Telomere Length Research Articles

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

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

Telomere length as a biomarker for cerebrovascular diseases: current evidence

Telomere length as a biomarker for cerebrovascular diseases: current evidence

Abstract 4131618: Association between Clinical Characteristics and Telomere Length - Factor Analysis of Mixed Data (FAMD)-based Cluster Analysis

Introduction: Telomere length is a marker of cellular aging and is correlated with various cardiovascular risk factors. Aim: To assess the association between clinical characteristics of patients and telomere length in an unselected cohort of patients under the care of primary care physicians. Methods: The LIPIDOGEN study was carried out in the primary care 2015. Patients recruited to LIPIDOGEN cohort (n=1788) were a random subset of patients of LIPIDOGRAM 2015 (n=13,724) study. Patients for LIPIDOGRAM2015/LIPIDOGEN study were recruited in all 16 administrative regions in Poland. Each patient was asked to fill the questionnaire on risk factors, chronic, treatment and lifestyle and also had saliva secured for DNA analyses. Factor Analysis for Mixed Data (FAMD) based cluster analysis was utilized to discern groups of patients with similar clinical profiles and correlate them with relative telomere length (rTL). RTL was measured using quantitative polymerase chain reaction. Results: DNA quality was sufficient for further analyses in 1606 patients. After outlier exclusion, 1,342 patients (59.3% female, mean age 50.2 years) were analyzed. FAMD revealed two distinct clinical characteristic patterns, explaining 41.6% of the total variance in the clinical variables. The first pattern, correlated with male gender and a higher prevalence of MetS, hypertension, diabetes, obesity, greater waist circumference, elevated non-HDL-C and remnant-C levels, was linked to shorter rTL (r = -0.13, p < 0.001). The second pattern, characterized mainly by lipid parameters, showed no significant association with comorbidities or rTL (r = -0.04, p = 0.14). Conclusions: Pattern of clinical characteristics marked by classical cardiovascular risk factors, is inversely related to telomere length, underlining the potential role of metabolic disturbances in cellular aging. The second lipid-centric pattern without significant comorbidities was not associated with telomere length.

Abstract 4145812: Cardiovascular MRI-Derived Cardiac Age Acceleration is Associated with Shortened Leukocyte Telomere Length But Not Clonal Hematopoiesis of Indeterminate Potential

Introduction: Cardiac structure and function typically decline with age. Abnormal acceleration of this decline, known as cardiac age acceleration, can be estimated from MRI using deep learning. Both general and cardiac-specific mechanisms may contribute to cardiac aging. Longer telomere length in circulating leukocytes, which indicates greater cellular capacity for replication, has been associated with a lower risk of heart failure and more favorable cardiac structure and function Recent data have also suggested that longer telomeres contribute to risk of clonal hematopoiesis of indeterminate potential (CHIP), which has been linked to increased risk of atherosclerosis, heart failure and arrhythmia. Here we studied whether telomere length or CHIP status are associated with deep learning derived cardiac age acceleration. Methods: We developed a deep learning model to estimate cardiac age acceleration in 70,805 UK Biobank participants from the cardiovascular MRI (four-chamber long axis view). Of these, we identified leukocyte telomere length (LTL) in 61,554 and were able to evaluate CHIP in 61,636. In an additional 372,465 participants unrelated to those with imaging, a genome-wide association study (GWAS) was conducted for LTL, and a GWAS of cardiac age acceleration was conducted in those with imaging; using these, a two-sample Mendelian randomization (MR) was performed to identify putatively causal relationships. Results: In the 61,636 participants with both CHIP and cardiac age acceleration measurements, CHIP was not associated with cardiac age acceleration regardless of driver gene (p=0.79). In contrast, cardiac age acceleration was associated with a shorter LTL (Beta=-0.025 SD, p=5.4E-10). Shorter LTL was causally associated with cardiac age acceleration (Beta=-0.10, p=0.047). Conclusions: These data suggest that general aging mechanisms conferred by shortening telomeres may contribute to the age-associated structural and functional decline of the heart as observed with MRI. In comparison, the relationship between CHIP and cardiovascular risk may not manifest in ways that cause apparent cardiac age acceleration.

Abstract 4139176: SUMOylation of TP53INP1 Is Involved in miR-30a-5p-Regulated Heart Senescence

Introduction: During natural aging, physiological remodeling of the heart is a critical for the cardiovascular disease and heart failure. miR-30a-5p is related to kidney injury, cancer, and autoimmune diseases. However, whether miR-30a-5p has an effect in cardiac aging has yet to be explored. Hypothesis: This study aimed to characterize the role and mechanism of action of miR-30a-5p in cardiac senescence. Methods: We established miR-30a-5p knockout/overexpressing mouse model. Natural heart aging (18-months-old) and D-galactose-induced aging mouse model were established. The mechanism was explored in D-galactose- or 10-days-cultured cardiomyocytes. Results: miR-30a-5p was downregulated in aged mouse hearts and neonatal rat cardiomyocytes (NRCMs). In vivo, using a combination of echocardiography and different molecular biological approaches, we investigated the role of miR-30a-5p knockout or overexpressed mice on natural- or D-galactose-induced heart aging. In vitro, using RNA-sequence and a series of molecular biology, the mechanism of miR-30a-5p-regulated cardiac senescence was explored in cardiomyocytes. miR-30a-5p knockout mice showed aggravated natural- or D-galactose-induced heart aging compared to wild-type littermate mice, with significantly decreased heart function, increased number of γH2AX-positive cells, reduced telomere length, and upregulated p21 and p53 expression. Cardiac-specific knockdown of miR-30a-5p using adeno-associated virus 9 in D-galactose-induced senescent wild-type mice showed effects similar to those observed in knockout mice. Notably, overexpression of miR-30a-5p in wild-type murine hearts alleviated D-galactose-induced heart senescence by improving heart function, increasing telomere length, decreasing the number of γH2AX-positive cells, and downregulating p53 and p21 expression. This was confirmed in D-galactose-treated or naturally aged NRCMs. Mechanistically, TP53INP1 was identified as a target of miR-30a-5p by mediating the SUMOylation of TP53INP1 and its translocation from the cytoplasm to the nucleus to interact with p53. Further evidence demonstrated that cardiac-specific TP53INP1 deficiency ameliorates miR-30a-5p knockout-aggravated cardiac dysfunction and heart senescence. Conclusions: This study identified miR-30a-5p as a crucial modulator of heart senescence and revealed that the miR-30a-5p–TP53INP1–p53 axis is essential for heart and cardiomyocyte aging.

Abstract 4139115: Genomic, Phenomic, and Geographic Relationships with Leukocyte Telomere Length in the U.S. Yields New Insights for Neoplasms and Cardiometabolic Disease

Background: Leukocyte telomere length (LTL) is an age-related marker strongly associated with neoplasms and cardiometabolic disease. LTL is also intimately linked with clonal hematopoiesis of indeterminate potential (CHIP), a recently described risk factor for cardiovascular disease (CVD). However, population-scale investigations of LTL in diverse backgrounds are limited, and geolocational variance has not been studied. Method: LTL and CHIP were derived using blood-derived whole genome sequencing data from 244,819 diverse U.S. residents in the NIH All of Us Research Program (AoU). We performed association analyses of LTL with CHIP and other available health-related traits, Phecode, as well as geolocation data by ZIP code. Genome-wide association study (GWAS) of LTL in AoU and meta-analysis with UK Biobank were performed. All association tests were adjusted for age, sex, sequencing site, and the first 10 genetic principal components with multiple test corrections. Mediation analysis was adjusted for additional risk factors for CVD. Result: Among 244,819 AoU participants, 146,717 (59.9%) were female with mean (standard deviation) age 51.8 (±16) years. Estimated LTL correlated strongly with age, sex, and genetic ancestry in AoU. Socioeconomic status, lifestyle variables, anthropometry, blood biomarkers (e.g., lipids and glucose), and vital signs were associated with LTL in AoU. Phecode analysis showed LTL is associated with neoplasms and age-related conditions, including CVDs. LTL mediated some of the observed increased coronary artery disease risk among individuals with hematologic malignancies ( P < 2 × 10 -16 ). Significantly longer LTL clustered in the West Coast and Central Midwest ( P = 0.001 and 0.033, respectively), while significantly shorter LTL clustered in the Southeast ( P = 0.001) (Figure). GWAS meta-analyses identified 197 loci, of which 36 (18%) were novel, including ancestry-specific loci. Rare variant aggregation test found 9 novel associated genes. Conclusions: LTL is a marker of biological age that is associated and interacts with neoplasms, CVDs, and its various risk factors, with notable geographic variability within the U.S. Germline genetic analyses of LTL yield new insights into drivers of LTL.

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

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

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

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

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

ABSTRACT 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.

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

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.

SUMOylation of TP53INP1 is involved in miR-30a-5p-regulated heart senescence.

Heart senescence is critical for cardiac function. This study aimed to characterize the role and mechanism of action of miR-30a-5p in cardiac senescence. miR-30a-5p was downregulated in aged mouse hearts and neonatal rat cardiomyocytes (NRCMs). In vivo, using a combination of echocardiography and different molecular biological approaches, we investigated the role of miR-30a-5p knockout or overexpression in natural- or D-galactose-induced heart aging in mice. In vitro, using RNA sequencing and a series of molecular biology methods, the mechanism by which miR-30a-5p regulates cardiac senescence was explored in cardiomyocytes. miR-30a-5p knockout mice showed aggravated natural- or D-galactose-induced heart aging compared to wild-type littermate mice, with significantly decreased heart function, an increased number of γH2AX-positive cells, reduced telomere length, and upregulated p21 and p53 expression. Cardiac-specific knockdown of miR-30a-5p using adeno-associated virus 9 in D-galactose-induced senescent wild-type mice resulted in effects similar to those observed in knockout mice. Notably, the overexpression of miR-30a-5p in wild-type murine hearts alleviated D-galactose-induced heart senescence by improving heart function, increasing telomere length, decreasing the number of γH2AX-positive cells, and downregulating p53 and p21 expression. This was confirmed in D-galactose-treated or naturally aged NRCMs. Mechanistically, TP53INP1 was identified as a target of miR-30a-5p by mediating the SUMOylation of TP53INP1 and its translocation from the cytoplasm to the nucleus to interact with p53. Furthermore, this study demonstrated that cardiac-specific TP53INP1 deficiency ameliorates miR-30a-5p knockout-aggravated cardiac dysfunction and heart senescence. This study identified miR-30a-5p as a crucial modulator of heart senescence and revealed that the miR-30a-5p-TP53INP1-p53 axis is essential for heart and cardiomyocyte aging.

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

ABSTRACT 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.

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

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.

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

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. 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. 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.

Antisenescence Expansion of Mesenchymal Stem Cells Using Piezoelectric β-Poly(vinylidene fluoride) Film-Based Culture.

Regenerative therapies based on mesenchymal stem cells (MSCs) show promise in treating a wide range of disorders. However, the replicative senescence of MSCs during in vitro expansion poses a challenge to obtaining a substantial quantity of high-quality MSCs. In this investigation, a piezoelectric β-poly(vinylidene fluoride) film-based culture plate (β-CP) was developed with an antisenescence effect on cultured human umbilical cord-derived MSCs. Compared to traditional tissue culture plates (TCPs) and α-poly(vinylidene fluoride) film-based culture plates, the senescence markers of p21, p53, interleukin-6 and insulin-like growth factor-binding protein-7, stemness markers of OCT4 and NANOG, and telomere length of MSCs cultured on β-CPs were significantly improved. Additionally, MSCs at passage 18 cultured on β-CPs showed significantly better multipotency and pro-angiogenic capacities in vitro, and higher wound healing abilities in a mouse model. Mechanistically, β-CPs rejuvenated senescent MSCs by improving mitochondrial functions and mitigating oxidative and glycoxidative stresses. Overall, this study presents β-CPs as a promising approach for efficient and straightforward antisenescence expansion of MSCs while preserving their stemness, thereby holding great potential for large-scale production of MSCs for clinical application in cell therapies.

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

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. 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. 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. 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. 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.

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

BackgroundTelomere 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.MethodsUsing 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.ResultsThe 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 (\U0001d6fd = -0.024; 95%CI: -0.050 to 0.001; P = 0.058), the Non-Hispanic White (\U0001d6fd = -0.022; 95%CI: -0.045 to 0.002; P = 0.066), and other race (\U0001d6fd = -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).ConclusionsThis 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.

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

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.

TGF-β superfamily-induced transcriptional activation pathways establish the RAD52-dependent ALT machinery during malignant transformation of MPNSTs

To study telomere maintenance mechanism (TMM) activation during malignant transformation, we compared neurofibroma (NF) and malignant peripheral nerve sheath tumor (MPNST) in the same patient with type-1 neurofibromatosis (NF1), a total of 20 NF-MPNST pairs in 20 NF1 patients. These comparisons minimized genetic bias and contrasted only changes associated with malignant transformation, while subtracting changes that developed upon the transformation of normal cells to the benign tumor. TGF-β superfamily genes were found to activate the PAX and SOX transcription factors, leading to TMM activation. BMPER activates PAX6 through BMP2 and PAX7 through BMP4; BMP15 activates SOX14; and INHBC activates PAX9 and SOX14. The activated PAX and SOX genes sequentially establish the core architecture of the RAD52-dependent alternative lengthening of telomeres (ALT). Specifically, PAX7 activates the recombinase (RAD52) and a negative regulator (SLX4IP). PAX6 and SOX14 activate positive regulators (BLM and BRCA2, respectively). PAX9 and SOX14 activate RAD9B and FEN1, which are responsible for the stability of homologous recombination intermediates and increase, together with RAD52, the telomere length. Telomere elongation achieved by the activation of PAX7 and PAX9 is associated with a poor prognosis. We demonstrated that TGF-β superfamily-induced transcriptional activation pathways activated the RAD52-dependent ALT during malignant transformation of MPNSTs.

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

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.