Low Telomerase Activity Research Articles

Telomerase activity, mTert gene expression and the telomere length in mouse mesenchymal stem cells in the late period after γ- and γ,n-irradiation and in the tumors developed from these cells

In proliferating normal and tumor cells, the telomere length (TL) is maintained by high telomerase activity (TA). In the absence of TA the TL maintenance involves a mechanism of alternative lengthening of telomeres (ALT). The aim of this study was to investigate the level of TA, the mTert expression and TL in cultured normal and transformed by γ- and γ,n-irradiation mesenchymal stem cells (MSCs) from mouse bone marrow, in sarcomas that developed after the transplantation of these cells into syngeneic mice, and in fibrosarcoma cell lines obtained from these tumors to find out the role of AT or ALT in maintaining TL in these cells. During prolonged cultivation of normal and transformed under the influence of γ- (1 Gy and 6 Gy) and γ,n-irradiation (0.05 Gy, 0.5 Gy, and 2 Gy) MSCs from mouse bone marrow, a decrease in TA was detected in irradiated cells. Even deeper decrease in TA was found in sarcomas developed after administration of transformed MSCs to syngeneic mice and in fibrosarcoma cell lines isolated from these tumors in which TA was either absent or was found to be at a very low level. TL in three of the four lines obtained was halved compared to the initial MSCs. With absent or low TA and reduced TL, the cells of all the obtained fibrosarcoma lines successfully proliferated without signs of a change in survival. The mechanism of telomere maintainance in fibrosarcoma cell lines in the absence of TA needs further investigation and it can be assumed that it is associated with the use of the ALT. The detected decrease or absence of TA in transformed under the action of irradiation MSCs with the preservation or even an increase in the telomerase gene expression may be associated with the formation of inactive splicing variants, and requires further study. The obtained lines of transformed MSCs and fibrosarcomas with TA and without the activity of this enzyme can be a useful model for studying the efficacy of TA and ALT inhibitors in vitro and in vivo.

Study of the diagnostic significance of telomere length and telomerase activity in patients with cerebral atherosclerosis and type 2 diabetes mellitus

Cerebrovascular diseases areamongst the most important causes of morbidity and mortality in adult population. Objective — to determine the relationship between telomere length and telomerase activity with lipid spectrum, structural and functional status of the heart and cerebral vessels and heart rate variability in patients with cerebral atherosclerosis (CA) of stages 1—3and type 2 diabetes mellitus. Materials and methods. In a comprehensive clinical and instrumental study, 161 patients with CA 1—3stages were included. Telomerase activity was determined using a real-time tandem repeat amp­lification protocol. The relative lengths of telomeres were measured using multiplex quantitative poly­merase chain reaction in real time. Results and discussion. Patients were divided into 2 groups: 1 — with CA ofstage 1-2, 2 — with CA of stage 3 (with history of ischemic atherothrombotic stroke — AS). Mean age = 65.1 ± 10.5 and 65.4 ± 9.1 years, respectively. The percentage of men was 21.2 % in group1 and 52 % in the group 2. To identify factors that influence telomere size as a marker of early aging, the method of constructing logistic regression models was used. In building the models, the following categories were used: shorter telomere length — T/S < 2.61 (lowest and middle tercile); longer telomere length — T/S over 2.61. For selection of a set of significant risk factors, the method of step-by-step inclusion/exclusion of signs was used withexclusion threshold p > 0.15 and inclusion threshold p < 0.03. A multivariate logistic regression model was built on the identified significant risk factors. A statistically significant positive relationship was established between the telomere length and the E/A (diastolic function of the heart) and LPVLD, as well as negative relationships with the EF and the intima-media complex (IMC) on the right. To identify factors affecting telomerase activity, the method of constructing logistic regression models was used. In building the models, the following categories were used: lower telomerase activity — T/S < 3.16 (lowest and middle terciles); higher telomerase activity — T/S above 3.16. A sta­­tistically significant positive correlation of telomerase activity with the total stress index of the vegetative regulation HRV was also established, as well as a negative correlation with the atherogenic index. Conclusions. Telomere length and telomerase activity are comparable in elderly patients with CA of stage 1—2 and history of ischemic atherothrombotic stroke, including type 2 diabetes mellitus. Based on a multifactor regression analysis, the relationship between telomeres length and LPVLD, IMC, EF and LV diastolic function was detected in patients at different stages of CA, includingtype 2 diabetes (AUC 0.79; CI 0.69—0.87). Based on multivariate regression analysis the association of telomerase activity with atherogenic index and total stress index of vegetative regulation of heart rhythm was revealed in patients at different stages of CA, including type 2 diabetes (AUC 0.73; 95 % CI 0.63—0.83).

Relationship between telomerase activity and parameters of carbohydrate metabolism and vascular wall

Aim. To study the relationship between telomerase activity and parameters of carbohydrate metabolism and vascular wall depending on the type 2 diabetes (T2D). Material and methods. The study included 50 patients with T2D and 139 healthy volunteers. All subjects were assessed for carbohydrate metabolism, chronic inflammation (C-reactive protein (CRP), fibrinogen), endothelial dysfunction, carotid intima-media thickness and number of atherosclerotic plaques by duplex scanning, carotid-femoral pulse wave velocity, lymphocyte telomere length and telomerase activity. Results. In T2D patients, telomerase activity was lower (p=0,039), telomeres were shorter (p=0,031) and CRP level was higher (p=0,031) than in patients without T2D. All patients were divided by telomerase activity. T2D patients with low telomerase activity had higher values of CRP ( р =0,016), pulse wave velocity ( р =0,010), carotid intima-media thickness ( р &lt;0,001) and number of atherosclerotic plaques ( р =0,014) than in patients without T2D. There were no significant differences in high telomerase activity group. In the group of patients with/without T2D, there were independent negative relationship between telomerase activity and glycated hemoglobin (p=0,035), fasting plasma glucose (p=0,003), arterial stiffness (p=0,044) and independent positive relationship between telomerase activity and fibrinogen (p=0,027), CRP (p=0,042). Conclusion. Vascular changes, chronic inflammation and cell aging were weightier in patients with T2D. The established relationship between telomerase activity and parameters of carbohydrate metabolism, chronic inflammation and vascular stiffness may indicate the important role of telomerase activity in the development of cardiovascular diseases in T2D patients.

Spheroid-Derived Cells From Renal Adenocarcinoma Have Low Telomerase Activity and High Stem-Like and Invasive Characteristics.

Cancer stem cells (CSCs) are a theorized small subpopulation of cells within tumors thought to be responsible for metastasis, tumor development, disease progression, treatment-resistance, and recurrence. The identification, isolation, and biological characterization of CSCs may therefore facilitate the development of efficient therapeutic strategies targeting CSCs. This study aims to compare the biology and telomerase activity of CSCs to parental cells (PCs) in renal cancer. Renal CSCs were enriched from the ACHN cell line using a sphere culture system. Spheroid-derived cells (SDCs) and their adherent counterparts were compared with respect to their colony and sphere formation, expression of putative CSC markers, tumorigenicity in non-obese diabetic/severe combined immunodeficiency (NOD/SCID) mice, and invasiveness. The expression of genes associated with CSCs, stemness, EMT, apoptosis, and ABC transporters was also compared between the two populations using quantitative real-time PCR (qRT-PCR). Finally, telomerase activity, hTERT expression, and sensitivity to MST-312, a telomerase inhibitor, was investigated between the two populations. We demonstrated that a subpopulation of ACHN cells was capable of growing as spheroids with many properties similar to CSCs, including higher clonogenicity, superior colony- and sphere-forming ability, and stronger tumorigenicity and invasiveness. In addition, SDCs demonstrated a higher expression of markers for CSCs, stemness, EMT, apoptosis, and ABC transporter genes compared to PCs. The expression of hTERT and telomerase activity in SDCs was significantly lower than PCs; however, the SDC population was more sensitive to MST-312 compared to PCs. These findings indicate that the SDC population exhibits stem-like potential and invasive characteristics. Moreover, the reduced expression of hTERT and telomerase activity in SDCs demonstrated that the expressions of hTERT and telomerase activity are not always higher in CSCs. Our results also showed that MST-312 treatment inhibited SDCs more strongly than PCs and may therefore be useful as a complementary targeted therapy against renal CSCs in the future.

Telomerase activity in the differential diagnosis of pancreatic mass.

In this manuscript, we show that the detection of telomerase activity in pancreatic mass tissue provides early evidence of a cancerous process that requires a well-timed surgical treatment. Eighty-eight patients with pancreatic mass (both benign and malignant) were involved in the research. Comparative analyses of the data and instrumental methods to define the histological structure of tumor mass and measure telomerase activity have been carried out. Intense telomerase activity (+++) in the tissue of pancreatic mass determines cancer with high accuracy. One hundred percent of patients with pancreatic cancer had high telomerase activity. In 32.4% of patients with average telomerase activity (++) pancreatic cancer was diagnosed. The average telomerase activity (++) in pancreatic tumors gives an early indication of pancreatic cancer and requires dynamic observation for 6 to 12 months (P<0.05). Low telomerase activity (+) in patients with benign tumors is an accurate sign for confirming a diagnosis. The detection of telomerase activity in pancreatic mass tissue provides early evidence of a cancerous process that requires a well-timed surgical treatment.

RELATIONSHIP OF TELOMERE LENGTH, TELOMERASE ACTIVITY, AND OXIDATIVE STRESS MARKERS IN PATIENTS WITH CEREBRAL ATHEROSCLEROSIS AND TYPE 2 DIABETES

The aim of study is to determine the relationship between telomere length and telomerase activity with indicators of oxidative stress in patients with stage 1-3 cerebral atherosclerosis and type 2 diabetes.&#x0D; Material and methods. A total clinical and instrumental study involved 161 patients with grade 1–3 CA. Telomerase activity was determined using a tandem repeat amplification protocol with real-time detection. The relative telomere lengths were measured using real-time multiplex quantitative polymerase chain reaction.&#x0D; Results. A comparative analysis revealed that patients with stage 1-3 CA with long telomeres had a significantly higher catalase level than in the short telomere group, and the catalase and SOD levels in the group with high telomerase activity were significantly lower than in the group with low telomerase activity. A correlation analysis revealed significant direct relationships between telomere length and oxidative stress markers such as catalase and SOD (r = 0.23 and r = 0.21, respectively) and telomerase activity with GSH (r = 0.48). An inverse relationship between the telomere length and T2DM (r = -0.21) was also revealed. Telomere length and telomerase activity were not correlated with other markers of oxidative stress.&#x0D; Conclusion. In patients with stage 1-3 cerebral atherosclerosis, an association of some markers of oxidative stress (catalase, SOD, GSH) with telomere length and telomerase activity, regardless of the presence of concomitant type 2 diabetes mellitus, was revealed. In patients with stage 1-3 cerebral atherosclerosis with longer telomeres, catalase levels are statistically significantly higher than in patients with short telomeres. Stage 1-3 cerebral atherosclerosis patients with higher telomerase activity are characterized by statistically significantly lower levels of catalase and superoxide dismutase compared with patients with lower telomerase activity. The most stable direct correlation in this category of patients was found between GSH and telomerase activity (r = 0.48), which may indicate the key role of GSH in the rate of telomere shortening and the development of atherosclerosis.

Rescue from Stx2-Producing E.coli-Associated Encephalopathy by Intravenous Injection of Muse Cells in NOD-SCID Mice.

Shiga toxin-producing Escherichia coli (STEC) causes hemorrhagic colitis, hemolytic uremic syndrome, and acute encephalopathies that may lead to sudden death or severe neurologic sequelae. Current treatments, including immunoglobulin G (IgG) immunoadsorption, plasma exchange, steroid pulse therapy, and the monoclonal antibody eculizumab, have limited effects against the severe neurologic sequelae. Multilineage-differentiating stress-enduring (Muse) cells are endogenous reparative non-tumorigenic stem cells that naturally reside in the body and are currently under clinical trials for regenerative medicine. When administered intravenously, Musecells accumulate to the damaged tissue, where they exert anti-inflammatory, anti-apoptotic, anti-fibrotic, and immunomodulatory effects, and replace damaged cells by differentiating into tissue-constituent cells. Here, severely immunocompromised non-obese diabetic/severe combined immunodeficiency (NOD-SCID) mice orally inoculated with 9 × 109 colony-forming units of STEC O111 and treated 48 h later with intravenous injection of 5 × 104 Muse cells exhibited 100% survival and no severe after-effects of infection. Suppression of granulocyte-colony-stimulating factor (G-CSF) by RNAi abolished the beneficial effects of Muse cells, leading to a 40% death and significant body weight loss, suggesting the involvement of G-CSF in the beneficial effects of Muse cells in STEC-infected mice. Thus, intravenous administration of Muse cells could be a candidate therapeutic approach for preventing fatal encephalopathy after STEC infection.

Cognitive frailty among Malaysian older adults: baseline findings from the LRGS TUA cohort study.

PurposeThis study was aimed at determining the presence of cognitive frailty and its associated factors among community-dwelling older adults from the “LRGS-Towards Useful Aging (TUA)” longitudinal study.Patients and methodsThe available data related to cognitive frailty among a sub-sample of older adults aged 60 years and above (n=815) from two states in Malaysia were analysed. In the LRGS-TUA study, a comprehensive interview-based questionnaire was administered to obtain the socio-demographic information of the participants, followed by assessments to examine the cognitive function, functional status, dietary intake, lifestyle, psychosocial status and biomarkers associated with cognitive frailty. The factors associated with cognitive frailty were assessed using a bivariate logistic regression (BLR).ResultsThe majority of the older adults were categorized as robust (68.4%), followed by cognitively pre-frail (37.4%) and cognitively frail (2.2%). The data on the cognitively frail and pre-frail groups were combined for comparison with the robust group. A hierarchical BLR indicated that advancing age (OR=1.04, 95% CI:1.01–1.08, p<0.05) and depression (OR=1.49, 95% CI:1.34–1.65, p<0.001) scored lower on the Activity of Daily Living (ADL) scale (OR=0.98, 95% CI:0.96–0.99, p<0.05), while low social support (OR=0.98, 95% CI:0.97–0.99, p<0.05) and low niacin intake (OR=0.94, 95% CI:0.89–0.99, p<0.05) were found to be significant factors for cognitive frailty. Higher oxidative stress (MDA) and lower telomerase activity were also associated with cognitive frailty (p<0.05).ConclusionOlder age, a lower niacin intake, lack of social support, depression and lower functional status were identified as significant factors associated with cognitive frailty among older Malaysian adults. MDA and telomerase activity can be used as potential biomarkers for the identification of cognitive frailty.

Telomerase Plays a Pivotal Role in Collateral Growth Under Ischemia by Suppressing Age-Induced Oxidative Stress, Expression of p53, and Pro-Apoptotic Proteins.

Aging is not only a major risk factor for impaired collateral growth under ischemia but also shortens the telomere length, which is regulated by telomerase. We examined the role of telomerase activity during impaired collateral growth during aging in ischemic skeletal muscle. Unilateral hind limb ischemia was generated in old, young, and old mice chronically administered a telomerase activator. In old mice, blood flow recovery and capillary density development in ischemic hind limbs were reduced compared to those in young mice, and these changes were restored to equal levels by administration of TA-65, a telomerase activator. During the early phase of ischemic muscle changes in old mice, telomerase reverse transcriptase expression and telomerase activity were both low compared to those in young mice and old mice treated with TA-65. Levels of reactive oxygen species (ROS), DNA double-strand breaks, and expression of p53, p16, and Bax/Bcl-2 were all elevated in ischemic muscles of old mice compared to those in the muscles of young mice and old mice treated with TA-65 treatment; these factors were maintained at low levels equivalent to those seen in young mice during the experiment. Expression of HIF1α/vascular endothelial growth factor (VEGF) and PGC1α were decreased in old mice compared to those in young mice and old mice treated with TA-65. Collateral growth under ischemic conditions is impaired in aged animals due to low telomerase activity, increased ROS, resultant DNA damage, and expression of tumor suppressor and pro-apoptotic proteins. These data suggest that telomerase activation enhances collateral growth and rescues ischemic tissue in old individuals.

Coexistence of obstructive sleep apnea and telomerase activity, concentration of selected adipose tissue hormones and vascular endothelial function in patients with arterial hypertension.

The aim of the present study was to determine the effect of obstructive sleep apnea (OSA) with hypertension on telomerase activity, visfatin and adipsine concentration in the blood and vascular endothelial function assessed by ultrasound measured flow-mediated dilatation of the brachial artery (FMD). The study involved a group of 106 people (average age: 54.79 years). The determination of telomerase activity and blood visfatin and adipsine concentrations, brachial artery ultrasound examination with endothelium-dependent dilatation evaluation (FMD) and polysomnography were carried out. Patients with hypertension without OSA were characterized by significantly greater FMD in comparison to patients with arterial hypertension and OSA (8.13 ± 5.12 %vs. 6.82 ± 5.36%; p < 0.05). Negative linear relationship between apnea-hypopnea index (AHI) and FMD (r = -0.22, p < 0.05) has been demonstrated. Negative linear relationship between adipsine concentration in the blood and length of REM (Rapid Eye Movement) sleep (r = -0.21, p < 0.05) was found. Positive linear relationship between the concentration of visfatin in the blood and the length of REM sleep (r = 0.22, p < 0.05) was also observed. Higher body mass index, higher total cholesterol, triglyceride and glucose levels have been shown to be independent predictors of higher AHI values, while greater telomerase activity, greater FMD and use of angiotensin converting enzyme inhibitors are independent predicators for lower AHI values. Higher values of AHI index in polysomnography in hypertensive patients can be related to lower telomerase activity in the blood and impaired function of vascular endothelial function assessed using ultrasound.

Nörofibromatozis tip1 hastalarında telomeraz aktivitesi

Purpose: In various studies low telomerase activity have been shown to have a protective role in some types of cancer. Patients with neurofibromatosis type-1 (NF1) are at risk of developing certain types of cancer. Prognosis is generally better in patients with NF1 than those without NF1. In the present study, we aimed to measure telomerase activity in patients with NF1 and in controls.Materials and Methods: Telomerase activity was investigated in peripheral blood samples with human telomerase reverse transcriptase (hTERT) mRNA by using real time reverse transcriptase polymerase chain reaction (RT-PCR) method and Light Cycler 480 system.Results: hTERT expression was investigated in blood samples of 48 patients with a diagnosis of NF1 and in 37 controls. Telomerase activity was positive in 36 of 48 (75%) patients with NF1 and 23 of 37 patients (73%) without NF1. Telomerase activity was positive in 31 of 36 patients (86%) with NF1 having a benign or malignant tumor, whereas it was positive in 5 of 12 NF1 patients (41.6%) without a tumor. Conclusion: Detection of hTERT expression in patients with NF1 can be used as a useful marker for tumorigenesis. Additional studies need to be done to know whether detection of hTERT expression in low-grade tumors would help predict progression to high-grade tumors.

Cognitive performance in survivors of breast cancer and markers of biological aging.

Biological aging pathways accelerated by cancer treatments may be a mechanism for cognitive impairment in cancer survivors. The goal of the current study was to examine whether indicators of biological aging, namely elevated levels of DNA damage, reduced telomerase enzymatic activity, and shorter peripheral blood mononuclear cell (PBMC) telomere length (TL) would be related to cognitive function in a cohort of survivors of breast cancer. The authors evaluated a cross-sectional sample of 94 women aged 36 to 69 years who were treated for early-stage breast cancer 3 to 6 years previously. Leukocyte DNA damage, PBMC telomerase enzymatic activity, PBMC TL, and the inflammatory marker soluble tumor necrosis factor receptor II (sTNF-RII) were determined from blood samples. Cognitive function was assessed using a neuropsychological test battery and self-report. Linear regression models examined the relationship between biological aging predictors and cognitive outcomes. Both higher DNA damage and lower telomerase were found to be statistically significantly related to lower executive function scores adjusting for age, body mass index, race, years from treatment, and intelligence score (standardized coefficients [B], -0.23 and 0.30; all P values <.05). In addition, lower telomerase activity was associated with worse attention and motor speed scores (B values, 0.30 and 0.24; P &lt;.05). sTNF-RII and TL were found to be unrelated to any of the neurocognitive domains. The results of the current study suggest a significant association between measures of biological aging and objective measures of cognitive performance in survivors of breast cancer. Future prospective studies are needed to confirm a causal role of biological aging as a driver of declines in cognitive function after cancer treatment.

Effects of Meditation and Music-Listening on Blood Biomarkers of Cellular Aging and Alzheimer's Disease in Adults with Subjective Cognitive Decline: An Exploratory Randomized Clinical Trial.

Telomere length (TL), telomerase activity (TA), and plasma amyloid-β (Aβ) levels have emerged as possible predictors of cognitive decline and dementia. To assess the: 1) effects of two 12-week relaxation programs on TL, TA, and Aβ levels in adults with subjective cognitive decline; and 2) relationship of biomarker changes to those in cognitive function, psychosocial status, and quality of life (QOL). Participants were randomized to a 12-week Kirtan Kriya meditation (KK) or music listening (ML) program and asked to practice 12 minutes/day. Plasma Aβ(38/40/42) and peripheral blood mononuclear cell TL and TA were measured at baseline and 3 months. Cognition, stress, sleep, mood, and QOL were assessed at baseline, 3 months, and 6 months. Baseline blood samples were available for 53 participants (25 KK, 28 ML). The KK group showed significantly greater increases in Aβ40 than the ML group. TA rose in both groups, although increases were significant only among those with higher practice adherence and lower baseline TA. Changes in both TL and TA varied by their baseline values, with greater increases among participants with values ≤50th percentile (ps-interaction <0.006). Both groups improved in cognitive and psychosocial status (ps ≤0.05), with improvements in stress, mood, and QOL greater in the KK group. Rising Aβ levels were correlated with gains in cognitive function, mood, sleep, and QOL at both 3 and 6 months, associations that were particularly pronounced in the KK group. Increases in TL and TA were also correlated with improvements in certain cognitive and psychosocial measures. Practice of simple mind-body therapies may alter plasma Aβ levels, TL, and TA. Biomarker increases were associated with improvements in cognitive function, sleep, mood, and QOL, suggesting potential functional relationships.

Assessment of telomerase activity in leukocytes of type 2 diabetes mellitus patients having or not foot ulcer: Possible correlation with other clinical parameters.

Telomerase is the enzyme that maintains telomere length by adding telomeric repeats after each cell division. Numerous metabolic factors such as obesity, insulin resistance or physical inactivity have been associated with shortened telomeres. In the present study, we assessed telomerase activity in diabetic patients having or not foot ulcer. A total of 90 adult patients with type 2 diabetes mellitus (T2DM) were studied. Patients were allocated into two groups according to the absence or presence of active foot ulcers as follows: Νon-ulcer group (N=58) and ulcer group (N=32). Our data revealed that the patients with diabetic ulcers had significantly greater waist circumference and neuropathy disability score, while exhibiting lower telomerase activity, indicating the possible existence of a common clinical profile among ulcer-bearing diabetic patients. Validation of our findings by extending the study in larger patient groups may contribute to the understanding of T2DM pathophysiology and its main clinical implications.

Влияние дексаметазона на процессы активации и созревания CD3CD4CD45RO Т-клеток при ревматоидном артрите in vitro

Цель - исследование влияния глюкокортикоида дексаметазона (Dex) на процессы активации и генерации терминально-дифференцированных эффекторных CD4 Т-лимфоцитов (T) в культурах CD3CD45RO Т-клеток в условиях, имитирующих стимуляцию Т-клеточного рецептора in vitro в норме и при ревматоидном артрите (РА). Методика. Исследовали мононуклеарные лейкоциты (МНК) из венозной гепаринизированной крови 50 пациентов с ревматоидным артритом. Методом проточной цитофлюориметрии проанализировано изменение иммунофенотипа Т-лимфоцитов; иммуноферментным анализом оценена секреция CD3CD45RO Т-клетками цитокина IL-2; методом полимеразной цепной реакции определена экспрессия мРНК генов hTERT, U2af1l4 и Gfi1 в CD3CD45RO Т-клетках. Результаты. Полученные данные демонстрируют, что in vitro на фоне TCR-активации CD3CD45RO культур Т-клеток, Dex (в разной степени выраженности) участвует в формировании субпопуляции терминально-дифференцированных эффекторов (CD3CD4CD45ROCD28 T), характеризующихся низкой теломеразной активностью, потерей молекул костимуляции (CD28) и активации (CD25) и реэкспрессирующих высокомолекулярную изоформу рецептора CD45 - CD45RA в норме и у больных РА. Заключение. Сделано заключение, что популяция CD3CD4CD45ROCD28 лимфоцитов является ключевым участником в патогенезе РА, ускоренно приобретающая свой негативный потенциал на фоне глюкокортикоидной терапии, способствуя прогрессии заболевания, в частности, за счет мощного выброса провоспалительных медиаторов. Aim. To study the effect of dexamethasone (Dex) on activation and generation of terminally differentiated effector CD4 T-lymphocytes (TEMRA) in cultured CD3CD45RO T cells under the conditions mimicking stimulation of the T-cell receptor in vitro as it occurs in health and rheumatoid arthritis (RA). Methods. The study was performed on mononuclear leukocytes isolated from heparinized venous blood of 50 patients with rheumatoid arthritis. Changes in the T-lymphocyte immunophenotype were detected using flow cytofluorometry. Secretion of cytokine IL-2 by CD3 CD45ROT cells was assessed by ELISA. Expression of hTERT, U2af1l4, and Gfi1 gene mRNA in CD3CD45RO T cells was measured by polymerase chain reaction. Results. During the in vitro TCR activation of cultured CD3CD45RO T cells, Dex participated to a variable extent in formation of a subpopulation of terminally differentiated effectors (CD3CD4CD45ROCD28 TEMRA), which are characterized by low telomerase activity, loss of costimulation (CD28) and activation (CD25) molecules, and re-expression of the high molecular weight CD45-CD45RA receptor isoform both in healthy individuals and RA patients. Conclusion. The population of CD3CD4CD45ROCD28 lymphocytes is a key participant in the pathogenesis of RA by accelerating their negative impact during the glucocorticoid therapy. This lymphocyte population contributes to RA progression particularly due to the powerful discharge of proinflammatory mediators.

Biomarkers of aging associated with past treatments in breast cancer survivors

Radiation and chemotherapy are effective treatments for cancer, but are also toxic to healthy cells. Little is known about whether prior exposure to these treatments is related to markers of cellular aging years later in breast cancer survivors. We examined whether past exposure to chemotherapy and/or radiation treatment was associated with DNA damage, telomerase activity, and telomere length 3–6 years after completion of primary treatments in breast cancer survivors (stage 0–IIIA breast cancer at diagnosis). We also examined the relationship of these cellular aging markers with plasma levels of Interleukin (IL)-6, soluble TNF-receptor-II (sTNF-RII), and C-reactive protein (CRP). Ninety-four women (36.4–69.5 years; 80% white) were evaluated. Analyses adjusting for age, race, BMI, and years from last treatment found that women who had prior exposure to chemotherapy and/or radiation compared to women who had previously received surgery alone were more likely to have higher levels of DNA damage (P = .02) and lower telomerase activity (P = .02), but did not have differences in telomere length. More DNA damage and lower telomerase were each associated with higher levels of sTNF-RII (P’s < .05). We found that exposure to chemotherapy and/or radiation 3–6 years prior was associated with markers of cellular aging, including higher DNA damage and lower telomerase activity, in post-treatment breast cancer survivors. Furthermore, these measures were associated with elevated inflammatory activation, as indexed by sTNF-RII. Given that these differences were observed many years after the treatment, the findings suggest a long lasting effect of chemotherapy and/or radiation exposure.

Effect of a qigong intervention on telomerase activity of Chinese women survivors of intimate partner violence: a single-blind, waitlist, randomised controlled trial

BackgroundAccelerated cellular ageing, shown as lower telomerase activity, might be responsible for the well documented adverse health outcomes of intimate partner violence such as increased risk of cardiovascular diseases and depression. Mind-body interventions such as qigong are thought to be effective in alleviating accelerated cellular ageing but evidence of effectiveness is scarce. This study aimed to test the effect of a qigong intervention on telomerase activity of Chinese women who have experienced intimate partner violence. MethodsWe did this assessor-blind, waitlist, randomised controlled trial in the HKSKH Lady MacLehose Centre, a community centre located in one of the 18 districts in Hong Kong. Chinese women meeting the inclusion criteria (aged 18–55 years and abused by an intimate partner) were randomly assigned (1:1) by computer-generated blocked randomisation to either the intervention group or the control group. The intervention group received a 5·5-month qigong intervention provided by a qigong master assisted by trained project workers. The waitlist control group received the same training but after the intervention group had completed the intervention. The primary outcome was change in telomerase activity measured by telomerase level in peripheral blood mononuclear cells obtained at baseline and on completion of the intervention, and it was analysed with a TeloTAGGG telomerase PCR ELISA kit. Adopting the principle of intention to treat, we used a mixed-effects model to analyse adjusted telomerase activity. Ethical approval was obtained from the Institutional Review Board of the University of Hong Kong/Hospital Authority Hong Kong West Cluster (Reference number UW12–555, Jan 9, 2013). All participants provided written informed consent. This trial is registered with ClinicalTrials.gov, number NCT02060123. FindingsBetween March 12, 2014, and May 26, 2016, we enrolled 271 participants of whom 136 were assigned to the intervention group and 135 to the control group. 247 (91%) participants completed the intervention (attrition 9%). Telomerase activity increased significantly in intervention group (from 186·93 to 265·86, relative unit to internal standard, p=0·015) but not in the control group (from 251·57 to 241·16, p=0·742), and the group × time interaction effect was significant (p=0·049). InterpretationEvidence from the study may inform the use of mind-body interventions for alleviating accelerated cellular ageing in abused Chinese women. Strengths of the study include robust study design, objective biomarkers, and low attrition while the short follow-up is among the limitations. FundingHealth and Medical Research Fund awarded by the Food and Health Bureau of the Hong Kong SAR Government.

Cellular aging dynamics after acute malaria infection: A 12-month longitudinal study.

SummaryAccelerated cellular aging and reduced lifespan have recently been shown in birds chronically infected with malaria parasites. Whether malaria infection also affects cellular aging in humans has not been reported. Here, we assessed the effect of a single acute Plasmodium falciparum malaria infection on cellular aging dynamics in travelers prospectively followed over one year in Sweden. DNA and RNA were extracted from venous blood collected at the time of admission and repeatedly up to one year. Telomere length was measured using real‐time quantitative PCR, while telomerase activity and CDKN2A expression were measured by reverse transcriptase (RT)–qPCR. Our results show that acute malaria infection affects cellular aging as reflected by elevated levels of CDKN2A expression, lower telomerase activity, and substantial telomere shortening during the first three months postinfection. After that CDKN2A expression declined, telomerase activity increased and telomere length was gradually restored over one year, reflecting that cellular aging was reversed. These findings demonstrate that malaria infection affects cellular aging and the underlying cellular mechanism by which pathogens can affect host cellular aging and longevity need to be elucidated. Our results urge the need to investigate whether repeated malaria infections have more pronounced and long‐lasting effects on cellular aging and lifespan (similarly to what was observed in birds) in populations living in malaria endemic areas.

Telomere length is short in PCOS and oral contraceptive does not affect the telomerase activity in granulosa cells of patients with PCOS.

Our study aimed to investigate the association of telomerase activity (TA) and telomere length (TL) in granulosa cells (GCs) with IVF outcomes of polycystic ovary syndrome (PCOS) patients, and the effects of oral contraceptive pill (OCP) pretreatment on these two parameters. One hundred sixty-three infertile women were enrolled and divided into a PCOS group (n=65) and a non-PCOS group (n=98). The PCOS group was further divided into an OCP pretreatment group (n=35) and a non-OCP pretreatment group (n=30), a TA <0.070 group (n=34) and a TA ≥0.070 group (n=31), and a TL <1 group (n=41) and a TL ≥1 group (n=24), respectively. No obvious differences were observed in TA between these groups. The TL was 0.971 in PCOS group and 1.118 in non-PCOS group (P=0.005). The patients with TL ≥1 accounted for 36.9% in PCOS group and 54.1% in non-PCOS group (P=0.032). The average duration of infertility for PCOS patients was 5years in TA <0.070 group and 4years in TA ≥0.070 group (P=0.038), and 5years in TL <1 group and 3years in TL ≥1 group (P=0.006), respectively. No obvious differences were observed in IVF outcomes between these groups. No obvious differences were observed in TA, TL, or IVF outcomes between OCP pretreatment group and non-OCP pretreatment group in PCOS patients. Shorter TL was found in PCOS patients. The TA levels did not change significantly in PCOS patients. PCOS patients with a lower TA level and shorter telomeres had an earlier onset of infertility symptoms. No predictive value was found for TA and TL in terms of embryo quality or IVF outcomes in PCOS patients, and no effect OCP pretreatment was observed on either TA and TL.

Identification of an RNA aptamer binding hTERT-derived peptide and inhibiting telomerase activity in MCF7 cells.

Human telomerase reverse transcriptase is an essential rate-limiting component of telomerase complex. hTERT protein in association with other proteins and the human telomerase RNA (hTR) shows telomerase activity, essential for maintaining genomic integrity in proliferating cells. hTERT binds hTR through a decapeptide located in the RID2 (RNA interactive domain 2) domain of N-terminal region. Since hTERT is essential for telomerase activity, inhibitors of hTERT are of great interest as potential anti-cancer agent. We have selected RNA aptamers against a synthetic peptide from the RID2 domain of hTERT by employing in vitro selection protocol (SELEX). The selected RNAs could bind the free peptide, as CD spectra suggested conformational change in aptamer upon RID2 binding. Extracts of cultured breast cancer cells (MCF7) expressing this aptamer showed lower telomerase activity as estimated by TRAP assay. hTERT-binding RNA aptamers hold promise as probable anti-cancer therapeutic agent.