Low-molecular-weight fucoidan increases telomere length and immunostimulatory effects on NK-92 cells following inhaled anesthetic injury.

Inhaled anesthetics, such as isoflurane, may cause side effects, including short-term immunosuppression and DNA damage. In contrast, low molecular weight fucoidan (LMF), derived from brown seaweed, exhibits promising immunomodulatory effects. In this study, we determined the effect of isoflurane on telomeres and examined the potential of LMF to ameliorate the harmful effects of isoflurane. Male Lewis rats, the mouse lymphoma cell line YAC-1, and the human nature killer cell line NK-92 MI were exposed to isoflurane. The relative telomere length (T/S) ratio and mRNA expression were determined by quantitative PCR. The viability assay was used to assess cell viability. In vivo, 2% isoflurane exposure, which is a clinically relevant concentration, reduced telomere length, and correlated with exposure frequency and duration. Isoflurane concentrations above 2% shortened YAC-1 telomeres, with minimal impact on cell viability. LMF pre-treatment enhanced NK-92 MI cell survival resulting from isoflurane exposure and exerted superior telomere protection compared with LMF post-treatment. Furthermore, adding LMF during isoflurane exposure resulted in a significant increase in IFN-γ, TNF-α, and IL-10 mRNA compared with the untreated group. LMF protected against isoflurane-induced telomere shortening, enhanced NK cell viability, and modulated cytokine expression, thus mitigating postoperative immune suppression and risk of tumor metastasis.

Leukocyte telomere length as a compensatory mechanism in vitamin D metabolism.

Vitamin D deficiency is common among postmenopausal women. Telomere length can be a potential protective mechanism for age-related diseases. The objective of our study is to examine the association of vitamin D supplementation on leukocyte telomere length (LTL) in healthy postmenopausal women with vitamin D deficiency. The study was designed as a placebo-controlled study to investigate the short-term effects of vitamin D supplementation and seasonal changes on vitamin D related parameters, including 25(OH)D, 1,25(OH)2D parathormone (PTH), Vitamin D binding protein (VDBP), vitamin D receptor (VDR), and telomere length in a cohort of postmenopausal women (n = 102). The group was divided as supplementation (n = 52) and placebo groups (n = 50). All parameters were measured before and after treatment. Serum VDBP levels were measured by ELISA method and VDR, GC (VDBP) gene expressions and relative telomere lengths were measured in peripheral blood mononuclear cells (PBMC) using a quantitative real-time PCR method. The results demonstrate that baseline levels were similar between the groups. After vitamin D supplementation 25(OH)D, 1,25(OH)2D, PTH and VDBP levels were changed significantly compared to the placebo group. At the end of the study period, LTL levels were significantly increased in both groups and this change was more prominent in placebo group. The change in GC expression was significant between treatment and placebo groups but VDR expression remained unchanged. Even though the study was designed to solely assess the effects of vitamin D supplementation, LTL was significantly increased in the whole study group in summer months suggesting that LTL levels are affected by sun exposure and seasonal changes rather than supplementation. The study displayed the short-term effect of Vitamin D supplementation on vitamin D, PTH levels, LTL and vitamin D associated gene expressions. The relation between Vitamin D and LTL is not linear and could be confounded by several factors such as the population differences, regional and seasonal changes in sun exposure.

Dietary Exposure to Polychlorinated Biphenyls and Dioxins and Its Relationship to Telomere Length in Subjects Older Than 55 Years from the SUN Project.

Exposure to persistent organic pollutants (POPs) may influence telomere length (TL), which is considered as a marker of biological age associated with the risk of chronic disease. We hypothesized that dietary exposure to polychlorinated biphenyls (PCBs) and dioxins could affect TL. Our aim was to evaluate the association of dietary exposure to PCBs and dioxins with TL. In this cross-sectional study of 886 subjects older than 55 y (mean age: 67.7; standard deviation (SD): 6.1; 27% women) from the "Seguimiento Universidad de Navarra" (SUN) project. TL was determined by real-time quantitative polymerase chain reaction and dietary PCBs and dioxins exposure was collected using a validated 136-item Food Frequency Questionnaire. Multivariable linear regression models were used to control for potential confounding factors. Shorter TL was associated with dietary total PCBs (SD of T/S ratio/(ng/day) = -0.30 × 10-7; 95% CI, -0.55 × 10-7 to -0.06 × 10-7), dioxin-like PCBs (DL-PCBs) (SD of T/S ratio/(pg WHO TEQ (Toxic Equivalents)/day) = -6.17 × 10-7; 95% CI, -11.30 × 10-7 to -1.03 × 10-7), and total TEQ exposure (SD of T/S ratio/(pg WHO TEQ/day) = -5.02 × 10-7; 95% CI, -9.44 × 10-7 to -0.61 × 10-7), but not with dioxins (SD of T/S ratio/(pg WHO TEQ/day) = -13.90 × 10-7; 95% CI, -37.70 × 10-7 to 9.79 × 10-7). In this sample of middle-aged and older Spanish adults, dietary exposure to total PCBs and DL-PCBs alone and together with dioxins was associated with shorter TL. Further longitudinal studies, preferably with POPs measured in biological samples, are needed to confirm this finding.

Novel anti-aging herbal formulation Jing Si displays pleiotropic effects against aging associated disorders.

Common characteristics of aging include reduced somatic stem cell number, susceptibility to cardiac injuries, metabolic imbalances and increased risk for oncogenesis. In this study, Pleiotropic anti-aging effects of a decoction Jing Si herbal drink (JS) containing eight Traditional Chinese Medicine based herbs, with known effects against aging related disorders was evaluated. Adipose derived mesenchymal stem cells (ADMSCs) from 16 week old adult and 24 month old aging WKY rats were evaluated for the age-related changes in stem cell homeostasis. Effects of JS on self-renewal, klotho and Telomerase Reverse Transcriptase expression DNA damage response were determined by immunofluorescence staining. The effects were confirmed in senescence induced human ADMSCs and in addition, the potential of JS to maintain telomere length was evaluated by qPCR analysis in ADMSCs challenged for long term with doxorubicin. Further, the effects of JS on doxorubicin-induced hypertrophic effect and DNA damage in H9c2 cardiac cells; MPP+-induced damages in SH-SY5Y neuron cells were investigated. In addition, effects of JS in maintaining metabolic regulation, in terms of blood glucose regulation in type-II diabetes mice model, and their potential to suppress malignancy in different cancer cells were ascertained. The results show that JS maintains stem cell homeostasis and provides cytoprotection. In addition JS regulates blood glucose metabolism, enhances autophagic clearances in neurons and suppresses cancer growth and migration. The results show that JS acts on multiple targets and provides a cumulative protective effect against various age-associated disorders and therefore it is a candidate pleiotropic agent for healthy aging.

Neuroblastoma-Telomere maintenance, deregulated signaling transduction and beyond.

The childhood malignancy neuroblastoma belongs to the group of embryonal tumors and originates from progenitor cells of the sympathoadrenal lineage. Treatment options for children with high-risk and relapsed disease are still very limited. In recent years, an ever-growing molecular diversity was identified using (epi)-genetic profiling of neuroblastoma tumors, indicating that molecularly targeted therapies could be a promising therapeutic option. In this review article, we summarize the various molecular subtypes and genetic events associated with neuroblastoma and describe recent advances in targeted therapies. We lay a strong emphasis on the importance of telomere maintenance mechanisms for understanding tumor progression and risk classification of neuroblastoma.

Licochalcone A activation of glycolysis pathway has an anti-aging effect on human adipose stem cells.

Licochalcone A (LA) is a chalcone flavonoid of Glycyrrhiza inflata, which has anti-cancer, antioxidant, anti-inflammatory, and neuroprotective effects. However, no anti-aging benefits of LA have been demonstrated in vitro or in vivo. In this study, we explored whether LA has an anti-aging effect in adipose-derived stem cells (ADSCs). We performed ß-galactosidase staining and measured reactive oxygen species, relative telomere lengths, and P16ink4a mRNA expression. Osteogenesis was assessed by Alizarin Red staining and adipogenesis by was assessed Oil Red O staining. Protein levels of related markers runt-related transcription factor 2 and lipoprotein lipase were also examined. RNA sequencing and measurement of glycolysis activities showed that LA significantly activated glycolysis in ADSCs. Together, our data strongly suggest that the LA have an anti-aging effect through activate the glycolysis pathway.

TA-65 does not increase telomere length during post-natal development in house sparrow chicks (Passer domesticus).

Telomeres, protective caps at the end of chromosomes, are often positively related to lifespan and are thought to be an important mechanism of organismal aging. To better understand the casual relationships between telomere length and longevity, it is essential to be able to experimentally manipulate telomere dynamics (length and loss rate). Previous studies suggest that exposure to TA-65, an extract from the Chinese root Astragalus membranaceus, activates telomerase, lengthens telomeres, increases the growth of keratin-based structures, and boosts the immune system in adults. However, telomere loss is expected to be greatest during early life but whether TA-65 has similar effects during this life stage is currently unknown. Here, we experimentally exposed free-living house sparrow (Passer domesticus) chicks to TA-65 during post-natal development and examined the effects on telomere length and loss, growth of keratin-based structures, and a measure of cellular immunity. Contrary to expectation, the growth of keratin-based structures was reduced in TA-65 chicks and in the second year of the study, chicks exposed to TA-65 experienced more telomere loss than controls. Thus, the effects of TA-65 on telomeres and keratin-based structures differ across life stages and future research will be necessary to determine the mechanisms underlying these age-specific effects.

Telomere length and outcome of treatment for pulmonary tuberculosis in a gold mining community.

Telomere length (TL) is a marker of ageing and mitochondrial DNA (mtDNA) is an early marker of inflammation caused by oxidative stress. We determined TL and mtDNA content among active pulmonary tuberculosis (PTB) patients to assess if these cellular biomarkers differed between artisanal miners and non-miners, and to assess if they were predictive of treatment outcome. We conducted a prospective cohort study from August 2018 to May 2019 involving newly diagnosed PTB patients at three outpatient TB clinics in a rural Democratic Republic of Congo. We measured relative TL and mtDNA content in peripheral blood leukocytes (at inclusion) via qPCR and assessed their association with PTB treatment outcome. We included 129 patients (85 miners and 44 non-miners) with PTB (median age 40 years; range 5-71 years, 22% HIV-coinfected). For each increase in year and HIV-coinfection, TL shortened by - 0.85% (- 0.19 to - 0.52) (p ≤ 0.0001) and - 14% (- 28.22 to - 1.79) (p = 0.02) respectively. Independent of these covariates, patients with longer TL were more likely to have successful TB treatment [adjusted hazard ratio; 95% CI 1.27 for a doubling of leucocyte telomere length at baseline; 1.05-1.44] than patients with a shorter TL. Blood mtDNA content was not predictive for PTB outcome. For a given chronological age, PTB patients with longer telomeres at time of diagnosis were more likely to have successful PTB treatment outcome.

Association between nutrient intake and telomere length in Japanese female university students.

OBJECTIVE: Telomere length can be a biomarker of cumulative oxidative stress and inflammation indicating biological aging. Previous studies examined association of nutrient intake with telomere length targeting middle-aged and elderly individuals. This study examined whether dietary macro- and micronutrient intake was associated with telomere length in young females. METHODS: Seventy-four Japanese young females (median (interquartile range) age was 19 (19 - 20) years) participated. We estimated their intake of nutrients (energy, protein, fat, carbohydrate, essential elements, vitamins, fatty acids, and dietary fibre) using a semi-quantitative food frequency questionnaire and measured telomere length (T/S ratio, the ratio of telomere repeat copy number (T) to single-copy gene number (S)) of DNA extracted from blood by qPCR. The association between telomere length and tertiles of nutrient intake were analysed. RESULTS: The median (interquartile range) of telomere length was 0.70 (0.52 - 0.98). Vitamin A intake was positively associated with telomere length (tertile 1 vs. 2, coefficient [95% confidence interval] = 0.42 [0.12, 0.71]; tertile 1 vs. 3, coefficient [95% confidence interval] = 0.33 [0.04, 0.62]) after adjusting for covariates (age, BMI, passive smoking, and drinking). CONCLUSIONS: Our findings suggest that variation in vitamin A intake might influence telomere attrition in healthy individuals.

Effects chronic administration of corticosterone and estrogen on HPA axis activity and telomere length in brain areas of female rats.

Chronic stress is related to the acceleration of telomere shortening. Recent work showed a correlation between chronic psychosocial stress and reduced telomere length in certain cells. The exposure of T lymphocytes to cortisol promoted a significant reduction in telomerase activity. Although stress can promote changes in telomere length, whether increased glucocorticoid concentrations alter telomere length in brain tissue cells is unclear. In addition to modulating the activity of the stress system, estrogen also influences telomere length. The objective of this study was to verify whether chronic exposure to glucocorticoids promotes changes in the telomere length of encephalic areas involved in the control of HPA axis activity and whether estrogen affects these changes. Wistar rats were ovariectomized and treated with estradiol cypionate [(50 or 100 µg/kg, subcutaneously)] or oil and 20 mg/kg corticosterone or vehicle (isotonic saline with 2% Tween 80, subcutaneously) for 28 days. On the day after the end of the hormonal treatment, the animals were euthanized for collection of blood, brain and pituitary gland samples. Estrogen modulated the activity of the HPA axis. CRH, AVP and POMC mRNA levels were reduced by estrogen. At least in doses and treatment time used, there was no correlation between effects of exposure to glucocorticoids and estrogen on telomere length in the brain areas of female rats. However, estrogen treatment reduced the telomere length in the central amygdala and dorsal hippocampus, but not in the PVN, indicating a variation of reaction of telomeres for estrogen in different brain areas.

Pim1 maintains telomere length in mouse cardiomyocytes by inhibiting TGFß signalling.

AIMS: Telomere attrition in cardiomyocytes is associated with decreased contractility, cellular senescence, and up-regulation of proapoptotic transcription factors. Pim1 is a cardioprotective kinase that antagonizes the aging phenotype of cardiomyocytes and delays cellular senescence by maintaining telomere length, but the mechanism remains unknown. Another pathway responsible for regulating telomere length is the transforming growth factor beta (TGFß) signalling pathway where inhibiting TGFß signalling maintains telomere length. The relationship between Pim1 and TGFß has not been explored. This study delineates the mechanism of telomere length regulation by the interplay between Pim1 and components of TGFß signalling pathways in proliferating A549 cells and post-mitotic cardiomyocytes. METHODS AND RESULTS: Telomere length was maintained by lentiviral-mediated overexpression of PIM1 and inhibition of TGFß signalling in A549 cells. Telomere length maintenance was further demonstrated in isolated cardiomyocytes from mice with cardiac-specific overexpression of PIM1 and by pharmacological inhibition of TGFß signalling. Mechanistically, Pim1 inhibited phosphorylation of Smad2, preventing its translocation into the nucleus and repressing expression of TGFß pathway genes. CONCLUSION: Pim1 maintains telomere lengths in cardiomyocytes by inhibiting phosphorylation of the TGFß pathway downstream effectors Smad2 and Smad3, which prevents repression of telomerase reverse transcriptase. Findings from this study demonstrate a novel mechanism of telomere length maintenance and provide a potential target for preserving cardiac function.

Androgen derivatives improve blood counts and elongate telomere length in adult cryptic dyskeratosis congenita.

Dyskeratosis Congenita (DKC) is a systemic disorder caused by mutations resulting in impaired telomere maintenance. Clinical features include bone marrow failure and an increased risk of developing hematological malignancies. There are conflicting data whether androgen derivatives (AD) can elongate telomeres in vivo and whether AD treatment enhances the risk of gaining myelodysplastic syndrome-related mutations. Seven TERC or TERT-mutated DKC patients underwent AD treatment. All patients revealed hematological response. Telomere length of lymphocytes and granulocytes increased significantly and no MDS-related mutations were detected. Pending longer follow-up, treatment with AD seems to represent an efficient and safe therapy for DKC patients.

Telomere length is key to hepatocellular carcinoma diversity and telomerase addiction is an actionable therapeutic target.

BACKGROUND & AIMS: Telomerase activation is the earliest event in hepatocellular carcinoma (HCC) development. Thus, we aimed to elucidate the role of telomere length maintenance during liver carcinogenesis. METHODS: Telomere length was measured in the tumor and non-tumor liver tissues of 1,502 patients (978 with HCC) and integrated with TERT alterations and expression, as well as clinical and molecular (analyzed by genome, exome, targeted and/or RNA-sequencing) features of HCC. The preclinical efficacy of anti-TERT antisense oligonucleotides (ASO) was assessed in vitro in 26 cell lines and in vivo in a xenograft mouse model. RESULTS: Aging, liver fibrosis, male sex and excessive alcohol consumption were independent determinants of liver telomere attrition. HCC that developed in livers with long telomeres frequently had wild-type TERT with progenitor features and BAP1 mutations. In contrast, HCC that developed on livers with short telomeres were enriched in the non-proliferative HCC class and frequently had somatic TERT promoter mutations. In HCCs, telomere length is stabilized in a narrow biological range around 5.7 kb, similar to non-tumor livers, by various mechanisms that activate TERT expression. Long telomeres are characteristic of very aggressive HCCs, associated with the G3 transcriptomic subclass, TP53 alterations and poor prognosis. In HCC cell lines, TERT silencing with ASO was efficient in highly proliferative and poorly differentiated cells. Treatment for 3 to 16 weeks induced cell proliferation arrest in 12 cell lines through telomere shortening, DNA damage and activation of apoptosis. The therapeutic effect was also obtained in a xenograft mouse model. CONCLUSIONS: Telomere maintenance in HCC carcinogenesis is diverse, and is associated with tumor progression and aggressiveness. The efficacy of anti-TERT ASO treatment in cell lines revealed the oncogenic addiction to TERT in HCC, providing a preclinical rationale for anti-TERT ASO treatment in HCC clinical trials. LAY SUMMARY: Telomeres are repeated DNA sequences that protect chromosomes and naturally shorten in most adult cells because of the inactivation of the TERT gene, coding for the telomerase enzyme. Here we show that telomere attrition in the liver, modulated by aging, sex, fibrosis and alcohol, associates with specific clinical and molecular features of hepatocellular carcinoma, the most frequent primary liver cancer. We also show that liver cancer is dependent on TERT reactivation and telomere maintenance, which could be targeted through a novel therapeutic approach called antisense oligonucleotides.

The Association between Antidiabetic Agents and Leukocyte Telomere Length in the Novel Classification of Type 2 Diabetes Mellitus.

AIMS: This study aimed to explore the new role of telomere length (TL) in the novel classification of type 2 diabetes mellitus (T2DM) patients driven by cluster analysis. MATERIALS AND METHODS: A total of 541 T2DM patients were divided into 4 subgroups by k-means analysis: mild obesity-related diabetes (MOD), severe insulin-deficient diabetes (SIDD), severe insulin-resistant diabetes (SIRD), and mild age-related diabetes (MARD). After patients with insufficient data were excluded, further analysis was conducted on 246 T2DM patients. The TL was detected using telomere restriction fragment, and the related diabetic indexes were also measured by clinical standard procedures. RESULTS: The MARD group had significantly shorter TLs than the MOD and SIDD groups. Then, we subdivided all T2DM patients into the MARD and NONMARD groups, which included the MOD, SIDD, and SIRD groups. The TLs of the MARD group, associated with age, were discovered to be significantly shorter than those of the NONMARD group (p = 0.0012), and this difference in TL disappeared after metformin (p = 0.880) and acarbose treatment (p = 0.058). The linear analysis showed that metformin can more obviously reduce telomere shortening in the MARD group (r = 0.030, 95% CI 0.010-0.051, p = 0.004), and acarbose can more apparently promote telomere attrition in the SIRD group (r = -0.069, 95% CI -0.100 to -0.039, p< 0.001) compared with other T2DM patients after adjusting for age and gender. CONCLUSIONS: The MARD group was found to have shorter TLs and benefit more from the antiaging effect of metformin than other T2DM. Shorter TLs were observed in the SIRD group after acarbose use.

Telomere lengths in women treated for breast cancer show associations with chemotherapy, pain symptoms, and cognitive domain measures: a longitudinal study.

BACKGROUND: Survival rates for breast cancer (BC) have improved, but quality of life post-diagnosis/treatment can be adversely affected, with survivors reporting a constellation of psychoneurological symptoms (PNS) including stress, anxiety, depression, pain, fatigue, sleep disturbance, and cognitive dysfunction. METHODS: To assess a potential relationship between telomere length (TL) and the development/persistence of PNS, we longitudinally studied 70 women (ages 23-71) with early stage BC (I-IIIA) at 5 time-points: prior to treatment (baseline), the mid-point of their chemotherapy cycle, 6 months, 1 year, and 2 years following the initiation of chemotherapy. Measures quantified included assessments of each of the PNS noted above and TL [using both a multiplex qPCR assay and a chromosome-specific fluorescence in situ hybridization (FISH) assay]. RESULTS: Variables associated with qPCR mean TLs were age (p = 0.004) and race (T/S ratios higher in Blacks than Whites; p = 0.019). Significant differences (mostly decreases) in chromosome-specific TLs were identified for 32 of the 46 chromosomal arms at the mid-chemo time-point (p = 0.004 to 0.049). Unexpectedly, the sequential administration of doxorubicin [Adriamycin], cyclophosphamide [Cytoxan], and docetaxel [Taxotere] (TAC regimen) was consistently associated with higher TLs, when compared to TLs in women receiving a docetaxel [Taxotere], Carboplatin [Paraplatin], and trastuzumab [Herceptin] [TCH] chemotherapy regimen [association was shown with both the qPCR and FISH assays (p = 0.036)]. Of the PNS, pain was significantly negatively associated with TL (higher pain; shorter telomeres) for a subset of chromosomal arms (5q, 8p, 13p, 20p, 22p, Xp, Xq) (p = 0.014-0.047). Chromosomal TLs were also associated with 7 of the 8 cognitive domains evaluated, with the strongest relationship being noted for chromosome 17 and the visual memory domain (shorter telomeres; lower scores). CONCLUSIONS: We showed that race and age were significantly associated with telomere length in women treated for early stage BC and that acquired telomere alterations differed based on the woman's treatment regimen. Our study also demonstrated that pain and cognitive domain measures were significantly related to telomere values in this study cohort. Expanding upon the knowledge gained from this longitudinal study could provide insight about the biological cascade of events that contribute to PNS related to BC and/or its treatment.

Evaluation of telomere length and genotoxicity among asphalt associated workers.

There are contradictory reports about bitumen exposure and malignancy risk worldwide. Also, the evidence for genotoxicity risk among workers occupationally exposed to asphalt is insufficient. The study intended to evaluate particulate matter 10 (PM10) at the workplace and biomarkers of genotoxicity effects among a group of asphalt workers in and around Bangalore, India. This study involved a total of 107 participants (54 exposed group and 53 unexposed control group). To evaluate the genotoxicity, the urinary 8-OHdG and relative telomere length as oxidative damage while micronucleus (MN) assay for cytogenetic damage was carried out during the study. The majority of workers have reported health complaints and 57.4% of them were not using any personal protective equipments (PPE's). The level of PM10 detected was 104 ± 9.5 µg/m3 and 619 ± 22.7 µg/m3 in the road paving and asphalt mixing sites respectively. The biomonitoring study observed a highly significant (p = <0.001) increase in the level of 8-hydroxy-2-deoxyguanosine (8-OHdG) in the exposed group (23.17 ± 8.65 ng/mg creatinine) compared to the control (13.6 ± 7.12 ng/mg creatinine), revealed age significant associated and non-smoking borderline significant associated for oxidative stress. The relative telomere length (TL) analysis revealed its highly significant (p = 0.004) reduction in the exposed group, adjusted mean 0.95 (95% CI 0.83-1.07) compared to the control 1.06 (95% CI 0.91-1.26). The job category (p = 0.028), non-smoking (p = 0.026), and tobacco chewing (p = 0.013) were associated with reduced relative TL in the asphalt exposed group. In cytogenotoxicity analysis, the mean micronucleus (MN) frequency per 100 cells in the exposed group (26.46 ± 19.8) was significantly (p = <0.001) increased over the control group (8.56 ± 7.18). Neither smoking habit nor age appeared to influence the MN frequencies in either group. In the present study, we have demonstrated genetic damage in workers occupationally exposed to asphalt and particulate matter, raising concern for an increased risk of malignancy in these workers.

Shorter Leukocyte Telomere Length coupled with lower expression of Telomerase Genes in patients with Essential Hypertension.

Background: The essential hypertension (EH) pathophysiology remains poorly understood. Many studies indicate that reduced leukocyte telomere length (LTL) is involved in the EH pathogenesis, however, the direct analysis of arterial telomere length (ATL) from EH patients and normotensive individuals did not show a difference. To address these discrepant observations between LTL and ATL, we performed comprehensive analyses of LTL, telomerase gene expression and their genetic variants in healthy normotensive controls and EH patients. Methods: Sex-matched 206 EH patients and equal numbers of healthy controls were recruited. LTL, and the expression of two key telomerase components, telomerase reverse transcriptase (TERT) and internal RNA template (TERC) were determined using qPCR. Genetic variants of rs2736100 at the TERT and rs12696304 at the TERC loci were determined using TaqMan genotyping kits. Results: LTL was significantly shorter in EH patients than in their normotensive controls (0.96 ± 0.52 vs 1.19 ± 0.58, P = 0.001). Moreover, TERT and TERC expression in patients' leukocytes were substantially lower compare to that in healthy controls (TERT, 0.98 ± 0.98 vs 1.76 ± 1.75, P = 0.003; TERC, 1.26 ± 1.62 vs 4.69 ± 3.61, P < 0.001). However, there were no differences in the genetic variants of rs2736100 and rs12696304 between patient and control groups. Conclusions: EH patients have significantly shorter LTL, which may result from defective TERT and TERC expression in leukocytes. Collectively, lower telomerase expression contributes to shorter LTL observed in EH patients, and telomerase activators may be considered for EH therapy.

G-quadruplex ligands targeting telomeres do not inhibit HIV promoter activity and cooperate with latency reversing agents in killing latently infected cells.

Altered telomere maintenance mechanism (TMM) is linked to increased DNA damage at telomeres and telomere uncapping. We previously showed that HIV-1 latent cells have altered TMM and are susceptible to ligands that target G-quadruplexes (G4) at telomeres. Susceptibility of latent cells to telomere targeting could potentially be used to support approaches to eradicate HIV reservoirs. However, G4 ligands also target G-quadruplexes in promoters blocking gene transcription. Since HIV promoter sequence can form G-quadruplexes, we investigated whether G4 ligands interfere with HIV-1 promoter activity and virus reactivation from latency, and whether telomere targeting could be combined with latency reversing agents (LRAs) to promote elimination of HIV reservoirs. Our results indicate that Sp1 binding region in HIV-1 promoter can adopt G4 structures in duplex DNA, and that in vitro binding of Sp1 to G-quadruplex is blocked by G4 ligand, suggesting that agents targeting telomeres interfere with virus reactivation. However, our studies show that G4 agents do not affect HIV-1 promoter activity in cell culture, and do not interfere with latency reversal. Importantly, primary memory CD4 + T cells infected with latent HIV-1 are more susceptible to combined treatment with LRAs and G4 ligands, indicating that drugs targeting TMM may enhance killing of HIV reservoirs. Using a cell-based DNA repair assay, we also found that HIV-1 infected cells have reduced efficiency of DNA mismatch repair (MMR), and base excision repair (BER), suggesting that altered TMM in latently infected cells could be associated with accumulation of DNA damage at telomeres and changes in telomeric caps.

L-carnitine Extends the Telomere Length of the Cardiac Differentiated CD117+- Expressing Stem Cells.

Stem cell-based therapy has emerged as an attractive method for regenerating and repairing the lost heart organ. On other hand, poor survival and maintenance of the cells transferred into the damaged heart tissue are broadly accepted as serious barriers to enhance the efficacy of the regenerative therapy. For this reason, external factors, such as antioxidants are used as a favorite strategy by the investigators to improve the cell survival and retention properties. Therefore, the present study was conducted to investigate the In -vitro effect of L-carnitine (LC) on the telomere length and human telomerase reverse transcriptase (hTERT) gene expression in the cardiac differentiated bone marrow resident CD117+ stem cells through Wnt3/ß-catenin and ERK1/2 pathways. To do this, bone marrow resident CD117+ stem cells were enriched by the magnetic-activated cell sorting (MACS) method, and were differentiated to the cardiac cells in the absence (-LC) and presence of the LC (+LC). Also, characterization of the enriched c-kit+ cells was performed using the flow cytometry and immunocytochemistry. At the end of the treatment period, the cells were subjected to the real-time PCR technique along with western blotting assay for measurement of the telomere length and assessment of mRNA and protein, respectively. The results showed that 0.2 mM LC caused the elongation of the telomere length and increased the hTERT gene expression in the cardiac differentiated CD117+ stem cells. In addition, a significant increase was observed in the mRNA and protein expression of Wnt3, ß-catenin and ERK1/2 as key components of these pathways. It can be concluded that the LC can increase the telomere length as an effective factor in increasing the cell survival and maintenance of the cardiac differentiated bone marrow resident CD117+ stem cells via Wnt3/ß-catenin and ERK1/2 signaling pathway components.

The effects of aspirin and N-3 fatty acids on telomerase activity in adults with diabetes mellitus.

Type 2 Diabetes mellitus is associated with aging and shortened telomere length. Telomerase replaces lost telomeric repeats at the ends of chromosomes and is necessary for the replicative immortality of cells. Aspirin and the n3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are commonly used therapies in people with type 2 diabetes for reducing cardiovascular disease events, though their relation to telomerase activity is not well studied. We explored the effects of aspirin, EPA + DHA, and the combined effects of aspirin and EPA + DHA treatment on telomerase activity in 30 adults with diabetes mellitus. EPA and DHA ingestion alone increased telomerase activity then a decrease occurred with the addition of aspirin consumption. Crude (F-stat = 2.09, p = 0.13) and adjusted (F-stat = 2.20, p = 0.14) analyses of this decrease showed signs of a trend. These results suggest that aspirin has an adverse effect on aging in diabetics who have relatively high EPA and DHA ingestion.