Longevity Papers

To investigate how physical activity (PA) volume, intensity, duration, and fragmentation are associated with the risk of all-cause and cardiovascular disease mortality. To produce centile curves for PA volume and intensity representative of US adults.

Susan B. Levin argues that the human confidence that an ageless body would be better is irrational. She offers a Kantian-inspired argument to show that human understanding cannot rationally access the experiences of a post-human and ageless existence. We challenge this rationale with a three-step argument: first, an ageless body does not have to be post-human. One should distinguish between the transhumanist projects of life extension and accounts focused on enhancing well-being and quality of life. An existence without aging does not require a radical change in one's temporal intuitions, which makes rational discussion possible. Second, we defend that biological aging does not entail any valuable goods. These goods refer to the chronological dimension of aging. Finally, we argue that biological aging is indeed negative and one may need biotechnological interventions in aging to achieve internal transcendence. Thus, we rationally argue that an ageless body would be better.

The concept of frailty, now being adopted in most medical disciplines, is attracting growing interest in neurology. Every day, most neurologists care for patients with varying degrees of frailty, from very mild to very severe. Frailty exacerbates patients' health needs, complicates clinical decision making, and negatively affects their health outcomes. Increasing evidence suggests that frailty affects the risk, clinical presentation, and course of common age-related neurological disorders, including dementia, Parkinson's disease, stroke, and multiple sclerosis. Most neurologists should become familiar with assessing and measuring frailty. Doing so can provide information that is crucial for diagnosis, prognostication, and care planning. Consideration of frailty can help to elucidate the pathophysiological underpinnings of age-related neurological disorders, clarify the clinical validity and utility of candidate biomarkers, and identify novel therapeutic targets. Randomised controlled trials investigating late-life neurological diseases that address frailty have the potential to provide insight into these complex disorders.

Aging is associated with an increased risk of cardiovascular disease and vascular dysfunction. Reduced nitric oxide bioavailability is considered one of the key mechanisms underlying vascular dysfunction in large arteries of older adults. However, the relationship between cardiovascular disease risk factors, nitric oxide bioavailability, and skeletal muscle microvascular reactivity, an early hallmark in cardiovascular disease progression, is unclear in older individuals. Also uncertain is whether this relationship is influenced by sex. Therefore, this study assessed the association between cardiovascular disease risk factors, circulating markers of nitric oxide availability (plasma nitrate and nitrite), and skeletal muscle microvascular reactivity in older individuals. First, we confirmed in a cohort of young and older individuals that aging is associated with skeletal muscle microvascular dysfunction. Next, we observed that skeletal muscle microvascular reactivity (P = 0.653; η

In a rigorous 40-month study, we evaluated the geroprotective effects of metformin on adult male cynomolgus monkeys, addressing a gap in primate aging research. The study encompassed a comprehensive suite of physiological, imaging, histological, and molecular evaluations, substantiating metformin's influence on delaying age-related phenotypes at the organismal level. Specifically, we leveraged pan-tissue transcriptomics, DNA methylomics, plasma proteomics, and metabolomics to develop innovative monkey aging clocks and applied these to gauge metformin's effects on aging. The results highlighted a significant slowing of aging indicators, notably a roughly 6-year regression in brain aging. Metformin exerts a substantial neuroprotective effect, preserving brain structure and enhancing cognitive ability. The geroprotective effects on primate neurons were partially mediated by the activation of Nrf2, a transcription factor with anti-oxidative capabilities. Our research pioneers the systemic reduction of multi-dimensional biological age in primates through metformin, paving the way for advancing pharmaceutical strategies against human aging.

Caloric restriction (CR) is known for its anti-aging benefits, partly due to reduced oxidative stress and enhanced antioxidant defense. However, CR outcomes vary based on its intensity, timing, and duration. This study explored CR's effects on antioxidant activity in the heart and liver of male Wistar rats during aging. We investigated two CR paradigms: long-term CR (LTCR), started early in life, and short-term CR (STCR), initiated in middle or old age for 3 months. Contrary to previous findings of short-term CR deleterious effects of on the nervous system, our results revealed increased levels of key antioxidants after STCR. More specifically, we found an increase in GSH-Px and GSH under STCR that was particularly pronounced in the liver, while an increase in CAT and GR activities was observed in the heart of the STCR groups. Catalase was characterized as an enzyme particularly responsive to CR, as its activity was also increased in both the liver and heart after long-term caloric restriction. Our results highlight a significant tissue-specific response to CR and contribute to our understanding of the dynamic effects of CR, which in turn has implications for refining its therapeutic potential in combating age-related decline.

Dietary diversity is reported to be beneficial for cognitive function, while the effect may be offset by weight change status. We aimed to examine the association of dietary diversity and weight change with cognitive impairment among older adults.

An observational study suggested sodium-glucose cotransporter 2 (SGLT2) inhibitors might promote healthy aging. However, whether brain-related phenotypes mediate this association is still a question. We applied Mendelian randomization (MR) to investigate the effect of SGLT2 inhibition on chronological age, biological age, and cognition and explore the mediation effects of brain imaging-derived phenotypes (IDPs).

The accumulation and systemic propagation of senescent cells contributes to physiological aging and age-related pathology. However, which cell types are most susceptible to the aged milieu and could be responsible for the propagation of senescence has remained unclear. Here we found that physiologically aged bone marrow monocytes/macrophages (BMMs) propagate senescence to multiple tissues, through extracellular vesicles (EVs), and drive age-associated dysfunction in mice. We identified peroxisome proliferator-activated receptor α (PPARα) as a target of microRNAs within aged BMM-EVs that regulates downstream effects on senescence and age-related dysfunction. Demonstrating therapeutic potential, we report that treatment with the PPARα agonist fenofibrate effectively restores tissue homeostasis in aged mice. Suggesting conservation to humans, in a cohort study of 7,986 participants, we found that fenofibrate use is associated with a reduced risk of age-related chronic disease and higher life expectancy. Together, our findings establish that BMMs can propagate senescence to distant tissues and cause age-related dysfunction, and they provide supportive evidence for fenofibrate to extend healthy lifespan.

The decreased ability of mature oligodendrocytes to produce myelin negatively affects remyelination in demyelinating diseases and aging, but the underlying mechanisms are incompletely understood. In the present study, we identify a mature oligodendrocyte-enriched transcriptional coregulator diabetes- and obesity-related gene (DOR)/tumor protein p53-inducible nuclear protein 2 (TP53INP2), downregulated in demyelinated lesions of donors with multiple sclerosis and in aged oligodendrocyte-lineage cells. Dor ablation in mice of both sexes results in defective myelinogenesis and remyelination. Genomic occupancy in oligodendrocytes and transcriptome profiling of the optic nerves of wild-type and Dor conditional knockout mice reveal that DOR and SOX10 co-occupy enhancers of critical myelinogenesis-associated genes including Prr18, encoding an oligodendrocyte-enriched, proline-rich factor. We show that DOR targets regulatory elements of genes responsible for α-ketoglutarate biosynthesis in mature oligodendrocytes and is essential for α-ketoglutarate production and lipid biosynthesis. Supplementation with α-ketoglutarate restores oligodendrocyte-maturation defects in Dor-deficient adult mice and improves remyelination after lysolecithin-induced demyelination and cognitive function in 17-month-old wild-type mice. Our data suggest that activation of α-ketoglutarate metabolism in mature oligodendrocytes can promote myelin production during demyelination and aging.

Mosaic loss of the Y chromosome (mLOY) is a common somatic mutation in the blood of elderly men and several studies have found mLOY in blood cells to be associated with an increased risk of various diseases and mortality. However, most of these studies have focused on middle-aged and older adults, meaning that mLOY in extremely old individuals like centenarians is understudied. To explore mLOY across a wider age range compared to earlier studies and to specifically focus on centenarians, mLOY was estimated in 917 Danish men aged 56-100 years. We found that the percentage of men with LOY increased with age until age 85, after which it plateaued at around 40 %. Consistently, a longitudinal comparison of mLOY revealed that mLOY predominantly increased with age, although inter-individual variation was seen. Using a twin sub-sample, the broad-sense heritability of mLOY was estimated at 72 %, indicating a substantial genetic influence. Supporting previous findings, mLOY was found to associate with increased mortality across all study participants and in men younger than 80 years. In centenarians, however, a higher level of mLOY associated with better survival, most likely due to selection, although confirmation of our findings in larger studies is needed.

Aging is associated with a decline in oral immune function, marked by reduced levels of antimicrobial peptides such as defensins. Capsaicin, a bioactive component found in chili peppers, has been theorized to modulate immune responses through specific receptor pathways. This study examined the effects of aging on oral defensin levels and the potential mitigating role of capsaicin, mediated by the immune response in oral tissues. We conducted a comparative analysis between young and aged mice, with or without capsaicin supplementation, for 3 months. The effect of capsaicin was also studied in vitro in senescence-induced human oral keratinocytes. We found that aging did not reduce defensin levels uniformly but did so in some instances. Capsaicin treatment increased defensin levels in these cases, potentially through transient receptor potential cation channel subfamily V member 1 (TRPV1)-mediated pathways in the oral cavity. Capsaicin supplementation may counteract age-related declines in oral defensin levels, enabling the maintenance of oral immune function during aging.

"Blue Zones" (BZs) are regions with exceptionally high numbers of longevous inhabitants. Several factors have been suggested to promote longevity in BZs, but the evidence generally does not meet scientific quality criteria. We aimed to characterize a municipality as a "relative BZ," satisfying 3 criteria: compared to other municipalities, more exceptionally longevous inhabitants, a higher life expectancy, and a more stable population.

Telomere length is a biomarker of molecular aging that may be impacted by air pollution exposure starting in utero. We aimed to examine the association between prenatal and early life exposure to fine particulate matter (PM

The present study used a cross-lagged panel design with longitudinal data to test if there is a reciprocal relationship between cognitive control beliefs and cognition (e.g., executive functioning and episodic memory) over 10 years, whether frequency of engaging in stimulating cognitive activities mediated this relationship, and if these relationships varied by age.

Comparing transcriptome profiling between younger and older samples reveals genes related to aging and provides insight into the biological functions affected by aging. Recent research has identified sex, tissue, and cell type-specific age-related changes in gene expression. This study reports the overall picture of the opposite aging effect, in which aging increases gene expression in one cell subset and decreases it in another cell subset. Using the Tabula Muris Senis dataset, a large public single-cell RNA sequencing dataset from mice, we compared the effects of aging in different cell subsets. As a result, the opposite aging effect was observed widely in the genes, particularly enriched in genes related to ribosomal function and translation. The opposite aging effect was observed in the known aging-related genes. Furthermore, the opposite aging effect was observed in the transcriptome diversity quantified by the number of expressed genes and the Shannon entropy. This study highlights the importance of considering the cell subset when intervening with aging-related genes.

In skin aging, it has been hypothesized that aging fibroblasts accumulate within the epidermal basal layer, dermis, and subcutaneous fat, causing abnormal tissue remodeling and extracellular matrix dysfunction, thereby inducing an aging-related secretory phenotype (SASP). A new treatment for skin aging involves the specific elimination of senescent skin cells, especially fibroblasts within the dermis and keratinocytes in the basal layer. This requires the identification of specific protein markers of senescent cells, such as ribonucleoside-diphosphate reductase subunit M2 B (RRM2B), which is upregulated in various malignancies in response to DNA stress damage. However, the behavior and role of RRM2B in skin aging remain unclear. Therefore, we examined whether RRM2B functions as a senescence marker using a human dermal fibroblast model of aging. In a model of cellular senescence induced by replicative aging and exposure to ionizing radiation or UVB, RRM2B was upregulated at the gene and protein levels. This was correlated with decreased uptake of the senescence-associated β-galactosidase activity and proliferation marker bromodeoxyuridine. RRM2B upregulation was concurrent with the increased expression of SASP factor genes. Furthermore, using fluorescence flow cytometry, RRM2B-positive cells were recovered more frequently in the aging cell population. In aging human skin, RRM2B was also found to be more abundant in the dermis and epidermal basal layer than other proteins. Therefore, RRM2B may serve as a clinical marker to identify senescent skin cells.

Dysfunction of the ribosome manifests during cellular senescence and contributes to tissue aging, functional decline, and development of aging-related disorders in ways that have remained enigmatic. Here, we conducted a comprehensive CRISPR-based loss-of-function (LOF) screen of ribosome-associated genes (RAGs) in human mesenchymal progenitor cells (hMPCs). Through this approach, we identified ribosomal protein L22 (RPL22) as the foremost RAG whose deficiency mitigates the effects of cellular senescence. Consequently, absence of RPL22 delays hMPCs from becoming senescent, while an excess of RPL22 accelerates the senescence process. Mechanistically, we found in senescent hMPCs, RPL22 accumulates within the nucleolus. This accumulation triggers a cascade of events, including heterochromatin decompaction with concomitant degradation of key heterochromatin proteins, specifically heterochromatin protein 1γ (HP1γ) and heterochromatin protein KRAB-associated protein 1 (KAP1). Subsequently, RPL22-dependent breakdown of heterochromatin stimulates the transcription of ribosomal RNAs (rRNAs), triggering cellular senescence. In summary, our findings unveil a novel role for nucleolar RPL22 as a destabilizer of heterochromatin and a driver of cellular senescence, shedding new light on the intricate mechanisms underlying the aging process.

After prolonged space operations, astronauts showed maladaptive atrophy within mostly left-ventricular myocardium, resulting in cardiac dysfunction. However, the mechanism of cardiac dysfunction under microgravity conditions is unclear, and the relevant prevention and treatment measures also need to be explored. Through simulating the microgravity environment with a tail suspension (TS) model, we found that long-term exposure to microgravity promotes aging of mouse hearts, which is closely related to cardiac dysfunction. The intravenous administration of adipose-derived mesenchymal stem cells (ADSCs) emerged preventive and therapeutic effect against myocardial senescence and the decline in cardiac function. Plasma metabolomics analysis suggests the loss of NAD+ in TS mice and motivated myocardial NAD + metabolism and utilization in ADSCs-treated mice, likely accounting for ADSCs' function. Oral administration of nicotinamide mononucleotide (NMN, a NAD + precursor) showed similar therapeutic effect to ADSCs treatment. Collectively, these data implicate the effect of ADSCs in microgravity-induced cardiac dysfunction and provide new therapeutic ideas for aging-related maladaptive cardiac remodeling.

Cancer cachexia is the prototypical example of comorbidity, occurring in most of cancer patients. It is a direct consequence of tumor growth and of the associated inflammatory/immune response. Cachexia can be exacerbated by anti-cancer therapies, frequently resulting in dose limitation and/or treatment delay or discontinuation. The pathogenesis of cancer cachexia is still unclear and includes nutritional, metabolic, hormonal and immunological components. Tumor ability to shape the immune response to its own advantage is now well accepted, while the possibility that such an altered immune response could play a role in the onset of cachexia is still an undefined issue. Indeed, most of the immune-related research on cachexia mainly focused on pro-inflammatory mediators, almost totally disregarding the interactions among immune cells and the homeostasis of peripheral tissues. The present review provides an overview of the immune system dysregulations occurring in cancer cachexia, focusing on the possibility that immunomodulating strategies, mainly developed to stimulate the anti-cancer immune response, could be useful to counteract cachexia as well. Cancer and cachexia are frequent comorbidities of aging. Along this line, cancer- and aging-associated muscle wasting likely coexist in the same patients. Since both conditions share some of the underlying mechanisms, the potential effectiveness of immunomodulation on sarcopenia of aging is discussed.

Stem cell-based therapy has emerged as an attractive approach for regenerative medicine. Poor survival and maintenance of the cells used in regenerative medicine are considered as serious barriers to enhance the efficacy of the cell therapy. Using some antioxidants has been reported to prevent the aging of stem cells, and finding effective factors to reduce the senescence of these cells has impressive potential in cell therapy. The PI3K pathway adversely regulates the transcription factors known as FOXO, which are thought to have an inhibitory influence on cell proliferation. By downregulating FOXO and other targets, PI3K signaling controls the growth of cells. For this reason, the aim of the present study is to investigate the effect of L-carnitine (LC) as antioxidant on the cell proliferation and the protein expression of PI3K and FOXO.

Sarcopenia, characterized by the progressive loss of skeletal muscle mass and function, significantly impacts health outcomes in older adults. This review explores the evolving landscape of sarcopenia research, with a particular focus on its unique characteristics in Asian populations and emerging pharmaceutical interventions. Recent studies have revealed distinct patterns of muscle mass decline in Asian adults, particularly in women, challenging the universal application of global sarcopenia diagnostic criteria. The Asian Working Group for Sarcopenia has proposed region-specific diagnostic criteria, acknowledging these ethnic variations. Prevalence estimates of sarcopenia vary widely, ranging from 10% to 40% in community-dwelling older adults. For specific chronic conditions, the prevalence of sarcopenia is notably higher, reaching 35% for cardiovascular diseases and 24.5% for chronic kidney disease. Sarcopenia is strongly associated with various chronic conditions, increasing the risk of falls by 1.5 to 3 times and significantly increasing mortality risk by 29% to 51%. Current management strategies primarily involve resistance exercise and nutritional interventions, with a recommended daily protein intake of at least 1.2 g/kg to maintain muscle health. Pharmaceutical development has gained significant momentum, with over 20 compounds in various stages of clinical trials. These include myostatin inhibitors, selective androgen receptor modulators, ghrelin receptor agonists, mesenchymal stem cell therapy, and follistatin gene therapy. However, the unique dietary patterns, cultural contexts, and potentially distinct drug responses in Asian populations necessitate tailored interventions and Asia-specific clinical trials. Future directions include refining Asian-specific diagnostic criteria, conducting large-scale epidemiological studies across multiple Asian countries, developing culturally appropriate interventions, integrating sarcopenia management into chronic disease care, and advancing pharmaceutical research with a focus on Asian populations. In conclusion, sarcopenia emerges as a critical nexus in the aging process, intricately linked with multiple organ systems and chronic conditions, underscoring the imperative for its recognition as a cornerstone in person-centered care and the holistic management of age-related health challenges.

This article presents evidence supporting the hypothesis that starting aerobic exercise in early adulthood and continuing it throughout life leads to significant neurocognitive benefits compared with starting exercise later in life. Regular aerobic exercise at moderate-to-vigorous intensity during midlife is associated with significant improvement in cardiorespiratory fitness, which may create a favorable brain microenvironment promoting neuroplasticity through enhanced vascular function.

The process of aging is a notable risk factor for numerous age-related illnesses. Hence, a reliable technique for evaluating biological age or the pace of aging is crucial for understanding the aging process and its influence on the progression of disease. Epigenetic alterations are recognized as a prominent biomarker of aging, and epigenetic clocks formulated on this basis have been shown to provide precise estimations of chronological age. Extensive research has validated the effectiveness of epigenetic clocks in determining aging rates, identifying risk factors for aging, evaluating the impact of anti-aging interventions, and predicting the emergence of age-related diseases. This review provides a detailed overview of the theoretical principles underlying the development of epigenetic clocks and their utility in aging research. Furthermore, it explores the existing obstacles and possibilities linked to epigenetic clocks and proposes potential avenues for future studies in this field.

Roles of the sirtuins in aging and longevity appear related to their evolutionarily conserved functions as retroviral-restriction factors. Retrotransposons also promote the aging process, which can be reversed by the inhibition of their activity. SIRT6 can functionally limit the mutation activity of LINE-1 (L1), a retrotransposon causing cancerogenesis-linked mutations accumulating during aging. Here, an overview of the molecular mechanisms of the controlling effects was created by the pathway enrichment and gene function prediction analysis of a protein interaction network of SIRT6 and L1 retrotransposon proteins L1 ORF1p, and L1 ORF2p. The L1-SIRT6 interaction network is enriched in pathways and nodes associated with RNA quality control, DNA damage response, tumor-related and retrotransposon activity-suppressing functions. The analysis also highlighted sumoylation, which controls protein-protein interactions, subcellular localization, and other post-translational modifications; DNA IR Damage and Cellular Response via ATR, and Hallmark Myc Targets V1, which scores are a measure of tumor aggressiveness. The protein node prioritization analysis emphasized the functions of tumor suppressors p53, PARP1, BRCA1, and BRCA2 having L1 retrotransposon limiting activity; tumor promoters EIF4A3, HNRNPA1, HNRNPH1, DDX5; and antiviral innate immunity regulators DDX39A and DDX23. The outline of the regulatory mechanisms involved in L1 retrotransposition with a focus on the prioritized nodes is here demonstrated in detail. Furthermore, a model establishing functional links between HIV infection, L1 retrotransposition, SIRT6, and cancer development is also presented. Finally, L1-SIRT6 subnetwork SIRT6-PARP1-BRCA1/BRCA2-TRIM28-PIN1-p53 was constructed, where all nodes possess L1 retrotransposon activity-limiting activity and together represent candidates for multitarget control.

Old trees are remarkable for their ability to endure for centuries or even millennia, acting as recordkeepers of historical climate and custodians of genetic diversity. The secret to their longevity has long been a subject of fascination. Despite the challenges associated with studying old trees, such as massive size, slow growth rate, long lifespan and often remote habitat, accumulating studies have investigated the mechanisms underlying tree aging and longevity over the past decade. The recent publication of high-quality genomes of long-lived tree species, coupled with research on stem cell function and secondary metabolites in longevity, has brought us closer to unlocking the secrets of arboreal longevity. This review provides an overview of the global distribution of old trees and examines the environmental and anthropogenic factors that shape their presence. We summarize the contributions of physiological characteristics, stem cell activity, and immune system responses to their extraordinary longevity. We also explore the genetic and epigenetic 'longevity code', which consists of resistance and defense genes, DNA repair genes and patterns of DNA methylation modification. Further, we highlight key areas for future research that could enhance our understanding of the mechanisms underlying tree longevity.

With the acceleration of population aging, disability in older adults is a growing public health problem; however, little is known about the role of specific leisure-time activities in affecting disability. This study prospectively examined the association of leisure-time activities with disability among the Chinese oldest old. A total of 14 039 adults aged 80 years or older (median age of 89.8 years) were enrolled from the Chinese Longitudinal Healthy Longevity Survey from 1998 to 2014. Disability was defined as the presence of concurrent impairment in activities of daily living and physical performance. Cox proportional hazards models were used to estimate the associations between leisure-time activities and disability. During a mean of 4.2 years (2.7 years) of follow-up, 4487 participants developed disability. Compared with participants who never engaged in leisure-time activities, participants who engaged in almost daily activities, including gardening, keeping domestic animals or pets, playing cards or mahjong, reading books or newspapers, and watching TV or listening to the radio had a lower risk of disability, with HRs of 0.78 (0.69-0.88), 0.64 (0.58-0.70), 0.74 (0.63-0.86), 0.74 (0.65-0.84), and 0.84 (0.77-0.90), respectively. Moreover, the risk of disability gradually decreased with participation in an increasing number of those leisure-time activities (P for trend <0.001). Frequent engagement in leisure-time activities was associated with a lower risk of disability among the Chinese oldest old. This study highlights the importance of incorporating a broad range of leisure-time activities into the daily lives of older adults.

Biological age (BA), reflecting aging-related health decline beyond chronological age, varies among individuals. While previous research explored associations of maternal pregnancy-related body size with offspring health outcomes, its implications for BA in young adults remain unclear. Utilizing longitudinal data of 1148 mother-offspring pairs from the Jerusalem Perinatal Study, we analyzed associations of maternal prepregnancy BMI and gestational weight gain (GWG) with offspring using the Klemera-Doubal method (KDM)-based BA at age 32 and potential familial life-course underlying mechanisms. Maternal pregnancy-related body size, adjusted for sociodemographic/lifestyle factors was associated with offspring BA (βmaternal prepregnancy BMI = 0.183; 95% CI, 0.098-0.267; βGWG = 0.093; 95% CI, 0.021-0.165). Association of GWG with BA was largely direct (90%; 95% CI, 44%-100%), while association with maternal prepregnancy BMI was partially mediated through adolescent BMI (36%; 95% CI, 18%-75%), with both associations eliminated after adjustment for offspring adult BMI. Associations persisted after adjusting for offspring polygenic risk score for BMI (βmaternal prepregnancy BMI = 0.128; 95% CI, 0.023-0.234; βGWG = 0.102; 95% CI, 0.006-0.198), and somewhat altered after adjustment for maternal cardiometabolic conditions (βmaternal prepregnancy BMI = 0.144; 95% CI, 0.059-0.230). Impact on GWG associations was negligible. Thus, perinatal obesogenic environment contributes to offspring BA beyond sociodemographic factors and maternal cardiometabolic history, yet intergenerational transmission of obesity seems to underlie these associations. Nonetheless, the period between adolescence and young adulthood could be targeted for weight-reducing interventions, ultimately promoting healthy aging.

We rigorously assessed a comprehensive association testing framework for heteroplasmy, employing both simulated and real-world data. This framework employed a variant allele fraction (VAF) threshold and harnessed multiple gene-based tests for robust identification and association testing of heteroplasmy. Our simulation studies demonstrated that gene-based tests maintained an appropriate type I error rate at α = 0.001. Notably, when 5 % or more heteroplasmic variants within a target region were linked to an outcome, burden-extension tests (including the adaptive burden test, variable threshold burden test, and z-score weighting burden test) outperformed the sequence kernel association test (SKAT) and the original burden test. Applying this framework, we conducted association analyses on whole-blood derived heteroplasmy in 17,507 individuals of African and European ancestries (31 % of African Ancestry, mean age of 62, with 58 % women) with whole genome sequencing data. We performed both cohort- and ancestry-specific association analyses, followed by meta-analysis on both pooled samples and within each ancestry group. Our results suggest that mtDNA-encoded genes/regions are likely to exhibit varying rates in somatic aging, with the notably strong associations observed between heteroplasmy in the RNR1 and RNR2 genes (p < 0.001) and advance aging by the Original Burden test. In contrast, SKAT identified significant associations (p < 0.001) between diabetes and the aggregated effects of heteroplasmy in several protein-coding genes. Further research is warranted to validate these findings. In summary, our proposed statistical framework represents a valuable tool for facilitating association testing of heteroplasmy with disease traits in large human populations.

Ageing is a complex multifactorial process, impacting all organs and tissues, with DNA damage accumulation serving as a common underlying cause. To decelerate ageing, various strategies have been applied to model organisms and evaluated for health and lifespan benefits. Dietary restriction (DR, also known as caloric restriction) is a well-established long-term intervention recognized for its universal anti-ageing effects. DR temporarily suppresses growth, and when applied to progeroid DNA repair-deficient mice doubles lifespan with systemic health benefits. Counterintuitively, attenuation of myostatin/activin signalling by soluble activin receptor (sActRIIB), boosts the growth of muscle and, in these animals, prevents muscle wasting, improves kidney functioning, and compresses morbidity.

As a widespread global issue, protein deficiency hinders development and optimal growth in offspring. Maternal low-protein diet influences the development of age-related diseases, including sarcopenia, by altering the epigenome and organ structure through potential increase in oxidative stress. However, the long-term effects of lactational protein restriction or postnatal lifelong protein restriction on the neuromuscular system have yet to be elucidated. Our results demonstrated that feeding a normal protein diet after lactational protein restriction did not have significant impacts on the neuromuscular system in later life. In contrast, a lifelong low-protein diet induced a denervation phenotype and led to demyelination in the sciatic nerve, along with an increase in the number of centralised nuclei and in the gene expression of atrogenes at 18 months of age, indicating an induced skeletal muscle atrophy. These changes were accompanied by an increase in proteasome activity in skeletal muscle, with no significant alterations in oxidative stress or mitochondrial dynamics markers in skeletal muscle later in life. Thus, lifelong protein restriction may induce skeletal muscle atrophy through changes in peripheral nerves and neuromuscular junctions, potentially contributing to the early onset or exaggeration of sarcopenia.

Aging-induced decline in ciliary muscle function is an important factor in visual accommodative deficits in elderly adults. With this study, we provide an innovative investigation of the interaction between ciliary muscle aging and oxidative stress.

The importance of the gut microbiome for human health and well-being is generally accepted, and elucidating the signaling pathways between the gut microbiome and the host offers novel mechanistic insight into the (patho)physiology and multifaceted aspects of healthy aging and human brain functions.