Geroprotector drugs and exercise: friends or foes on healthy longevity?

Biomarkers of aging: from molecules and surrogates to physiology and function

Many countries face an unprecedented challenge in aging demographics. This has led to an exponential growth in research on aging, which, coupled to a massive financial influx of funding in the private and public sectors, has resulted in seminal insights into the underpinnings of this biological process. However, critical validation in humans has been hampered by the limited translatability of results obtained in model organisms, additionally confined by the need for extremely time-consuming clinical studies in the ostensible absence of robust biomarkers that would allow monitoring in shorter time frames. In the future, molecular parameters might hold great promise in this regard. In contrast, biomarkers centered on function, resilience, and frailty are available at the present time, with proven predictive value for morbidity and mortality. In this review, the current knowledge of molecular and physiological aspects of human aging, potential antiaging strategies, and the basis, evidence, and potential application of physiological biomarkers in human aging are discussed.

Rapamycin does not compromise physical performance or muscle hypertrophy after PoWeR while intermittent rapamycin alleviates glucose disruptions by frequent rapamycin

An increasing number of physically active adults are taking the mTOR inhibitor rapamycin off label with the goal of extending healthspan. However, frequent rapamycin dosing disrupts metabolic health during sedentary conditions and abates the anabolic response to exercise. Intermittent once weekly rapamycin dosing minimizes many negative metabolic side effects of frequent rapamycin in sedentary mice. However, it remains unknown how different rapamycin dosing schedules impact metabolic, physical, and skeletal muscle adaptations to voluntary exercise training. Therefore, we tested the hypothesis that intermittent rapamycin (2mg/kg; 1x/week) would avoid detrimental effects on adaptations to 8 weeks of progressive weighted wheel running (PoWeR) in adult female mice (5-month-old) by evading the sustained inhibitory effects on mTOR signaling by more frequent dosing schedules (2mg/kg; 3x/week). Frequent but not intermittent rapamycin suppressed skeletal muscle mTORC1 signaling in PoWeR trained mice. PoWeR improved maximal exercise capacity, absolute grip strength, and myofiber hypertrophy with no differences between vehicle or rapamycin treated mice. Conversely, frequent and intermittent rapamycin treated mice had impaired glucose tolerance and insulin sensitivity compared to vehicle treated mice after PoWeR; however, intermittent rapamycin reduced the impact on glucose intolerance versus frequent rapamycin. Collectively, these data in adult female mice suggest that 1) rapamycin is largely compatible with the physical and skeletal muscle benefits of PoWeR and 2) the detrimental effects of rapamycin on body composition and glucose metabolism in the context of voluntary exercise may be reduced by intermittent dosing.

The Fifth Annual Symposium of the Midwest Aging Consortium

As the healthcare burden caused by an increasingly aging population rapidly rises, a pressing need exists for innovative geroscience research that can elucidate aging mechanisms and precipitate the development of therapeutic interventions to support healthy aging. The Fifth Annual Midwest Aging Consortium Aging Research symposium, held from April 28 to 30, 2024, was hosted by The Ohio State University in Columbus, Ohio, and featured presentations from investigators across the Midwestern United States. This report summarizes the research presented at the symposium, whose topics included cellular senescence and the aging brain, metabolism and metabolic interventions, nutrition, redox mechanisms and biomarkers, and stress mechanisms. Abstract presentations and short talks highlighted early-stage and young investigators, whereas 2 keynote presentations anchored the symposium. Overall, this symposium showed the robustness of aging research in the Midwest and underscored the advantages of a collaborative approach to geroscience research.

Long COVID as a disease of accelerated biological aging: An opportunity to translate geroscience interventions

It has been four years since long COVID-the protracted consequences that survivors of COVID-19 face-was first described. Yet, this entity continues to devastate the quality of life of an increasing number of COVID-19 survivors without any approved therapy and a paucity of clinical trials addressing its biological root causes. Notably, many of the symptoms of long COVID are typically seen with advancing age. Leveraging this similarity, we posit that Geroscience-which aims to target the biological drivers of aging to prevent age-associated conditions as a group-could offer promising therapeutic avenues for long COVID. Bearing this in mind, this review presents a translational framework for studying long COVID as a state of effectively accelerated biological aging, identifying research gaps and offering recommendations for future preclinical and clinical studies.

Amino acid restriction, aging, and longevity: an update

Various so-called dietary restriction paradigms have shown promise for extending health and life. All such paradigms rely on ad libitum (hereafter ad lib) feeding, something virtually never employed in animals whose long-term health we value, either as a control or, except for food restriction itself, for both control and treatment arms of the experiment. Even though the mechanism(s) remain only vaguely understood, compared to ad lib-fed animals a host of dietary manipulations, including calorie restriction, low protein, methionine, branched-chain amino acids, and even low isoleucine have demonstrable health benefits in laboratory species in a standard laboratory environment. The remaining challenge is to determine whether these health benefits remain in more realistic environments and how they interact with other health enhancing treatments such as exercise or emerging geroprotective drugs. Here we review the current state of the field of amino acid restriction on longevity of animal models and evaluate its translational potential.

Unraveling Histone Loss in Aging and Senescence

As the global population experiences a notable surge in aging demographics, the need to understand the intricate molecular pathways exacerbated by age-related stresses, including epigenetic dysregulation, becomes a priority. Epigenetic mechanisms play a critical role in driving age-related diseases through altered gene expression, genomic instability, and irregular chromatin remodeling. In this review, we focus on histones, a central component of the epigenome, and consolidate the key findings of histone loss and genome-wide redistribution as fundamental processes contributing to aging and senescence. The review provides insights into novel histone expression profiles, nucleosome occupancy, disruptions in higher-order chromatin architecture, and the emergence of noncanonical histone variants in the aging cellular landscape. Furthermore, we explore the current state of our understanding of the molecular mechanisms of histone deficiency in aging cells. Specific emphasis is placed on highlighting histone degradation pathways in the cell and studies that have explored potential strategies to mitigate histone loss or restore histone levels in aging cells. Finally, in addressing future perspectives, the insights gained from this review hold profound implications for advancing strategies that actively intervene in modulating histone expression profiles in the context of cellular aging and identifying potential therapeutic targets for alleviating a multitude of age-related diseases.