily in ALT cells, and increases ALT activity. PC4 binds to telomeric DNA in cells, and its binding can be enhanced by telomeric replication stress. Finally, a mutant PC4 with partly impaired single stranded DNA binding activity is capable to localize to telomeres and suppress ALT activity and telomeric replication stress. We propose that PC4 supports ALT cell viability, at least partly, by averting telomere dysfunction. Further studies of PC4 interactions at ALT telomeres may hold promise for innovative therapies to eradicate ALT cancers.

RevDate: 2024-10-28

Alwehaidah MS, M Bakhiet (2024)

Association of leukocyte telomere length and the risk of disease severity and metabolic comorbidities in Arab patients with psoriasis.

Cytogenetic and genome research pii:000542323 [Epub ahead of print].

INTRODUCTION: Several studies have related shortened leukocyte telomere length (LTL) with age-related diseases and worse prognosis. Telomere length attrition has recently been associated with inflammatory diseases, including psoriasis. However, no study has demonstrated an association between LTL and the risk of disease severity and metabolic comorbidities in Arab patients with psoriasis (Ps).

METHODS: 68 Ps and 42 normal controls (NC) were included. LTL and oxidative damage were determined by quantitative (q) PCR. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using logistic regression. Statistical differences between the groups were determined using 2 and t-tests.

RESULTS: Patients with psoriasis had significantly shorter LTL (P= 0.032) and higher oxidative damage (P= 0.015) than those without psoriasis. Patients with moderate-to-severe index (P= 0.03) and metabolic comorbidity showed significantly shorter LTL (P= 0.003) compared to patients with mild index and without metabolic comorbidity, respectively. Patients with short LTL (≤ 0.9) were correlated with higher risk of moderate-to-severe conditions (OR= 6.98, 95% CI= 2.3-20.8, P= 0.001) and metabolic comorbidities (OR= 2.89, 95% CI= 1.02- 8.2, P= 0.04).

CONCLUSION: LTL shortening may be a consequence of increased oxidative damage, and is related to the risk of severe psoriasis and metabolic comorbidities. Therefore, LTL may be a good candidate biomarker for predicting the risk of poor prognosis in patients with psoriasis.

RevDate: 2024-10-28

McLester-Davis LWY, Norton D, Papale LA, et al (2024)

Telomere length and cognitive function among middle-aged and older participants from communities underrepresented in aging research: A preliminary study.

bioRxiv : the preprint server for biology pii:2024.10.14.618331.

OBJECTIVE: Accelerated biological aging is a plausible and modifiable determinant of dementia burden facing minoritized communities, but is not well-studied in these historically underrepresented populations. Our objective was to preliminarily characterize relationships between telomere length and cognitive health among American Indian/Alaska Native (AI/AN) and Black/African American (B/AA) middle-aged and older adults.

METHODS: This study included data on telomere length and cognitive test performance from 187 participants, enrolled in one of two community-based cognitive aging cohorts and who identified their primary race as AI/AN or B/AA.

RESULTS: Nested multivariable regression models revealed preliminary evidence for associations between telomere length and cognitive performance, and these associations were partially independent of chronological age.

DISCUSSION: Small sample size limited estimate precision, however, findings suggest future work on telomere length and cognitive health in underrepresented populations at high risk for dementia is feasible and valuable as a foundation for social and behavioral intervention research.

RevDate: 2024-10-28

Kim D, Bhargava R, Wang SC, et al (2024)

TRIM24 directs replicative stress responses to maintain ALT telomeres via chromatin signaling.

bioRxiv : the preprint server for biology pii:2024.10.18.618947.

An inability to replicate the genome can cause replication stress and genome instability. Here, we develop BLOCK-ID, a proteomic method to identify and visualize proteins at stressed replication forks. This approach successfully identified novel mediators of the replication stress response, including the chromatin acetylation reader protein TRIM24. In validating TRIM24 function, we uncovered its crucial role in coordinating Alternative Lengthening of Telomeres (ALT), a cancer-specific telomere extension pathway involving replication stress. Our data reveal that TRIM24 is directed to telomeres via a p300/CBP-dependent acetylation chromatin signaling cascade, where it organizes ALT-associated PML bodies (APBs) to promote telomere DNA synthesis. Strikingly, we demonstrate that when artificially tethered at telomeres, TRIM24 can stimulate new telomere DNA synthesis in a SUMO-dependent manner, independently of p300/CBP or PML-dependent APBs. Thus, this study identifies a TRIM24 chromatin signaling pathway required for ALT telomere maintenance.

RevDate: 2024-10-28

Rodriguez MD, Bailey SM, Doherty PF, et al (2024)

Increased Reproductive Output and Telomere Shortening Following Calcium Supplementation in a Wild Songbird.

Ecology and evolution, 14(10):e70483.

Life history theory predicts increased parental investment comes with fitness costs, often expressed as negative effects on survival and future reproduction. To better understand the costs of reproduction and life history trade-offs, we evaluated calcium supplementation at a high-elevation site in Colorado as a novel approach to experimentally alter reproductive investment in nesting female Tachycineta bicolor (tree swallow). Calcium is a nutrient critical to avian reproduction as the intake of natural calcium is essential for egg production, embryo development, and nestling growth. Altering calcium availability exclusively during the breeding season allowed examination of individual biological responses to experimental modification of reproduction, as well as the reproductive costs associated with egg production and laying an entire clutch. As a functional endpoint and proxy for fitness and longevity, telomere length was measured at the beginning and end of each breeding season. Telomeres-protective "caps" at the ends of chromosomes-have been shown to shorten with aging and a variety of stressors, including higher reproductive output. Results demonstrate that tree swallow mothers supplemented with calcium during the breeding season experience higher reproductive output and produce offspring with longer telomeres, which came at the cost of relatively shorter telomeres during the reproductive season. These findings provide additional support for reproductive trade-offs, and also challenge previous calcium supplementation studies that suggest excess calcium reduces the cost of reproduction.

RevDate: 2024-10-28

Savage SA, Bertuch AA, Team Telomere and the Clinical Care Consortium for Telomere‐Associated Ailments (CCCTAA) (2024)

Different phenotypes with different endings-Telomere biology disorders and cancer predisposition with long telomeres.

British journal of haematology [Epub ahead of print].

Rare germline pathogenic variants (GPVs) in genes essential in telomere length maintenance and function have been implicated in two broad classes of human disease. The telomere biology disorders (TBDs) are a spectrum of life-threatening conditions, including bone marrow failure, liver and lung disease, cancer and other complications caused by GPVs in telomere maintenance genes that result in short and/or dysfunctional telomeres and reduced cellular replicative capacity. In contrast, cancer predisposition with long telomeres (CPLT) is a disorder associated with elevated risk of a variety of cancers, primarily melanoma, thyroid cancer, sarcoma, glioma and lymphoproliferative neoplasms caused by GPVs in shelterin complex genes that lead to excessive telomere elongation and increased cellular replicative capacity. While telomeres are at the root of both disorders, the term TBD is used to convey the clinical phenotypes driven by critically short or otherwise dysfunctional telomeres and their biological consequences.

RevDate: 2024-10-27
CmpDate: 2024-10-27

Qi Y, Shan D, Cao Y, et al (2024)

Telomere-to-telomere Genome Assembly of two representative Asian and European pear cultivars.

Scientific data, 11(1):1170.

As the third most important temperate fruit, Pear (Pyrus spp.) exhibits a remarkable genetic diversity and is classified into two mainly categories known as Asian pear and European pear. Although several pear genomes are available, most of the released versions are fragmented and not chromosome-level high-quality. In this study, we report two high-quality genomes for Pyrus bretschneideri Rhed. cv. 'Danshansuli' (DS) and Pyrus communis L. cv. 'Conference' (KFL), which represent the predominant Asian and European cultivars, respectively, with nearly telomere-to-telomere (T2T) gap-free level. The finally assembled genome sizes for DS and KFL were 510.98 Mb and 510.71 Mb, respectively, with Contig N50 of 29.47 Mb and 30.47 Mb, where each chromosome was represented by a single contig. The DS and KFL genomes yielded a total of 46,394 and 44,702 protein-coding genes, respectively. Among these genes, the functional annotation accounted for 96.47% and 96.46% in the DS and KFL genomes. The two novels nearly T2T genomic information offers an invaluable resource for comparative genomics, genetic diversity analysis, molecular breeding strategies, and functional exploration.

RevDate: 2024-10-26

Rattan P, Nguyen K, Penrice DD, et al (2024)

Underrecognized Association of Porto-Sinusoidal Vascular Disorder and Telomere Biology Disorders.

RevDate: 2024-10-26
CmpDate: 2024-10-26

Lee SH, Kim TK, Yoo JH, et al (2024)

Analysis of the Association between Telomere Length and Neurological Disability in Stroke Types.

Medicina (Kaunas, Lithuania), 60(10): pii:medicina60101657.

Background and Objectives: The association between neurological disability, prognosis, and telomere length (TL) in patients with stroke has been investigated in various ways. However, analysis of the type of stroke and ischemic stroke subgroups is limited. In this study, we aimed to determine the association between TL and neurological disability according to stroke type. Materials and Methods: This prospective study included patients with stroke who visited a single-center emergency department (ED) between January 2022 and December 2023. The association between TL and neurological disabilities, using the Modified Rankin Scale (mRS) and National Institutes of Health Stroke Scale (NIHSS), was evaluated according to the patient's stroke type and subgroup of ischemic stroke. Multivariate analysis was performed to determine the association between neurological disabilities in patients with ischemic stroke and the subgroups. Results: A total of 271 patients with stroke were enrolled. The NIHSS score was found to be higher at the time of ED visit (adjusted odds ratio [OR], 5.23; 95% confidence interval [CI], 1.59-17.2, p < 0.01) and 1 day later (adjusted OR, 7.78; 95% CI, 1.97-30.70, p < 0.01) in the ischemic stroke group with a short TL. In the other determined etiology (OD) or undetermined etiology (UD) group, the NIHSS was higher in the short TL group at the ED visit (adjusted OR, 7.89; 95% CI, 1.32-47.25, p = 0.02) and 1 day after (adjusted OR, 7.02; 95% CI, 1.14-43.47, p = 0.04). Conclusions: TL is associated with neurological disability in early ischemic stroke and is prominent in the UD and OD subgroups.

RevDate: 2024-10-26

Zole E, Baumanis E, Freimane L, et al (2024)

Changes in TP53 Gene, Telomere Length, and Mitochondrial DNA in Benign Prostatic Hyperplasia Patients.

Biomedicines, 12(10): pii:biomedicines12102349.

BACKGROUND: Benign prostatic hyperplasia (BPH) is a growing issue due to an ageing population. Our study investigated the possible associations between BPH and ageing hallmarks, including the telomere length (TL) and mitochondrial genome copy number (mtDNA CN), along with genetic variations in the TP53 gene and mtDNA.

METHODS: Prostate tissue samples were obtained from 32 patients with BPH, together with 30 blood samples. As a healthy control group, age-matching blood DNA samples were used. For the comparison of mtDNA sequence data, 50 DNA samples of the general Latvian population were used. The full mtDNA genome was analyzed by using Next-Generation Sequencing (NGS), the TP53 gene by Sanger sequencing, and the mtDNA copy number (mtDNA CN) and telomere length (TL) byqPCR assay.

RESULTS: The results showed that in BPH patients, telomeres in the prostate tissue were significantly longer than in blood cells, while the TL in blood cells of the healthy controls was the shortest. Also, the mtDNA amount in the prostate tissue of BPH patients was significantly greater in comparison with blood cells, and controls had the smallest mtDNA CN. We did not find any mutations in the TP53 gene that could be linked to BPH; however, in mtDNA, we found several unique mutations and heteroplasmic changes, as well as genetic changes that have been previously associated with prostate cancer.

CONCLUSIONS: In conclusion, prolonged telomeres and changes in the mtDNA amount might be involved in the molecular mechanisms of BPH. Some of the heteroplasmic or homoplasmic mtDNA variants might also contribute to the development of BPH. Additional studies are needed to substantiate these findings.

RevDate: 2024-10-26

Villar-Juárez GE, Genis-Mendoza AD, Martínez-López JNI, et al (2024)

Exploring the Relationship between Telomere Length and Cognitive Changes in Post-COVID-19 Subjects.

Biomedicines, 12(10): pii:biomedicines12102296.

BACKGROUND/OBJECTIVES: Emerging evidence suggests that patients suffering from COVID-19 may experience neurocognitive symptoms. Furthermore, other studies indicate a probable association between leukocyte telomere length (LTL) and neurocognitive changes in subjects with post-COVID-19 condition. Our study was designed to determine the correlation between telomere length and cognitive changes in post-COVID-19 subjects.

METHODS: This study included 256 subjects, categorized based on SARS-CoV-2 infection from 2020 to 2023. In addition, subjects with a psychiatric diagnosis were considered. Moreover, the MoCA and MMSE scales were applied. Telomere length was determined using a polymerase chain reaction, and statistical analysis was employed using ANOVA and X[2] tests.

RESULTS: We identified a decrease in LTL in individuals with post-COVID-19 conditions compared to those without SARS-CoV-2 infection (p ≤ 0.05). However, no association was found between LTL and cognitive impairment in the subjects post-COVID-19.

CONCLUSIONS: The findings suggest that LTL is affected by SARS-CoV-2 infection. Nonetheless, this important finding requires further research by monitoring neurological changes in subjects with post-COVID condition.

RevDate: 2024-10-26

Kapetanou M, Athanasopoulou S, Goutas A, et al (2024)

α-Terpineol Induces Shelterin Components TRF1 and TRF2 to Mitigate Senescence and Telomere Integrity Loss via A Telomerase-Independent Pathway.

Antioxidants (Basel, Switzerland), 13(10): pii:antiox13101258.

Cellular senescence is a hallmark of aging characterized by irreversible growth arrest and functional decline. Progressive telomeric DNA shortening in dividing somatic cells, programmed during development, leads to critically short telomeres that trigger replicative senescence and thereby contribute to aging. Therefore, protecting telomeres from DNA damage is essential in order to avoid entry into senescence and organismal aging. In several organisms, including mammals, telomeres are protected by a protein complex named shelterin that prevents DNA damage at the chromosome ends through the specific function of its subunits. Here, we reveal that the nuclear protein levels of shelterin components TRF1 and TRF2 decline in fibroblasts reaching senescence. Notably, we identify α-terpineol as an activator that effectively enhances TRF1 and TRF2 levels in a telomerase-independent manner, counteracting the senescence-associated decline in these crucial proteins. Moreover, α-terpineol ameliorates the cells' response to oxidative DNA damage, particularly at the telomeric regions, thus preserving telomere length and delaying senescence. More importantly, our findings reveal the significance of the PI3K/AKT pathway in the regulation of shelterin components responsible for preserving telomere integrity. In conclusion, this study deepens our understanding of the molecular pathways involved in senescence-associated telomere dysfunction and highlights the potential of shelterin components to serve as targets of therapeutic interventions, aimed at promoting healthy aging and combating age-related diseases.

RevDate: 2024-10-26
CmpDate: 2024-10-26

Han F, Riaz F, Pu J, et al (2024)

Connecting the Dots: Telomere Shortening and Rheumatic Diseases.

Biomolecules, 14(10): pii:biom14101261.

Telomeres, repetitive sequences located at the extremities of chromosomes, play a pivotal role in sustaining chromosomal stability. Telomerase is a complex enzyme that can elongate telomeres by appending telomeric repeats to chromosome ends and acts as a critical factor in telomere dynamics. The gradual shortening of telomeres over time is a hallmark of cellular senescence and cellular death. Notably, telomere shortening appears to result from the complex interplay of two primary mechanisms: telomere shelterin complexes and telomerase activity. The intricate interplay of genetic, environmental, and lifestyle influences can perturb telomere replication, incite oxidative stress damage, and modulate telomerase activity, collectively resulting in shifts in telomere length. This age-related process of telomere shortening plays a considerable role in various chronic inflammatory and oxidative stress conditions, including cancer, cardiovascular disease, and rheumatic disease. Existing evidence has shown that abnormal telomere shortening or telomerase activity abnormalities are present in the pathophysiological processes of most rheumatic diseases, including different disease stages and cell types. The impact of telomere shortening on rheumatic diseases is multifaceted. This review summarizes the current understanding of the link between telomere length and rheumatic diseases in clinical patients and examines probable telomere shortening in peripheral blood mononuclear cells and histiocytes. Therefore, understanding the intricate interaction between telomere shortening and various rheumatic diseases will help in designing personalized treatment and control measures for rheumatic disease.

RevDate: 2024-10-25
CmpDate: 2024-10-25

Hassanpour H, Javdani M, Changaniyan-Khorasgani Z, et al (2024)

Is castration leading to biological aging in dogs? Assessment of lipid peroxidation, inflammation, telomere length, mitochondrial DNA copy number, and expression of telomerase and age-related genes.

BMC veterinary research, 20(1):485.

BACKGROUND: Biological aging is a complex process influenced by various factors, including reproductive status and castration. This study aimed to evaluate the impact of castration on biological aging in dogs.

METHOD: Fifteen male crossbred dogs were randomly divided into a sham-operation control group (n = 5) and a castrated group (n = 10). Blood samples were collected at weeks 0, 4, 8, 12, 16, and 18 post-surgery. Malondialdehyde (MDA as indicator of Lipid peroxidation), C-reactive protein (as an indicator of inflammation), telomere length, mitochondrial DNA (mtDNA) copy number, and the expression of age-related (P16, P21, TBX2) and telomerase-related (TERT) genes were assessed in blood samples.

RESULTS: Plasma MDA levels were higher in the control group at weeks 16 and 18, while CRP levels were higher only at week 18. Telomere length and mtDNA copy number were lower in the control group at week 18. Gene expression analysis showed that P16 was lower in the control group at weeks 8 and 12, P21 and TERT were lower at weeks 16 and 18, and TBX2 was lower at weeks 16 and 18. The TBX2/P16 ratio was lower in the control group at weeks 16 and 18 but higher at week 12, while the TBX2/P21 ratio did not differ between groups.

CONCLUSION: Castration appears to have a protective effect against biological aging in dogs, as evidenced by lower lipid peroxidation, inflammation, and age-related changes in telomere length, mtDNA copy number, and gene expression.

RevDate: 2024-10-24

Domínguez-de-Barros A, Sifaoui I, Dorta-Guerra R, et al (2024)

Telomere- and oxidative stress dynamics in Psittacidae species with different longevity trajectories.

GeroScience [Epub ahead of print].

Telomeres, conserved DNA sequences at chromosome ends, naturally shorten with age, exacerbated by external factors like environmental challenges and reproduction. Birds, particularly psittacine, are gaining prominence as new aging models over the years because of their unique characteristics. This study explores erythrocyte telomere length (TL) and oxidative stress markers in plasma of long- and short-lived captive birds of the order Psittaciformes over four years. Long-lived birds consistently exhibited longer TL than short-lived ones (p = 0.012) but experienced a more pronounced TL shortening rate (p < 0.001) than short-lived ones. Breeding individuals experienced increased TL shortening compared to non-reproductive counterparts in long-lived birds (p = 0.008). Interestingly, long-lived birds showed a higher total antioxidant capacity than short-lived ones (p < 0.001), which was also increased during breeding (p = 0.026). A significant correlation was found between the telomere length shortening rate within the 4 years of study and the accumulated oxidative stress (r = 0.426, p = 0.069) in short-lived birds. These findings shed light on TL and oxidative stress dynamics over time, revealing distinct patterns influenced by life-traits among longevity groups.

RevDate: 2024-10-24
CmpDate: 2024-10-24

Kandemir I, Sahin AY, Oyaci Y, et al (2024)

Effect of obesity and NAFLD on leukocyte telomere length and hTERT gene MNS16A VNTR variant.

Scientific reports, 14(1):25055.

It is known that telomere length (TL) (evaluated with T/S ratio) is shortened in the presence of obesity. In this study, we aimed to investigate how obesity in adolescents and non-alcoholic liver disease (NAFLD) within the obese group affect TL and the clinical significance of the human telomerase reverse transcriptase (hTERT) gene MNS16A VNTR variant in terms of NAFLD. Adolescents with exogenous obesity and healthy controls (aged 10-19 years) who applied to our adolescent outpatient clinic between May-October 2023 were included in this study. We performed upper abdominal ultrasonography to investigate the presence of NAFLD in adolescents with obesity and divided into two groups: those without hepatosteatosis (obese NAFLD (-)) and those with hepatosteatosis (obese NAFLD (+)). We recorded body weight, height, waist circumference, and blood pressure measurements and measured the T/S ratio (telomere sequence copy number/gene single copy number) by the Quantitative Polymerase Chain Reaction method. The groups were compared using frequentist and Bayesian methods. Eighty-three obese adolescents [63 NAFLD(+) 20 NAFLD(-)] and 69 lean controls were included in the study. Pairwise comparisons revealed that T/S ratio was significantly lower in the obese NAFLD (-) group than the obese NAFLD (+) and the control group (p = 0.025, p = 0.007, respectively). T/S ratio was lower in the LL allele group than in the other alleles (p = 0.022) and slightly higher in the obese group with metabolic syndrome compared to the obese group without metabolic syndrome (p = 0.072). hTERT-MNS16A-VNTR gene variant LL allele had a negative correlation with T/S ratio among the obese adolescent group. Patients with LL alleles had higher ALT, GGT, HOMA-IR, and ALT/AST. Diastolic blood pressure had a significant correlation with the T/S ratio. The T/S ratio was shorter in the obese adolescent group compared to healthy ones but was higher in the NAFLD (+) obese compared to the NAFLD (-) obese. ALT level and ALT/AST ratio were higher, T/S ratio was lower in the hTERT MNS16A VNTR variant LL allele group among obese adolescents. In addition, there was a significant correlation between the T/S ratio and diastolic blood pressure in obese adolescents.

RevDate: 2024-10-23

Gao Q, Yu J, Liu Y, et al (2024)

Elevated 1-Hour Post Load Glucose as a Predictor for Telomere Attrition: a study based on a Chinese Community population.

The Journal of clinical endocrinology and metabolism pii:7831863 [Epub ahead of print].

CONTEXT: 1-hour post-load glucose (1h-PG) detects dysglycemia-related disorders more effectively than traditional glycemic parameters. Hyperglycemia accelerates aging, whether 1h-PG outperforms in predicting aging remains unclear.

OBJECTIVE: To Compare the effectiveness of 1h-PG with other glycemic parameters in identifying and predicting telomere attrition.

METHODS: We conducted a cross-sectional and longitudinal study based on a Chinese community cohort. Multivariate linear regression and logistic regression were used to analyze the associations between glycemic parameters and telomere length. The area under the receiver operating characteristic (AUROC) curve were used to compare the differentiating and predictive ability. Populations were regrouped by glucose tolerance status and 1h-PG to compare telomere length. Analyses were separately conducted in non-diabetic and diabetic populations.

RESULTS: The cross-sectional study included 715 participants. Only 1h-PG was significantly negatively associated with RTL in both non-diabetic (β = -0.106, 95%CI -0.068 to -0.007, P = 0.017) (odds ratio [OR] = 1.151, 95% CI 1.069 to 1.239, P = 0.005) and diabetic (β = -0.222, 95%CI -0.032 to -0.007, P = 0.002) (OR = 1.144, 95% CI 1.041 to 1.258, P = 0.035) populations. The longitudinal study recruited 437 populations and 112 remained in 7-years follow-up. 1h-PG was associated with telomere shortening in the non-diabetic group (β = -0.314, 95%CI -0.276 to -0.032, P = 0.016) (OR = 2.659, 95% CI 1.158 to 6.274, P = 0.021). AUROC analysis showed that 1h-PG outperformed other glycemic parameters in identifying and predicting telomere attrition. Reclassification revealed that normal glucose tolerance and prediabetic individuals with elevated 1h-PG had telomere lengths comparable to prediabetic and diabetic populations, respectively.

CONCLUSIONS: 1h-PG outperforms other glycemic parameters in predicting telomere attrition and can be a valuable marker for early aging detection.

RevDate: 2024-10-23

Coulter T, Hill C, AJ McKnight (2024)

Insights into the length and breadth of methodologies harnessed to study human telomeres.

Biomarker research, 12(1):127.

Telomeres are protective structures at the end of eukaryotic chromosomes that are strongly implicated in ageing and ill health. They attrition upon every cellular reproductive cycle. Evidence suggests that short telomeres trigger DNA damage responses that lead to cellular senescence. Accurate methods for measuring telomeres are required to fully investigate the roles that shortening telomeres play in the biology of disease and human ageing. The last two decades have brought forth several techniques that are used for measuring telomeres. This editorial highlights strengths and limitations of traditional and emerging techniques, guiding researchers to choose the most appropriate methodology for their research needs. These methods include Quantitative Polymerase Chain Reaction (qPCR), Omega qPCR (Ω-qPCR), Terminal Restriction Fragment analysis (TRF), Single Telomere Absolute-length Rapid (STAR) assays, Single TElomere Length Analysis (STELA), TElomere Shortest Length Assays (TESLA), Telomere Combing Assays (TCA), and Long-Read Telomere Sequencing. Challenges include replicating telomere measurement within and across cohorts, measuring the length of telomeres on individual chromosomes, and standardised reporting for publications. Areas of current and future focus have been highlighted, with recent methodical advancements, such as long-read sequencing, providing significant scope to study telomeres at an individual chromosome level.

RevDate: 2024-10-22

Tyer C (2024)

High-resolution measurement of individual telomere lengths with Telo-seq.

Nature reviews. Cancer [Epub ahead of print].

RevDate: 2024-10-22

Anonymous (2024)

Erratum: Targeting Telomere Dynamics as an Effective Approach for the Development of Cancer Therapeutics [Corrigendum].

International journal of nanomedicine, 19:10367-10368 pii:500182.

[This corrects the article DOI: 10.2147/IJN.S448556.].

RevDate: 2024-10-21
CmpDate: 2024-10-21

Dai H, Z Chen (2024)

Association between dietary vitamin K and telomere length: Based on NHANES 2001 to 2002.

Medicine, 103(42):e40157.

As an anti-inflammatory and antioxidant, vitamin K has the potential to reduce telomere attrition. However, the correlation between dietary vitamin K and telomere length (TL) has not been reported. We aimed to investigate the association between these 2 variables. This study included 3754 participants from the National Health and Nutrition Examination Survey 2001-2002 database. We used multivariate linear regression and restricted cubic splines to assess the relationship between dietary vitamin K intake and TL. Subgroup analyses and interaction tests were utilized to examine the stability of the results. After adjusting for all variables, each unit increase in daily dietary intake of vitamin K lengthened telomeres by 0.22 base pairs (β = 0.22, 95% CI: 0.09-0.36, P = .001). Individuals with the highest dietary vitamin K intake had significantly longer TL (β = 80.27, 95% CI: 20.83-139.71, P = .008). Subgroup analyses suggested that this association persisted in populations stratified by gender, age, diabetes, cardiovascular disease (CVD), body mass index and total energy intake (P for interaction > .05). A linear relationship between dietary vitamin K intake and TL was observed in restricted cubic splines (P for nonlinear = .554). In conclusion, our findings suggest that dietary vitamin K intake is positively associated with TL, providing recent evidence to guide the management of healthy diets.

RevDate: 2024-10-21

Ding X, Zhang Y, S You (2024)

A novel prognostic model based on telomere-related lncRNAs in gastric cancer.

Translational cancer research, 13(9):4608-4624.

BACKGROUND: Telomeres are specialized structures at the ends of chromosomes that are important for their protection. Over time, long non-coding RNAs (lncRNAs) have gradually come into the spotlight as essential biomarkers of proliferation, migration, and invasion of human malignant tumors. Nevertheless, the impact of telomere-related lncRNAs (TRLs) in gastric cancer is currently unknown. In the present study, we screen the TRLs and identify a prognostic TRLs signature in gastric cancer.

METHODS: First, telomere-related genes (TRGs) were retrieved from the website, and RNA sequencing (RNA-seq) data and clinical data of stomach adenocarcinoma (STAD) patients were gathered from The Cancer Genome Atlas (TCGA) database. Gastric cancer patients' lncRNAs and overall survival (OS) were found to be related using univariate Cox regression analysis. Next, least absolute shrinkage and selection operator (LASSO) regression analysis and multifactorial Cox regression analysis were used to further screen telomere-related differentially expressed lncRNAs (TRDELs), and finally six lncRNAs were obtained, including LINC01537, CFAP61-AS1, DIRC1, RABGAP1L-IT1, DBH-AS1, and REPIN1-AS1. According to these six TRDELs, a prognostic model for gastric cancer was constructed. The samples were divided into the training group and the testing group at random, and the reliability of prognostic model was validated in both groups and overall samples. In addition, we performed Kaplan-Meier (K-M) survival curve analysis, independent prognostic analysis, and functional enrichment analysis to validate the predictive value and independence of the model, as well as immune cell correlation analysis, clustering analysis, and principal component analysis (PCA) to further explore the relationship between this model and the tumor cells. Finally, we performed the drug sensitivity analysis to identify a few small molecules that may have a therapeutic effect on gastric cancer.

RESULTS: Finally, we constructed a prognostic model for gastric cancer consisting of six TRDELs. According to the K-M curve, the prognosis of the low-risk group was noticeably superior than that of the high-risk group. Multivariate Cox regression analysis suggested that risk score was an independent prognostic element. Receiver operating characteristic (ROC) curves, nomogram, and calibration curve indicated that the prognostic model had good predictive ability. Functional enrichment analysis demonstrated major pathways with high- and low-risk groups. Next, both tumor microenvironment (TME) and immune correlation analysis showed discrepancy in the high- and low-risk groups. Through drug sensitivity analysis, we screened four small molecules that might be beneficial for gastric cancer treatment.

CONCLUSIONS: A prognostic model consisting of these six TRDELs was capable to predict the prognosis of gastric cancer patients.

RevDate: 2024-10-21

Lin H, W Yin (2024)

Telomere-related prognostic signature for survival assessments in lung adenocarcinoma.

Translational cancer research, 13(9):4520-4533.

BACKGROUND: Telomere-related genes (TRGs) are important in many different types of cancers. However, there is a lack of research on the relationship between their expression and prognosis in lung adenocarcinoma (LUAD) patients. This study is to investigate the prognostic value of TRGs in LUAD and to develop a TRG signature that can predict patient survival.

METHODS: A total of 2,086 TRGs were obtained from a database of genes involved in telomere maintenance (TelNet), while the clinical information and tumor RNA expression profiles of 513 LUAD patients were acquired from The Cancer Genome Atlas (TCGA) database. Statistical methodologies, such as least absolute shrinkage and selection operator (LASSO)-Cox, were employed to construct a prognostic model with predictive capabilities.

RESULTS: We analyzed 1,339 telomere-associated differentially expressed genes and identified a ten-gene predictive signature for LUAD. This signature exhibited effective prognostic classification capabilities across multiple datasets, including GSE3141 (58 samples), GSE8894 (63 samples), GSE50081 (127 samples), and GSE72094 (398 samples). Furthermore, we screened tumor-sensitive drugs targeting this signature. High telomere levels were associated with reduced survival in lung cancer patients who underwent surgery. Compared to the traditional TNM (tumor node metastasis classification) grading method, our telomere-associated gene panel demonstrated superior prediction accuracy. Notably, patients in the high-risk group, defined by the telomere-associated signature, exhibited improved responses to immunotherapy, suggesting potential benefits for this subgroup of patients.

CONCLUSIONS: This study presents a comprehensive molecular signature comprising TRGs, which holds potential for functional and therapeutic investigations. Additionally, it serves as an integrated tool to identify crucial molecules for immunotherapy in lung cancer.

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In the early 1990's, Robert Robbins was a faculty member at Johns Hopkins, where he directed the informatics core of GDB — the human gene-mapping database of the international human genome project. To share papers with colleagues around the world, he set up a small paper-sharing section on his personal web page. This small project evolved into The Electronic Scholarly Publishing Project.

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Although multicellular eukaryotes (MCEs) are the most visible component of the biosphere, they represent a highly derived and constrained evolutionary subset of the biosphere, unrepresentative of the vast, mostly unseen, microbial world of prokaryotic life that comprises at least half of the planet's biomass and most of its genetic diversity. The existence of telomeres is one component of the specialized biology of eukaryotes. R. Robbins

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