Acute physical exercise and long-term individual shear rate therapy increase telomerase activity in human peripheral blood mononuclear cells

Exercise to combat cancer: focusing on the ends

Cancer remains a leading cause of death worldwide and although prognosis and survivorship after therapy have improved significantly, current cancer treatments have long-term health consequences. For decades telomerase-mediated telomere maintenance has been an attractive anti-cancer therapeutic target due to its abundance and role in telomere maintenance, pathogenesis, and growth in neoplasms. Telomere maintenance-specific cancer therapies, however, are marred by off-target side effects that must be addressed before they reach clinical practice. Regular exercise training is associated with telomerase-mediated telomere maintenance in normal cells, which is associated with healthy aging. A single bout of endurance exercise training dynamically, but temporarily, increases TERT mRNA and telomerase activity, as well as several molecules that control genomic stability and telomere length (i.e., shelterin and TERRA). Considering the epidemiological findings and accumulating research highlighting that exercise significantly reduces the risk of many types of cancers and the anti-carcinogenic effects of exercise on tumor growth in vitro, investigating the governing molecular mechanisms of telomerase control in context with exercise and cancer may provide important new insights to explain these findings. Specifically, the molecular mechanisms controlling telomerase in both healthy cells and tumors after exercise could reveal novel therapeutic targets for tumor-specific telomere maintenance and offer important evidence that may refine current physical activity and exercise guidelines for all stages of cancer care.

Aging Processes Are Affected by Energy Balance: Focused on the Effects of Nutrition and Physical Activity on Telomere Length

PURPOSE OF REVIEW

The number and proportion of individuals aged 60 and over are increasing globally. The increase in the elderly population has important social and economic effects. Telomere length is an important marker for healthy aging. Here, we review the relevance between telomere length and energy balance by determining the effects of physical activity, nutrients, dietary patterns, and foods on healthy aging and telomere length with related studies.

RECENT FINDINGS

Evidence emphasizes the importance of telomere length and integrity for healthy aging. It also focuses on the importance of potential interventions such as physical activity and a healthy diet to improve this process. We suggest that ensuring energy balance with regular physical activity and healthy diets can contribute to the aging process by protecting telomere length. In addition, different methods in studies, short and inconsistent durations, different types of exercise, different diet patterns, and non-standard foods have led to conflicting results. More studies are needed to elucidate molecular-based mechanisms.

Gene Therapy for Skin Aging

Extrinsic and intrinsic factors contribute to skin aging; nonetheless, they are intertwined. Moreover, intrinsic skin aging mirrors age-related declines in the entire human body's internal organs. There is evidence that skin appearance is an indicator of the general health of somebody or a visual certificate of health. Earlier, it was apparent that the intrinsic factors are unalterable, but the sparkling of skin aging gene therapy on the horizon is changing this narrative. Skin aging gene therapy offers tools for skin rejuvenation, natural beauty restoration, and therapy for diseases affecting the entire skin. However, skin aging gene therapy is an arduous and sophisticated task relying on precise interim stimulation of telomerase to extend telomeres and wend back the biological clock in the hopes to find the fountain of youth, while preserving cells innate biological features. Finding the hidden fountain of youth will be a remarkable discovery for promoting aesthetics medicine, genecosmetics, and healthy aging. Caloric restriction offers ultimate health benefits and a reproducible way to promote longevity in mammals, while delaying age-related diseases. Moreover, exercise further enhances these health benefits. This article highlights the potential of skin aging gene therapy and foretells the emerging dawn of the genecosmetics era.

Leukocyte telomere length and mitochondrial DNA copy number associate with endothelial function in aging-related cardiovascular disease

Background

We investigated the association between leukocyte telomere length, mitochondrial DNA copy number, and endothelial function in patients with aging-related cardiovascular disease (CVD).

Methods

In total 430 patients with CVD and healthy persons were enrolled in the current study. Peripheral blood was drawn by routine venipuncture procedure. Plasma and peripheral blood mononuclear cells (PBMCs) were collected. Cell-free genomic DNA (cfDNA) and leukocytic genomic DNA (leuDNA) were extracted from plasma and PBMCs, respectively. Relative telomere length (TL) and mitochondrial DNA copy number (mtDNA-CN) were analyzed using quantitative polymerase chain reaction. Endothelial function was evaluated by measuring flow-mediated dilation (FMD). The correlation between TL of cfDNA (cf-TL), mtDNA-CN of cfDNA (cf-mtDNA), TL of leuDNA (leu-TL), mtDNA-CN of leuDNA (leu-mtDNA), age, and FMD were analyzed based on Spearman's rank correlation. The association between cf-TL, cf-mtDNA, leu-TL, leu-mtDNA, age, gender, and FMD were explored using multiple linear regression analysis.

Results

cf-TL positively correlated with cf-mtDNA (r = 0.1834, P = 0.0273), and leu-TL positively correlated with leu-mtDNA (r = 0.1244, P = 0.0109). In addition, both leu-TL (r = 0.1489, P = 0.0022) and leu-mtDNA (r = 0.1929, P < 0.0001) positively correlated with FMD. In a multiple linear regression analysis model, both leu-TL (β = 0.229, P = 0.002) and leu-mtDNA (β = 0.198, P = 0.008) were positively associated with FMD. In contrast, age was inversely associated with FMD (β = -0.426, P < 0.0001).

Conclusion

TL positively correlates mtDNA-CN in both cfDNA and leuDNA. leu-TL and leu-mtDNA can be regarded as novel biomarkers of endothelial dysfunction.

The telomere regulatory gene POT1 responds to stress and predicts performance in nature: Implications for telomeres and life history evolution

Telomeres are emerging as correlates of fitness-related traits and may be important mediators of ecologically relevant variation in life history strategies. Growing evidence suggests that telomere dynamics can be more predictive of performance than length itself, but very little work considers how telomere regulatory mechanisms respond to environmental challenges or influence performance in nature. Here, we combine observational and experimental data sets from free-living tree swallows (Tachycineta bicolor) to assess how performance is predicted by the telomere regulatory gene POT1, which encodes a shelterin protein that sterically blocks telomerase from repairing the telomere. First, we show that lower POT1 gene expression in the blood was associated with higher female quality, that is, earlier breeding and heavier body mass. We next challenged mothers with an immune stressor (lipopolysaccharide injection) that led to "sickness" in mothers and 24 h of food restriction in their offspring. While POT1 did not respond to maternal injection, females with lower constitutive POT1 gene expression were better able to maintain feeding rates following treatment. Maternal injection also generated a 1-day stressor for chicks, which responded with lower POT1 gene expression and elongated telomeres. Other putatively stress-responsive mechanisms (i.e., glucocorticoids, antioxidants) showed marginal responses in stress-exposed chicks. Model comparisons indicated that POT1 mRNA abundance was a largely better predictor of performance than telomere dynamics, indicating that telomere regulators may be powerful modulators of variation in life history strategies.

Effects of Enhanced External Counterpulsation With Different Sequential Levels on Lower Extremity Hemodynamics

Objective: This study aimed to investigate acute hemodynamics of lower extremities during enhanced external counterpulsation with a three-level sequence at the hips, thighs, and calves (EECP-3), two-level sequence at the hips and thighs (EECP-2), and single leg three-level sequence (EECP-1).

Methods: Twenty healthy volunteers were recruited in this study to receive a 45-min EECP intervention. Blood flow spectrums in the anterior tibial artery, posterior tibial artery, and dorsalis pedis artery were imaged by Color Doppler ultrasound. Mean flow rate (FR), area, pulsatility index (PI), peak systolic velocity (PSV), end-diastolic velocity (EDV), mean flow velocity (MV), and systolic maximum acceleration (CCAs) were sequentially measured and calculated at baseline during EECP-3, EECP-1, and EECP-2.

Results: During EECP-3, PI, PSV, and MV in the anterior tibial artery were significantly higher, while EDV was markedly lower during EECP-1, EECP-2, and baseline (all P < 0.05). Additionally, ACCs were significantly elevated during EECP-3 compared with baseline. Moreover, FR in the anterior tibial artery was significantly increased during EECP-3 compared with baseline (P = 0.048). During EECP-2, PI and MV in the dorsalis pedis artery were significantly higher and lower than those at baseline, (both P < 0.05). In addition, FR was markedly reduced during EECP-2 compared with baseline (P = 0.028). During EECP-1, the area was significantly lower, while EDV was markedly higher in the posterior tibial artery than during EECP-1, EECP-2, and baseline (all P < 0.05). Meanwhile, FR of the posterior tibial artery was significantly reduced compared with baseline (P = 0.014).

Conclusion: Enhanced external counterpulsation with three-level sequence (EECP-3), EECP-2, and EECP-1 induced different hemodynamic responses in the anterior tibial artery, dorsalis pedis artery, and posterior tibial artery, respectively. EECP-3 acutely improved the blood flow, blood flow velocity, and ACCs of the anterior tibial artery. In addition, EECP-1 and EECP-2 significantly increased the blood flow velocity and peripheral resistance of the inferior knee artery, whereas they markedly reduced blood flow in the posterior tibial artery.

Effect of Physical Activity, Smoking, and Sleep on Telomere Length: A Systematic Review of Observational and Intervention Studies

Aging is a risk factor for several pathologies, restricting one’s health span, and promoting chronic diseases (e.g., cardiovascular and neurodegenerative diseases), as well as cancer. Telomeres are regions of repetitive DNA located at chromosomal ends. Telomere length has been inversely associated with chronological age and has been considered, for a long time, a good biomarker of aging. Several lifestyle factors have been linked with telomere shortening or maintenance. However, the consistency of results is hampered by some methodological issues, including study design, sample size, measurement approaches, and population characteristics, among others. Therefore, we aimed to systematically review the current literature on the effects of three relevant lifestyle factors on telomere length in human adults: physical activity, smoking, and sleep. We conducted a qualitative systematic review of observational and intervention studies using the Preferred Reporting Item for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The systematic literature search covered articles published in MEDLINE and EMBASE databases (from 2010 to 2020). A total of 1400 studies were identified; 83 were included after quality control. Although fewer sedentary activities, optimal sleep habits, and non- or ex-smoker status have been associated with less telomere shortening, several methodological issues were detected, including the need for more targeted interventions and standardized protocols to better understand how physical activity and sleep can impact telomere length and aging. We discuss the main findings and current limitations to gain more insights into the influence of these lifestyle factors on the healthy aging process.

Association of physical activity and nutrition with telomere length, a marker of cellular aging: A comprehensive review

The aging of the population has great social and economic effects because it is characterized by a gradual loss in physiological integrity, resulting in functional decline, thereby loss of ability to move independently. Telomeres, the hallmarks of biological aging, play a protective role in both cell death and aging. Critically short telomeres give rise to a metabolically active cell that is unable to repair damage or divide, thereby leading to aging. Lifestyle factors such as physical activity (PA) and nutrition could be associated with telomere length (TL). Indeed, regular PA and healthy nutrition as integral parts of our lifestyle can slow down telomere shortening, thereby delaying aging. In this context, the present comprehensive review summarizes the data from recent literature on the association of PA and nutrition with TL.

Exercise training increases telomerase reverse transcriptase gene expression and telomerase activity: A systematic review and meta-analysis

Telomeres protect genomic stability and shortening is one of the hallmarks of ageing. Telomerase reverse transcriptase (TERT) is the major protein component of telomerase, which elongates telomeres. Given that short telomeres are linked to a host of chronic diseases and the therapeutic potential of telomerase-based therapies as treatments and a strategy to extend lifespan, lifestyle factors that increase TERT gene expression and telomerase activity could attenuate telomere attrition and contribute to healthy biological ageing. Physical activity and maximal aerobic fitness are associated with telomere maintenance, yet the molecular mechanisms remain unclear. Therefore, the purpose of this systematic review and meta-analysis was to identify the influence of a single bout of exercise and long-term exercise training on TERT expression and telomerase activity. A search of human and rodent trials using the PubMed, Scopus, Science Direct and Embase databases was performed. Based on findings from the identified and eligible trials, both a single bout of exercise (n; standardised mean difference [95%CI]: 5; SMD: 1.19 [0.41-1.97], p = 0.003) and long-term exercise training (10; 0.31 [0.03-0.60], p = 0.03) up-regulates TERT and telomerase activity in non-cancerous somatic cells. As human and rodent studies were included in the meta-analyses both exhibited heterogeneity (I² = 55-87%, p < 0.05). Endurance athletes also exhibited increased leukocyte TERT and telomerase activity compared to their inactive counterparts. These findings suggest exercise training as an inexpensive lifestyle factor that increases TERT expression and telomerase activity. Regular exercise training could attenuate telomere attrition through a telomerase-dependent mechanism and ultimately extend health-span and longevity.

Effect of ACEI and ARB treatment on nitric oxide-dependent endothelial function

Background: Angiotensin-converting-enzyme inhibitors (ACEI) and angiotensin II receptor blockers (ARB) are widely used as a first-line therapy for the treatment of cardiovascular disease. Here, ACEI modulate the bradykinin receptor (BDKRB1 and BDKRB2) system and NO-dependent endothelial function, thus determining cardiovascular health and regenerative arteriogenesis. The current study aims at evaluating nitric oxide-dependent endothelial function, and gene expression of bradykinin receptors in peripheral blood mononuclear cells (PBMC) from patients with ACEI or ARB treatment. Patients and methods: The WalkByLab has been established to screen cardiovascular patients for peripheral artery disease and coronary artery disease. In total 177 patients from WalkByLab with heterogenous disease and risk status were randomly selected, divided according to their medication history into the following groups: 1. ACEI group, 2. ARB group or 3. non-ACE/ARB group. Total plasma nitrite/nitrate (NO) levels were measured, endothelial function was evaluated by assessing flow meditated dilation (FMD). PBMC were isolated from peripheral whole blood, and gene expression (qRT-PCR) of bradykinin receptors and angiotensin converting enzyme were assessed. Results: Plasma total NO concentration in the ACEI group (24.66±16.28, µmol/l) was increased as compared to the ARB group (18.57±11.58, µmol/l, P=0.0046) and non-ACE/ARB group (16.83±8.64, µmol/l, P=0.0127) in patients between 40 to 90 years of age. However, FMD values (%) in the ACEI group (7.07±2.40, %) were similar as compared to the ARB (6.35±2.13, %) and non-ACE/ARB group (6.51±2.15, %), but significantly negatively correlated with age. Interestingly, BDKRB1 mRNA level was significantly higher and BDKRB2 mRNA level lower in the ACEI group (BDKRB1 3.88-fold±1.05, BDKRB2 0.22-fold±0.04) as compared to the non-ACE/ARB group (BDKRB1 1.00-fold±0.39, P<0.0001, BDKRB2 1.00-fold±0.45, P=0.0136). Conclusions: ACEI treatment enhances total nitrite/nitrate concentration, furthermore, upregulates BDKRB1 in PBMC, but downregulates BDKRB2 mRNA expression. FMD is a strong determinant of vascular aging and is sensitive to underlying heterogenous cardiovascular diseases.

Expert consensus on the clinical application of enhanced external counterpulsation in elderly people (2019)

Enhanced external counterpulsation (EECP) is a non-invasive assisted circulation technique and a rich pool of evidence has accumulated for its clinical application in the prevention and management of multiple comorbidities in the elderly population, including angina, heart failure, ischemic cerebrovascular diseases, neurodegenerative diseases, sleep disorder, diabetes and its complications, ischemic eye diseases, sudden hearing loss and erectile dysfunction, as well as various psychological and psychiatric conditions. When applying EECP to elderly patients, emphasis should be placed on issues such as safety assessment, risk management and protocol individualization, as well as the monitoring of efficacy during and after treatment.

Biomechanical Forces and Atherosclerosis: From Mechanism to Diagnosis and Treatment

The article provides an overview of current views on the role of biomechanical forces in the pathogenesis of atherosclerosis. The importance of biomechanical forces in maintaining vascular homeostasis is considered. We provide descriptions of mechanosensing and mechanotransduction. The roles of wall shear stress and circumferential wall stress in the initiation, progression and destabilization of atherosclerotic plaque are described. The data on the possibilities of assessing biomechanical factors in clinical practice and the clinical significance of this approach are presented. The article concludes with a discussion on current therapeutic approaches based on the modulation of biomechanical forces.

Stress and immunosenescence: The role of telomerase

Chronic stress is associated with the accelerated aging of the immune system and represents a potent risk factor for the development and progression of a wide range of physical and mental disorders. The elucidation of molecular pathways and mechanisms underlying the link between stress and cellular aging is an area of considerable interest and investigation. In this context, telomere biology has emerged as a particularly attractive candidate mechanism. Several studies have linked immune cell telomere length with stress-related conditions and states, and also with several physical and mental disorders. Because the cellular reverse transcriptase enzyme telomerase is the primary regulator of telomere length (by adding telomeric DNA to telomeres and thereby attenuating telomere shortening), the understanding of its regulation and regulatory functions constitutes a prime target for developing strategies to prevent, attenuate or reverse the adverse consequences of immune system aging (immunosenescence). In this review we provide an overview of the mechanistic pathways linking telomerase with stress and cellular aging, with an emphasis on the immune system. We summarize and synthesize the current state of the literature on immune cell telomerase in different stress- and aging-related disease states and provide recommendations for future research directions.

Characterization in humans of in vitro leucocyte maximal telomerase activity capacity and association with stress

The goal of this study was to develop and validate a measure of maximal telomerase activity capacity (mTAC) for use in human studies of telomere biology, and to determine its association with measures of stress and stress responsivity. The study was conducted in a population of 28 healthy young women and men who were assessed serially across two separate days, at multiple time points, and in response to a standardized laboratory stressor. Venous blood was collected at each of these multiple assessments, and an in vitro mitogen challenge (phytohaemagglutinin supplemented with interleukin-2) was used to stimulate telomerase activity in leucocytes. After first establishing the optimal post-stimulation time course to characterize mTAC, we determined the within-subject stability and the between-subject variability of mTAC. The major findings of our study are as follows: (i) the optimal time point to quantify human leucocyte mTAC appears to be at 72 h after mitogen stimulation; (ii) mTAC exhibits substantial within-subject stability (correlations were in the range of r 0.68-0.82) and between-subject variability, with a high intra-class coefficient (0.70), indicating greater between-subject relative to within-subject variability; (iii) mTAC is not influenced by situational factors including time of day, cortisol, acute stress exposure and immune cell distribution in the pre-stimulation blood sample; and (iv) a significant proportion of the between-subject variability in mTAC is associated with measures of stress and stress responsivity (mTAC is lower in subjects reporting higher levels of perceived (chronic) stress and exhibiting higher psychophysiological stress reactivity). Based collectively on these findings, it appears that mTAC, as proposed and operationalized, empirically meets the key criteria to represent a potentially useful individual difference measure of telomerase activity capacity of human leucocytes.This article is part of the theme issue 'Understanding diversity in telomere dynamics'.

Differential effects of endurance, interval, and resistance training on telomerase activity and telomere length in a randomized, controlled study

Aims

It is unknown whether different training modalities exert differential cellular effects. Telomeres and telomere-associated proteins play a major role in cellular aging with implications for global health. This prospective training study examines the effects of endurance training, interval training (IT), and resistance training (RT) on telomerase activity and telomere length (TL).

Methods and results

One hundred and twenty-four healthy previously inactive individuals completed the 6 months study. Participants were randomized to three different interventions or the control condition (no change in lifestyle): aerobic endurance training (AET, continuous running), high-intensive IT (4 × 4 method), or RT (circle training on 8 devices), each intervention consisting of three 45 min training sessions per week. Maximum oxygen uptake (VO2max) was increased by all three training modalities. Telomerase activity in blood mononuclear cells was up-regulated by two- to three-fold in both endurance exercise groups (AET, IT), but not with RT. In parallel, lymphocyte, granulocyte, and leucocyte TL increased in the endurance-trained groups but not in the RT group. Magnet-activated cell sorting with telomerase repeat-ampliflication protocol (MACS-TRAP) assays revealed that a single bout of endurance training-but not RT-acutely increased telomerase activity in CD14+ and in CD34+ leucocytes.

Conclusion

This randomized controlled trial shows that endurance training, IT, and RT protocols induce specific cellular pathways in circulating leucocytes. Endurance training and IT, but not RT, increased telomerase activity and TL which are important for cellular senescence, regenerative capacity, and thus, healthy aging.

Physical Activity and Nutrition: Two Promising Strategies for Telomere Maintenance?

As the world demographic structure is getting older, highlighting strategies to counteract age-related diseases is a major public health concern. Telomeres are nucleoprotein structures that serve as guardians of genome stability by ensuring protection against both cell death and senescence. A hallmark of biological aging, telomere health is determined throughout the lifespan by a combination of both genetic and non-genetic influences. This review summarizes data from recently published studies looking at the effect of lifestyle variables such as nutrition and physical activity on telomere dynamics.

Telomeres, Aging and Exercise: Guilty by Association?

Telomeres are repetitive tandem DNA sequences that cap chromosomal ends protecting genomic DNA from enzymatic degradation. Telomeres progressively shorten with cellular replication and are therefore assumed to correlate with biological and chronological age. An expanding body of evidence suggests (i) a predictable inverse association between telomere length, aging and age-related diseases and (ii) a positive association between physical activity and telomere length. Both hypotheses have garnered tremendous research attention and broad consensus; however, the evidence for each proposition is inconsistent and equivocal at best. Telomere length does not meet the basic criteria for an aging biomarker and at least 50% of key studies fail to find associations with physical activity. In this review, we address the evidence in support and refutation of the putative associations between telomere length, aging and physical activity. We finish with a brief review of plausible mechanisms and potential future research directions.

Preliminary evidence that age and sex affect exercise-induced hTERT expression

The ability to repair cellular damage is reduced with aging, resulting in cellular senescence. Telomeres shorten as cells divide but the rate of telomere attrition is modulated by telomerase, an enzyme that adds nucleotides to the chromosome. Shelterin is a protein complex that acts as a negative regulator of telomerase. The aim of the present study was to investigate age-related differences in telomerase and shelterin responses to acute exercise. We hypothesized that acute exercise would stimulate an increased activity of telomerase (measured by telomerase reverse transcriptase, hTERT) without an increase in activity of shelterin (measured by telomeric repeat binding factor 2, TRF2) in both young and older individuals and that hTERT response would be attenuated in older individuals. Young (22±2y, n=11) and older (60±2y, n=8) men and women performed 30min of cycling. Blood was collected pre-exercise and 30, 60, and 90-min post-exercise. The trial induced a significant hTERT response in the cohort as a whole (p<0.05) with greater increases in the young as compared to the older group (time-by-group interaction p<0.05). As expected, TRF2 did not change in response to the trial, however older individuals had a higher TRF2 response at 60min (p<0.05). There was an unexpected sex difference, regardless of age, where men had significantly greater hTERT and TRF2 responses to the acute exercise as compared to women (p<0.05). These data support the hypothesis that aging is associated with attenuated telomerase activation in response to high-intensity exercise; however, this was only evident in men.

Acute exercise activates p38 MAPK and increases the expression of telomere-protective genes in cardiac muscle

NEW FINDINGS

What is the central question of this study? A positive association between telomere length and exercise training has been shown in cardiac tissue of mice. It is currently unknown how each bout of exercise influences telomere-length-regulating proteins. We sought to determine how a bout of exercise altered the expression of telomere-length-regulating genes and a related signalling pathway in cardiac tissue of mice. What is the main finding and its importance? Acute exercise altered the expression of telomere-length-regulating genes in cardiac tissue and might be related to altered mitogen-activated protein kinase signalling. These findings are important in understanding how exercise provides a cardioprotective phenotype with ageing. Age is the greatest risk factor for cardiovascular disease. Telomere length is shorter in the hearts of aged mice compared with young mice, and short telomere length has been associated with an increased risk of cardiovascular disease. One year of voluntary wheel-running exercise attenuates the age-associated loss of telomere length and results in altered gene expression of telomere-length-maintaining and genome-stabilizing proteins in heart tissue of mice. Understanding the early adaptive response of the heart to an endurance exercise bout is paramount to understanding the impact of endurance exercise on heart tissue and cells. To this end, we studied mice before (BL), immediately after (TP1) and 1 h after a treadmill running bout (TP2). We measured the changes in expression of telomere-related genes (shelterin components), DNA-damage-sensing (p53 and Chk2) and DNA-repair genes (Ku70 and Ku80) and mitogen-activated protein kinase (MAPK) signalling. The TP1 animals had increased TRF1 and TRF2 protein and mRNA levels, greater expression of DNA-repair and -response genes (Chk2 and Ku80) and greater protein content of phosphorylated p38 MAPK compared with both BL and TP2 animals. These data provide insights into how physiological stressors remodel the heart tissue and how an early adaptive response mediated by exercise may be maintaining telomere length and/or stabilizing the heart genome through the upregulation of telomere-protective genes.