Oxidative stress, telomeres and cellular senescence: What non-drug interventions might break the link?

Telomeres are higher order structures that cap and protect chromosome ends. Telomeric DNA naturally shortens during somatic cell division and as a result of oxidative stress. Excessive shortening disrupts the integrity of the telomere, causing cellular senescence, one of the hallmarks of organismal ageing. The accumulation of senescent cells with ageing contributes to the loss of tissue homeostasis and the development of age-related pathologies. Hence, counteracting telomere shortening may be one relevant approach to develop strategies for healthier ageing. In this review I present the case for the existence of a link between oxidative stress, accelerated telomere shortening and cellular senescence. I also examine findings from human observational studies exploring associations between telomere length and oxidative stress-related parameters. Finally, I discuss results from randomised control trials testing the impact of non-pharmacological lifestyle interventions on the maintenance of telomere length, considering the potential mechanisms that might be involved

Short sleep duration is associated with shorter telomere length in healthy men: findings from the Whitehall II cohort study.

Shorter telomere length and poor sleep are more prevalent at older ages, but their relationship is uncertain. This study explored associations between sleep duration and telomere length in a sample of healthy middle and early old age people

Evaluation of economic effectiveness of the state purchases system : criteria and priorities

The purpose of the article is to develop new criteria and priorities of evaluating the economic effectiveness of the state purchases system in modern Russia. The methodology of the work consists of the general scientific methods (induction, deduction, formalization, synthesis, etc.) and specific methods of the economic theory. The authors conduct the problem analysis of the methodology of evaluation of economic effectiveness of the state purchases system which is applied in modern Russia and analyze the causal connections of its application in practice, as well as conduct the comparative analysis of this methodology and the specially developed proprietary method that allows eliminating the determined problems of the existing methodology. The authors conduct the criterial evaluation of economic effectiveness of the state purchases system in Russia with the specially developed method and conclude that the effectiveness of the state purchases system in modern Russia is high due to a large per cent of economy of budget assets, domination of orders for domestic products within the import substitution policy, stimulation of economic growth, and increase of the society’s well-being. Perspectives of further growth of its effectiveness according to the offered criteria and priorities are related to simplification of the procedures of applicants’ participation in auctions for stimulating their competition, increase of the share of electronic orders, and moderate reduction of the average sum of order.peer-reviewe

COVID-19 and chronological aging : senolytics and other anti-aging drugs for the treatment or prevention of corona virus infection?

COVID-19, also known as SARS-CoV-2, is a new emerging zoonotic corona virus of the SARS (Severe Acute Respiratory Syndrome) and the MERS (Middle East Respiratory Syndrome) family. COVID-19 originated in China and spread world-wide, resulting in the pandemic of 2020. For some reason, COVID-19 shows a considerably higher mortality rate in patients with advanced chronological age. This begs the question as to whether there is a functional association between COVID-19 infection and the process of chronological aging. Two host receptors have been proposed for COVID-19. One is CD26 and the other is ACE-2 (angiotensin-converting enzyme 2). Interestingly, both CD26 and the angiotensin system show associations with senescence. Similarly, two proposed therapeutics for the treatment of COVID-19 infection are Azithromycin and Quercetin, both drugs with significant senolytic activity. Also, Chloroquine-related compounds inhibit the induction of the well-known senescence marker, Beta-galactosidase. Other anti-aging drugs should also be considered, such as Rapamycin and Doxycycline, as they behave as inhibitors of protein synthesis, blocking both SASP and viral replication. Therefore, we wish to speculate that the fight against COVID-19 disease should involve testing the hypothesis that senolytics and other anti-aging drugs may have a prominent role in preventing the transmission of the virus, as well as aid in its treatment. Thus, we propose that new clinical trials may be warranted, as several senolytic and anti-aging therapeutics are existing FDA-approved drugs, with excellent safety profiles, and would be readily available for drug repurposing efforts. As Azithromycin and Doxycycline are both commonly used antibiotics that inhibit viral replication and IL-6 production, we may want to consider this general class of antibiotics that functionally inhibits cellular protein synthesis as a side-effect, for the treatment and prevention of COVID-19 disease

The use of the soluble receptor for advanced glycation-end products (sRAGE) as a potential biomarker of disease risk and adverse outcomes

The soluble receptor for advanced glycation end-products (sRAGE) has been classically considered a sink for pro-inflammatory RAGE ligands and as such has been associated with protection from inflammatory stress and disease. An alternative, though not mutually exclusive view is that high levels of sRAGE in circulation reflect the overstimulation of cell surface RAGE which if persistent, lead to the amplification of pro-inflammatory processes and the exacerbation of pathological states. With these two scenarios in mind this review focuses on the potential role of sRAGE as a prospective biomarker of disease risk and adverse outcomes

The angiotensin-(1-7)/Mas receptor a xis protects from endothelial cell senescence via klotho and Nrf2 activation

Endothelial cell senescence is a hallmark of va scular aging that pre disposes to vascular disease. We aimed to explore the capacity of the renin-angiotensin system (RAS) heptapeptide angiotensin (Ang)-(1-7) to counteract human endothelial cell senescence and to identify intracellular pathways mediati ng its potential protective action. In human umbilical vein endothelial cell (HUVEC) cult ures, Ang II promoted cell senescence, as revealed by the enhancement in se nescence-associated galactosidase (SA- -gal+) positive staining, total and telomeric DNA damage, adhesion molecules expression and human mononuclear adhesion to HUVEC monolaye rs. By activating the G-coupled receptor Mas, Ang-(1-7) inhibit ed the pro-senescence action of Ang II, but also of a non- RAS stressor such as the cytokine IL-1 . Moreover, Ang-(1-7) enhanced endothelial klotho levels, while klotho silencing resulted in th e loss of the anti-senescence action of the heptapeptide. Indeed, both Ang-(1-7) and recombinant klotho activated the cytoprotective Nrf2/heme-oxygenase-1 (HO)-1 pathway. The HO-1 inhibitor tin protoporphyrin IX prevented the anti-senescence action evoked by Ang-(1-7) or recombinant klotho. Overall, the present study ide ntifies Ang-(1-7) as an anti-senescence peptide displaying its protectiv e action beyond the RAS by consecutively activating klotho and Nrf2/HO-1. Ang-(1-7) mimetic dru gs may thus prove useful to prevent endothelial cell senescence and its re lated vascular complications

Highlights of the 2nd International Symposium on Tribbles and Diseases: Tribbles tremble in therapeutics for immunity, metabolism, fundamental cell biology and cancer

The Tribbles (TRIB) family of pseudokinase proteins has been shown to play key roles in cell cycle, metabolic diseases, chronic inflammatory disease, and cancer development. A better understanding of the mechanisms of TRIB pseudokinases could provide new insights for disease development and help promote TRIB proteins as novel therapeutic targets for drug discovery. At the 2nd International Symposium on Tribbles and Diseases held on May 7‒9, 2018 in Beijing, China, a group of leading Tribbles scientists reported their findings and ongoing studies about the effects of the different TRIB proteins in the areas of immunity, metabolism, fundamental cell biology and cancer. Here, we summarize important and insightful overviews from 4 keynote lectures, 13 plenary lectures and 8 short talks that took place during this meeting. These findings may offer new insights for the understanding of the roles of TRIB pseudokinases in the development of various diseases

Low dose cranial irradiation-induced cerebrovascular damage is reversible in mice

BACKGROUND: High-dose radiation-induced blood-brain barrier breakdown contributes to acute radiation toxicity syndrome and delayed brain injury, but there are few data on the effects of low dose cranial irradiation. Our goal was to measure blood-brain barrier changes after low (0.1 Gy), moderate (2 Gy) and high (10 Gy) dose irradiation under in vivo and in vitro conditions. METHODOLOGY: Cranial irradiation was performed on 10-day-old and 10-week-old mice. Blood-brain barrier permeability for Evans blue, body weight and number of peripheral mononuclear and circulating endothelial progenitor cells were evaluated 1, 4 and 26 weeks postirradiation. Barrier properties of primary mouse brain endothelial cells co-cultured with glial cells were determined by measurement of resistance and permeability for marker molecules and staining for interendothelial junctions. Endothelial senescence was determined by senescence associated β-galactosidase staining. PRINCIPLE FINDINGS: Extravasation of Evans blue increased in cerebrum and cerebellum in adult mice 1 week and in infant mice 4 weeks postirradiation at all treatment doses. Head irradiation with 10 Gy decreased body weight. The number of circulating endothelial progenitor cells in blood was decreased 1 day after irradiation with 0.1 and 2 Gy. Increase in the permeability of cultured brain endothelial monolayers for fluorescein and albumin was time- and radiation dose dependent and accompanied by changes in junctional immunostaining for claudin-5, ZO-1 and β-catenin. The number of cultured brain endothelial and glial cells decreased from third day of postirradiation and senescence in endothelial cells increased at 2 and 10 Gy. CONCLUSION: Not only high but low and moderate doses of cranial irradiation increase permeability of cerebral vessels in mice, but this effect is reversible by 6 months. In-vitro experiments suggest that irradiation changes junctional morphology, decreases cell number and causes senescence in brain endothelial cells

The longitudinal relationship between cortisol responses to mental stress and leukocyte telomere attrition

Context: Chronic psychological stress has been associated with shorter telomeres in some studies, but the underlying mechanisms are poorly understood. One possibility is that the neuroendocrine responses associated with stress exposure are involved. Objective: To testing the hypothesis that greater cortisol responsivity to acute stressors predicts more rapid telomere attrition. Design: We measured salivary cortisol responses to two challenging behavioral tasks. Leukocyte telomere length was measured at the time of mental stress testing and 3 years later. Participants: We studied 411 initially healthy men and women aged 54-76 years. Main outcome measure: Leukocyte telomere length. Results: Cortisol responses to this protocol were small, we divided participants into cortisol responders (n = 156) and non-responders (n = 255) using a criterion (≥20%) previously shown to predict increases in cardiovascular disease risk. There was no significant association between cortisol responsivity and baseline telomere length, although cortisol responders tended to have somewhat shorter telomeres (β = -0.061, standard error 0.049). But cortisol responders had shorter telomeres and more rapid telomere attrition than non-responders on follow-up, after controlling statistically for age, gender, socioeconomic status, smoking, time of day of stress testing and baseline telomere length (β = -0.10, standard error 0.046, p = 0.029). The association was maintained after additional control for cardiovascular risk factors (β = -0.11, p = 0.031). The difference between cortisol responders and non-responders was equivalent to approximately 2 years in aging. Conclusions: These findings suggest that cortisol responsivity may mediate in part the relationship between psychological stress and cellular aging

Short sleep duration is associated with shorter telomere length in healthy men: findings from the Whitehall II cohort study

Background: Shorter telomere length and poor sleep are more prevalent at older ages, but their relationship is uncertain. This study explored associations between sleep duration and telomere length in a sample of healthy middle and early old age people. Methods: Participants were 434 men and women aged 63.3 years on average drawn from the Whitehall II cohort study. Sleep duration was measured by self-report. Results: There was a linear association between sleep duration and leukocyte telomere length in men but not in women (P = 0.035). Men reporting shorter sleep duration had shorter telomeres, independently of age, body mass index, smoking, educational attainment, current employment, cynical hostility scores and depressive symptoms. Telomeres were on average 6% shorter in men sleeping 5 hours or fewer compared with those sleeping more than 7 hours per night. Conclusion: This study adds to the growing literature relating sleep duration with biomarkers of aging, and suggests that shortening of telomeres might reflect mechanisms through which short sleep contributes to pathological conditions in older men