Longevity Papers

Extracellular matrix (ECM), once regarded as a passive structural scaffold, is now recognized as a key hallmark of aging. In the context of female reproductive aging, ECM remodeling acts as a pivotal driver of functional deterioration. This review outlines how age-associated ECM alterations, including collagen cross-linking, elastin degradation, and perturbed biomechanics, orchestrate ovarian aging through the mechanical activation of Hippo signaling, compromise endometrial receptivity via dysregulated matrix metalloproteinase activity, and impair embryo invasion by altering ligand presentation. We also discuss emerging ECM-targeted strategies, such as decellularized scaffolds, engineered hydrogels, and 3D-bioprinted matrices, which have demonstrated potential for rejuvenating reproductive function in preclinical models. Furthermore, matrisome-based biomarkers provide novel prognostic insights into reproductive outcomes. Collectively, these advances identify the ECM as a promising target for innovative, non-hormonal interventions aimed at extending female reproductive longevity.

Frailty, defined by progressive loss of physiological resilience, neuromuscular function, and cognitive capacity, is a central manifestation of biological aging yet remains difficult to quantify in scalable experimental systems. Here, we introduce a Composite Frailty Index (CFI) in the house cricket (Acheta domesticus) that integrates automated measures of locomotion, exploratory behavior, and freezing into a unified, quantitative framework of functional decline. Ten behavioral parameters derived from automated open-field tracking, including locomotor performance, exploratory behavior, and freezing were integrated into the CFI. Locomotor states were classified using k-means clustering (k = 2) of velocity distributions, and all features were normalized to age- or treatment-matched reference populations, discretized into quintiles, and summed to generate a 0-40 frailty score. Aging cohorts (young adult: 4-6 weeks; geriatric: 10-12 weeks, N = 103) and pharmacological cohorts treated at mid-life (8-10 weeks) with rapamycin (14 ppm), acarbose (1000 ppm), or phenylbutyrate (1000 ppm) were evaluated (N = 122). Across chronological aging cohorts, CFI increased from young adults to geriatrics in both females (d = 1.14 [95% CI: 0.53, 1.76], P = 0.0003) and males (d = -1.17 [95% CI: -1.75 to -0.59], P < 0.0001). Using pharmacological intervention cohorts, mid-life rapamycin treatment reduced late-life frailty relative to controls in both females (d = -1.31 [95% CI: -2.09, -0.53], P = 0.0017) and males (d = -1.33 [95% CI: -2.09, -0.58], P = 0.0004), whereas acarbose and phenylbutyrate produced inconclusive effects (d's = -0.54 to -0.03; P's > 0.05). Together, these findings establish the cricket CFI as a scalable, high-throughput platform for quantifying multidimensional functional aging and prioritizing candidate geroprotective interventions based on clinically relevant endpoints beyond lifespan.

Age-related macular degeneration (AMD) is a leading cause of irreversible blindness in the elderly and has a multifactorial etiology involving advanced age, genetic susceptibility, and environmental risk factors. Accumulating evidence suggests that mitochondrial dysfunction is a central pathogenic mechanism in AMD, particularly in the retinal pigment epithelium (RPE). The RPE is critical for retinal homeostasis, and its high metabolic activity renders it vulnerable to age-related mitochondrial dysfunction. In AMD, the core processes of mitochondrial dynamics-fission, fusion, biogenesis, and mitophagy-are profoundly dysregulated, leading to a fragmented and dysfunctional mitochondrial network. This failure of quality control results in bioenergetic deficits, excessive oxidative stress, and the release of damage-associated molecular patterns that fuel chronic inflammation and complement-mediated damage. Experimental models and human tissue studies have strengthened the link between mitochondrial dysfunction and AMD pathology, revealing structural abnormalities, mitochondrial DNA (mtDNA) damage, and altered metabolic signatures. Therapeutic strategies targeting mitochondrial pathways, including mitochondria-targeted antioxidants, dynamic modulators, and enhancers of biogenesis and mitophagy, such as agents that restore defective mitophagosome formation, represent promising avenues for intervention. As the field advances, the integration of biomarker development and personalized approaches holds the potential to transform the clinical landscape of AMD by addressing the root causes of cellular dysfunction.

Background Prenatal exposure to pesticides and psychosocial factors often co-occurs, particularly in low- and middle-income settings, yet their joint effects on epigenetic age acceleration (EAA) in early life remain unknown. We investigated the joint associations of prenatal pesticides metabolites and psychosocial factors on EAA in the first five years of life in the South African Drakenstein Child Health Study. Methods In 643 mothers, we measured 11 urinary pesticide metabolites and seven psychosocial factors during the second trimester of pregnancy. Child DNA methylation was measured in whole blood at ages 1, 3, and 5 years. EAA was estimated using the Horvath, Skin & Blood Horvath (skinHorvath), and Wu epigenetic clocks. Longitudinal associations were estimated using generalized estimating equations, adjusted for confounders. Joint mixture associations were evaluated using weighted quantile sum regression (WQS) and quantile g-computation (QGCOMP). Results The joint prenatal exposure mixture was positively associated with Wu ({beta} per one quintile increase in the mixture [95% CI]: 0.41 years [0.15, 0.80]), skinHorvath (0.11 years [0.06, 0.16]), and Horvath EAA (0.31 years [0.20, 0.46]) over time using WQS. Psychosocial factors, particularly food insecurity, physical interpersonal violence, and stress biomarkers, contributed most to the total mixture effect for all clocks. Pyrethroid metabolites PBA and TDCCA were top pesticide contributors to Wu EAA. Pathway enrichment analyses of clock-specific CpGs revealed distinct biological architectures, with the Wu clock enriched for neurodevelopmental and immune pathways, and metabolic pathways for the Horvath clock. Discussion Joint prenatal exposure to pesticides and psychosocial factors was associated with increased EAA across early childhood, with psychosocial factors contributing the most to the total effect. These findings highlight the importance of assessing chemical and non-chemical stressors jointly and clock-specific biological interpretation in epigenetic aging research.

The muscle-tendon junction (MTJ) is a specialised interface between muscle and tendon and transmits muscle-generated force to the tendon. The MTJ is particularly vulnerable to injuries compared to muscle and tendon and becomes more injury prone with age. Despite its clinical importance, the mechanisms driving MTJ ageing and age-related functional deterioration remain poorly understood. In this study, young (3-month-old) and old (23-month-old) male mice were used to provide the first comprehensive three-dimensional characterisation of age-related structural and cellular changes at the mouse Achilles MTJ. This was achieved using the high-resolution imaging techniques, micro-computed tomography (µCT) and confocal microscopy. µCT analysis revealed a 27% reduction in muscle fibre diameter with age, accompanied by a trend toward increased MTJ surface area and a 19% reduction in pennation angle, which may indicate diminished force generation capacity. Confocal imaging showed a 49% reduction in endothelial cell volume (VWF-labelled) in the old mouse muscle-tendon unit, suggesting a loss of vascularity. In situ hybridisation demonstrated increased expression of senescence markers p16 and p21 in endothelial and MTJ-specific cells, with MTJ-specific cells showing the greatest accumulation of p16 and p21 (270% and 310% increases, respectively) with age, and immunofluorescence also showed increased expression of p21. These findings suggest that vascular and MTJ-specific cells are particularly susceptible to ageing and may collectively contribute to the age-related functional decline of the MTJ. Understanding these mechanisms may help to develop targeted therapeutic strategies to preserve or restore MTJ integrity and function in ageing populations.

Lead (Pb) is a pervasive environmental hazard that impairs cognitive function. However, the underlying mechanisms and non-pharmacological interventions need to be further investigated. Here, Pb-induced senescence in the prefrontal cortex was associated with cognitive impairment. We found that exercise and exercise serum ameliorated Pb-induced prefrontal cortex senescence and cognitive impairment in mice. Further analyses revealed that exercise-derived irisin alleviated cellular senescence by regulating the SIRT3 signaling pathway. Meanwhile, irisin also mediated the association between blood Pb levels and MoCA scores in humans. Together, these findings suggest that exercise alleviates Pb-induced cognitive impairment via the irisin-SIRT3 pathway and identify irisin as a potential therapeutic target.

Interventions to extend lifespan and healthspan are of major interest, but such interventions may affect male and female organisms differently. Whether this is due sex-specific differences in baseline lifespan, or differences in sexually dimorphic characteristics such as body size, adiposity, metabolism, or even gonadal hormone or chromosome status remains unknown. Here we discuss the literature on how males and females respond differently to various types of interventions known to extend lifespan and explore possible underlying mechanisms. Ultimately, understanding sex as a biological variable in the context of aging may reveal sex-specific strategies to improve healthspan and treat age-related disease.

Aging is a complex, multifactorial process, influencing disease risk and overall health. While chronological age (CA) is widely used in clinical practice, it fails to capture individual aging trajectories. Current approaches to estimate biological age (BA) often focus on single organs or predefined clinical biomarkers, limiting comprehensive assessment. We introduce a novel, purely imaging-driven deep learning framework for organ-specific BA estimation across seven organ systems. Our uncertainty-aware ResNet-based models autonomously learned aging-related features from imaging data in 70,000 UK Biobank participants, eliminating manual feature selection biases. Training on a healthy cohort, where CA approximates BA, allows learning normative aging patterns. When applied to a broader cohort, deviations from typical aging indicate older or younger BA. Our findings demonstrate the feasibility of BA estimation, even in organs with subtle aging features. While aging is largely heterogeneous across organs, we also identified correlations in aging patterns. We further showed that accelerated aging is prognostic of mortality and health outcomes, offering insights for personalized assessments.

An imbalance of DNA damage over DNA repair contributes to the genomic instability that drives aging and numerous age-related diseases. While numerous DNA repair mechanisms have been elucidated over decades of study, little is known about the contribution of metabolism to genomic stability. We report that adipose triglyceride lipase (ATGL), a primary lipolytic enzyme, promotes DNA repair. We show that lipid droplets (LDs) accumulate in response to DNA damage and that inhibition of LD biogenesis before genotoxic stress increases the persistence of DNA damage. Overexpression of ATGL (increasing lipolysis) enhances DNA repair in response to etoposide and ionizing radiation, thus reducing DNA damage burden. Mechanistically, ATGL promotes bulk acetylation of chromatin-bound proteins and blockade of the histone acetyltransferase p300 negates these effects. Further, ATGL-induced DNA repair attenuates the long-term consequences of DNA damage, and reducing senescence and enhancing viability. Overall, these studies reveal a novel role for LDs and LD proteins in DNA damage and repair, thus unveiling a mechanism through which lipid metabolism contributes to genomic stability.

High temperature requirement protein A1 (HTRA1) is a trypsin-like serine protease increasingly recognized as a central regulator of brain homeostasis. HTRA1 is broadly expressed in the brain, where it regulates proteostasis, extracellular matrix (ECM) remodeling, and important signaling pathways such as TGF-β, Wnt, and Notch. These functions are essential for maintaining blood-brain barrier integrity, supporting tissue repair, and restraining inflammation. HTRA1 is a double-edged sword, as both insufficient and excessive activity can lead to neurodegenerative and vascular pathology. Reduced HTRA1 levels are linked to ECM accumulation and vascular fibrosis, while elevated activity contributes to tissue breakdown, inflammation, and impaired repair. This dual role is implicated in a range of disorders, including cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy, small vessel disease, age-related macular degeneration, Alzheimer's disease, Parkinson's disease, and multiple sclerosis. We review recent insights into HTRA1's interactions with ApoE and tau, its roles in lipid and cytoskeletal regulation, and its modulation by inhibitors such as Macrophage Migration Inhibitory Factor. Finally, we explore its biomarker potential and therapeutic targeting strategies. Understanding the mechanisms behind HTRA1's shift from protective to pathological is crucial for developing targeted therapies that preserve its beneficial roles.

Chronic oxidative stress is a major contributor to neuronal aging. Due to the lack of homologous recombination (HR) DNA damage repair, high oxygen consumption in neurons causes DNA damage accumulation with age, resulting in a decline in neuronal function, senescence-like phenotypes and onset of neurodegenerative diseases. Here, we identify increased PTBP1 as a stress-inducible negative regulator of neuronal gene expression and senescence-protectant genes. Oxidative stress robustly increases PTBP1 expression in ShSY-5Y differentiated neurons and primary mouse cortical neurons, coinciding with the loss of neuronal genes, including neuronal PTBP2, and activation of stress-responsive genes. Knockdown of PTBP1 in fibroblasts reduces the expression of key senescence genes. Transcriptomic analyses revealed that PTBP1 overexpression results in coordinated shift in gene expression characterized by repression of neuronal commitment genes and activation of stress and senescence genes. Mechanistically, PTBP1 induction is regulated by stress induced CTCF binding at the PTBP1 promoter. Together, our findings suggest that alteration in levels of PTBP1 acts as a molecular switch between neuronal function and survival, providing insight into transcriptional adaptations associated with aging.

Mitochondrial dysfunction and metabolic imbalance are major contributors to the progression of age-related disorders, including cardiovascular diseases. Current therapeutic strategies increasingly focus on preserving mitochondrial integrity and promoting healthspan to reduce cardiometabolic burden. The standardized, chemically well-defined adaptogenic combination ADAPT-232 has a long history as a stress-protective remedy, enhancing cognitive and physical resilience. However, its effects on healthspan, particularly mitochondrial function, and the underlying molecular mechanisms remain insufficiently understood.

The identification of prefrailty, a reversible state of vulnerability in older adults, remains a clinical challenge. Arterial stiffness-a hallmark of vascular aging-has been implicated in frailty, suggesting shared pathophysiology. This link between prefrailty and early vascular dysfunction provides a rationale for exploring arterial pulse signals. This study investigated whether spectral pulse analysis could yield objective biomarkers for prefrailty.

Aging is a complex biological process, and biological aging can be quantified by epigenetic clocks. Depression and anxiety are highly prevalent among older adults and are established risk factors for adverse health outcomes. However, their relationships with epigenetic age acceleration (EAA) remain unclear, particularly in Asian populations. Using data from the Diet and Healthy Aging cohort, the present study examined the associations between depressive and anxiety symptoms and EAA within community-dwelling older adults (aged ≥ 60 years, n = 672). Depressive symptoms were assessed using the Geriatric Depression Scale (GDS), and anxiety symptoms were measured using the Geriatric Anxiety Inventory (GAI). Linear mixed-effects models were fitted to all available observations to account for within-person clustering, with additional within-person change analysis conducted among participants with repeated DNA methylation profiles (n = 116). These were followed by rigorous sensitivity analyses to inspect robustness. We found that depressive symptoms, but not anxiety, were robustly associated with higher EAA, primarily indexed by PCPhenoEAA. In fully adjusted models, each standard deviation (SD) increase in depressive symptoms corresponded to a 0.087 SD increase in PCPhenoEAA (β = 0.087, 95% CI [0.023, 0.151], p = 0.008). Participants screening positive for depression (GDS ≥ 5) exhibited, on average, 0.244 SD higher PCPhenoEAA compared with those without depression (β = 0.244, 95% CI [0.027, 0.461], p = 0.030). Despite relatively stable EAA across the follow-up period, within-person change in depressive symptoms was associated with a concomitant increase in PCPhenoEAA. Our findings highlight depression as an important and potentially modifiable factor in delaying biological aging among older Asian adults, highlighting the need for timely screening and interventions to promote healthy aging.

The quest for an elixir of longevity has long inspired research into molecular mechanisms that govern aging. The present study investigated the effects of resveratrol (RV) and nanodiamonds (NDs) on sirtuin activity, oxidative stress, and DNA damage in two strains of Acheta domesticus: wild-type (H) and longevity-selected (D). Analyses of total SIRT and SIRT1, SIRT6 activities, antioxidant markers (CAT, SOD, LPO), and DNA damage indicators (pATM, γH2A.X, DSBs) revealed strain- and stage-dependent variations without a consistent pattern, suggesting long-term modulation of lifespan or sirtuin activity. RV and NDs induced only transient and adaptive effects, including a short-term increase in sirtuin activity exposed to NDs. The long-lived strain displayed stability in sirtuin response and survival, indicating that longevity-regulating mechanisms are genetically conserved and resistant to external modulation. These findings offer new insights into the limited and context-dependent influence of nanomaterials and bioactive compounds on aging-related molecular pathways.

Background: This study investigates whether proteomic aging clocks (PACs) are associated with cerebral small vessel disease (CSVD). Methods: We included participants from two US community-based cohorts: the Atherosclerosis Risk in Communities (ARIC) Study and the Multi-Ethnic Study of Atherosclerosis (MESA) Study. These analyses leveraged PACs that were developed in ARIC using proteomics measured by SomaScan in midlife (Visit 2; mean age 56 y; n=1,486) and late-life (Visit 5; mean age 76 y; n=1,496), trained on chronological age. Proteomic age acceleration (PAA) was calculated as residuals from regressing PACs on chronological age. 3T brain MRI data were collected in late-life. We examined associations of PAA with log-transformed white matter hyperintensity (WMH) volume using linear regression and with the presence of microbleeds, and subcortical, lacunar, and cortical infarcts using logistic regression. Associations of PACs with WMH volume and microbleeds were tested in MESA using proteins measured at Exam 1 (mean age 57 y; n=932) and Exam 5 (mean age 66 y; n=934). All associations were quantified per 5-year increase in PAA. All models were adjusted for demographics and cardiovascular risk factors. Results: In ARIC, higher midlife PAA was associated with greater WMH volume (percent difference: 25% [95% CI: 13%, 39%]) and higher odds of subcortical infarcts (OR: 1.24 [1.02, 1.51]). Late-life PAA was associated with all CSVD markers: WMH volume (percent difference: 20% [8%, 34%]), cerebral microbleeds (OR: 1.40 [1.15, 1.69]), subcortical (OR: 1.80 [1.47, 2.22]), lacunar (OR: 1.80 [1.46, 2.23]), and cortical infarcts (OR: 1.39 [1.07, 1.82]). In MESA, higher late-life PAA was associated with greater WMH volume (28% [3%, 58%]) but not with microbleeds. Conclusion: Accelerated proteomic aging is associated with a higher prevalence of MRI markers of CSVD, most predominantly in late-life. Understanding this relationship may help stratify those at higher risk of CSVD at an early stage.

Age-related alterations in myelin are a prominent feature of brain aging, yet how myelin-associated markers and oligodendrocyte lineage cell populations change across the primate lifespan remains incompletely characterized. Here, we provide a multimodal, cross-sectional analysis of myelin-related imaging and cellular markers in the prefrontal cortex (PFC) of age-matched both male and female rhesus macaques across postnatal development and aging using a multimodal approach combining magnetic resonance imaging (MRI), histological analysis, immunohistochemistry, and RNAscope in situ hybridization. We quantified regional gray and white matter volumes and myelin water fraction measures in prefrontal cortex (PFC) subregions BA9 and BA46 across four age groups: 5, 10, 15, and 30 years. Myelin water fraction and regional brain volumes exhibited age-dependent increases from childhood through adolescence, peaking at 15 years, followed by a decline in aged animals. Histological analyses revealed age-associated changes in myelin organization and the presence of myelin fragments within Iba1-positive microglia, along with dynamic alterations in the density of cells expressing oligodendrocyte lineage-associated markers, including Olig2 and oligodendrocyte precursor cell (OPC)-associated markers, in BA9 and BA46. OPC density displayed a non-linear, age-associated pattern across developmental and aging stages, coinciding temporally with changes in myelin-associated imaging measures. Our findings define an age-related framework of myelin alterations and oligodendrocyte lineage markers in the primate prefrontal cortex. This work establishes a reference dataset for oligodendrocyte lineage dynamics across the lifespan in a translationally relevant primate model, providing a foundation for future mechanistic and interventional studies of myelin maintenance during brain aging.

Sleep is thought to be important for the clearance of brain waste, but exactly how it does so is still debated. Here, we demonstrate that endocytosis in brain endothelial cells (BECs) of the blood-brain barrier (BBB) is enhanced during sleep, facilitating the removal of brain-derived waste, including amyloid-{beta}, into the circulation. Using proteomics, in vivo tracer imaging, and endothelial-specific genetic perturbations in mice, we demonstrate that sleep enhances endocytic vesicle formation and cargo transcytosis in brain endothelial cells (BECs). Conversely, blocking endocytosis through endothelial Dnm2 knockout suppresses BEC-mediated transport and elevates sleep need, revealing a causal feedback loop between sleep and vascular endocytosis. These findings identify BBB endocytosis as a key sleep-dependent clearance pathway with implications for neurodegenerative disease.

Aging in humans is a multidimensional complexity featured by systematic chronic inflammation and further accompanied by organ dysfunction, gut dysbiosis, immune senescence, and age-related diseases. Chronic inflammation in cells relates to secretory factors like the senescence-associated secretory phenotype which induces senescence in normal cells. Simultaneously, immune senescence is promoted by chronic inflammation, resulting in an impaired immune system unable to clear out senescent cells and inflammatory factors. Long term accumulation of elevated inflammatory factors in cells causes organ damage and leads to other age-related disorders. Eliminating inflammation could be a viable anti-aging strategy since it has been identified as an endogenous component in aging. Lately, products of natural origin have been gaining attention in combating age-related diseases and chronic inflammation. Various in vitro, in vivo, and clinical studies have well documented the role of Withania somnifera (WS) in alleviating inflammation and aging in cells by mediating several cellular signaling pathways. This review discusses the features and mechanisms of inflammation and aging (inflammaging) and the modulation of key associated pathways by WS, examining its role as a promising candidate for future strategies against inflammaging.

Adrenergic signalling is heavily implicated in human age-related disease and yet the potential for this neuroendocrine signalling pathway to modulate ageing has received little attention. Here, we use Drosophila melanogaster to test if adrenergic-like signalling can promote longevity by manipulating tyramine (TA) or octopamine (OA), the invertebrate equivalents of adrenergic hormones. Increased neuronal synthesis of TA boosts health and longevity in both sexes, whereas OA is marginally beneficial in males. Orally administered TA or OA extend female or male lifespan, respectively. Increased activation of the ß-adrenergic-like signalling in the gut, by manipulating a ß-adrenergic-like receptor, PKA or CrebB, is sufficient to delay female ageing. Transcriptional profiling reveals that CrebB links the ß-adrenergic pathway to longevity-promoting processes in the gut where its function is required for the beneficial effects of TA feeding in females. Here we show that localised activation of ß-adrenergic signalling has the potential to counter animal ageing.

Dietary protein intake mediates healthy aging in diverse species, with consumption of a low protein (LP) diet improving metabolic health in both humans and mice. In mice, the benefits of LP diets are sex-specific, with males exhibiting a stronger response to a LP diet than females. The reason for this sexually dimorphic response is unknown, but we hypothesized that sex hormones might be responsible for this difference. Here, we tested the role of sex hormones in the response to a LP diet by feeding intact and gonadectomized mice of both sexes either a Control (21% of calorie from protein) or LP (7% of calories from protein) diet, and assessing the effects on weight, body composition, glycemic control, and energy balance over the course of three months, followed by molecular and histological analysis of tissues from each group. We confirm that males show a stronger metabolic response to an LP diet than females, but that ovariectomy sensitizes female mice to the metabolic effects of an LP diet, making them respond more similarly to males; conversely, castration does not substantially impact the response of males to an LP diet. Molecularly, we find that gonadectomy and sex are important interactors that mediate the response of mechanistic target of rapamycin (mTOR) signaling, lipid homeostasis, and thermogenesis to an LP diet. Together, this data shows that the resistance of female mice to an LP diet is mediated by ovarian hormones and suggests the possibility that older female humans might receive enhanced benefits from LP diet feeding

Traumatic brain injury (TBI) disproportionately affects the elderly, yet the underlying mechanisms remain unclear. Here, we demonstrate that aged TBI brains predominantly harbor pro-inflammatory NLRP3+ microglia, in stark contrast to the neuroprotective Lysozyme+ microglia prevalent in young TBI brains. This age-dependent microglial dichotomy correlates with elevated mortality and impaired recovery in aged TBI mice. By leveraging an integrative multi-omics approach combined with metabolomics and epigenome analysis, we identify a previously unrecognized link between enhanced glycolysis and pro-inflammatory chromatin landscape in NLRP3+ microglia. Further investigation identifies ELF1 as a key transcription factor driving NLRP3+ microglia formation. Importantly, ablation of ELF1 reverses age-associated microglial dysfunction and improves TBI outcomes. Finally, we discover that Imeglimin, a clinically approved antihyperglycemic agent capable of crossing the blood brain barrier, inhibits ELF1 and reverses microglial phenotype, reducing acute mortality rate and leading to improved functional recovery of aged TBI mice. Our work elucidates the mechanistic basis of age-dependent TBI outcomes, reveals the crosstalk between metabolic rewiring and epigenetic regulation in microglial aging, and identifies ELF1 as a promising therapeutic target for improving TBI outcome.

Despite decades of biochemical study, a comprehensive map of the mammalian metabolome remains elusive. Mass spectrometry-based metabolomics detects thousands of small molecule-associated signals in mammalian tissues, but it is currently unclear how many of these reflect products of endogenous metabolism. Here, we leverage systematic in vivo isotope tracing to infer the biosynthetic origins of unidentified metabolites. We administered 26 different isotopically labelled nutrients to mice, measured circulating and tissue metabolite labelling by mass spectrometry, and developed a statistical framework to infer the number of carbon atoms incorporated from each of these precursors into more than 4,000 putative metabolites. We show this information can be harnessed for biosynthesis-aware structure elucidation using a multimodal AI model that co-embeds isotopic labelling patterns with chemical structures. This approach revealed several previously unrecognized families of mammalian metabolites, including cysteine-derived alkylthiazolidines, dithioacetal mercapturic acid derivatives, short-chain N-acyltaurines, acylglycyltaurines, and N-oxidized taurines. It further uncovered a family of mevalonate-derived isoprenoid metabolites that includes 2,3-dihydrofarnesoic acid, which is markedly depleted in both mouse and human aging. Age-related depletion of these isoprenoids is driven by impaired coenzyme A synthesis. Our work establishes the biosynthetic precursors for thousands of unidentified metabolites and reveals multiple previously unrecognized branches of mammalian metabolism.

Menopause is linked to cognitive decline and reduced brain metabolism, while estrogen (E2) therapy has been shown to mitigate these effects. Understanding the molecular mechanisms by which ovarian hormones and E2 influence neuroprotection is essential for developing strategies to maintain brain health in women. In this study, we examined how the loss of ovarian hormones, with or without E2 treatment, affects the brain proteome and mitochondrial energy production in aged female C57BL/6J mice (36-40 weeks). The mice underwent sham or ovariectomy (OVX) surgery and were fed a high-fat diet for 10 weeks; six weeks after surgery, OVX mice received either sesame oil or E2 treatment for four weeks. Proteomic analysis of brain homogenates revealed 4,992 proteins regulated by E2, with pathway analysis showing increased signaling proteins related to synaptogenesis. OVX reduced proteins involved in synaptic function, branched-chain amino acid and ketone metabolism, the TCA cycle, and oxidative phosphorylation (Complexes I, IV, and V), while E2 restored protein expression within these pathways. Despite alterations in OxPhos proteins, basal and state 3 mitochondrial respiration remained unchanged, although notable impairments in Complex IV enzymatic activity were apparent in OVX, which were partially reversed by E2 treatment. Overall, these results indicate that E2 supports brain health by maintaining proteins crucial for synaptic integrity and metabolism, while partially offsetting the functional decline in mitochondrial bioenergetics associated with menopause.

Mitochondrial DNA (mtDNA) encodes essential bioenergetic and metabolic machinery across eukaryotes, but it is susceptible to mutational damage. The high copy number, physical location and inheritance patterns of mtDNA mean that specialist approaches to mitigate such damage are needed. A common theme across many species is segregation or 'sorting out' of different mtDNA types-generating variance in mutant frequencies within and between generations, so that multiscale selection can act to remove deleterious mutations. Eukaryotes with different physiologies and ecologies use different strategies for this segregation. This article attempts to review and-with the aid of some bioinformatics and new modelling results-synthesize the ways that this segregation is achieved across different eukaryotic organisms. In parallel, the importance of segregation in human disease, longevity, agriculture and for biology on a rapidly changing planet is discussed. This article is part of the theme issue 'Evolutionary genetics of mitochondria: on diverse and common evolutionary constraints across eukarya'.

The link between longevity and mitochondrial function has been documented; therefore, we suspect that the evolution of mitochondrial DNA (mtDNA) is linked to the evolution of longevity. We selected 128 fish species with a wide range of longevity and inhabiting habitats with differing temperatures and examined their association with dN/dS ratios of mtDNA genes. Our findings (i) rule out environmental temperature as a primary driver of longevity, (ii) confirm the negative relationship between synonymous substitution rate and longevity for four of the mitochondrial protein coding genes, (iii) reveal a correlation of the fish body length at maturity with the dN/dS ratio for ATP6, ND1 and ND4, and (iv) highlight for the first time to our knowledge, a link between high conservation of the three cytochrome c oxidase (COX) genes and adaptation to temperatures in fishes. By extending conclusions drawn from mtDNA to individual genes, our study opens new avenues for exploring the ageing process. Moreover, the specific link between the evolution of COX genes and habitat temperature confirms the importance of complex IV in temperature adaptation. Our findings also suggest a link between dN/dS in complex I genes and longevity, highlighting the need to examine the functional association between their encoded peptides and lifespan. This article is part of the theme issue 'Evolutionary genetics of mitochondria: on diverse and common evolutionary constraints across eukarya'.

Cellular senescence drives aging and age-related dysfunction across multiple tissues, including the brain. Through a high-content, senescent cell-based phenotypic screen of a small panel of natural products, we identified tomatidine, an aglycone of tomatine found in tomatoes, as a previously unrecognized senotherapeutic agent. In senescent human brain microvascular endothelial cells and fibroblasts, tomatidine selectively suppressed SASP expression without affecting p16

Abdominal CT-based assessments of skeletal muscle may provide important prognostic information for all-cause mortality in aging adults. We aimed to evaluate whether AI-segmented muscle area and muscle density predict long-term survival in a large, retrospective adult population.

Skin aging reflects both intrinsic biological decline and extrinsic influences collectively known as the skin exposome, including ultraviolet (UV) radiation, air pollution, psychosocial stress, fatigue, sleep disruption, and suboptimal lifestyle behaviors. These factors contribute to cumulative molecular and structural damage, positioning the skin as both a visible marker of whole-body aging and a target for longevity strategies. This review examines the validity of an integrative "In and Out" approach, combining topical treatments, such as retinoids, peptides, antioxidants, and exosome-based formulations, with internal nutraceuticals including NAD

Hypoxia has been shown to extend lifespan in Caenorhabditis elegans through mechanisms involving HIF-1 and DAF-16, but the interplay with SKN-1/Nrf, a key regulator of oxidative stress responses, remains complex. Studies have shown that SKN-1 reduced lifespan when overexpressed in hypoxic environments. However, the mechanism behind SKN-1 regulation under hypoxia is largely unknown.

Foundational AI models have recently shown promise for predicting the impact of perturbations on cell states. However, current models typically consider only one cell state at a time, limiting their ability to learn how cellular responses unfold over time, particularly across long trajectories such as diseases of aging. Here, we develop a temporal AI model, MaxToki, trained on nearly 1 trillion gene tokens including cell state trajectories across the human lifespan to generate cell states across long timelapses of human aging. MaxToki generalized to unseen trajectories through in-context learning and predicted novel age-modulating targets that were experimentally verified to influence age-related gene programs and functional decline in vivo. MaxToki represents a promising strategy for temporal modeling to accelerate the discovery of interventions for programming therapeutic cellular trajectories.

Long noncoding RNAs (lncRNAs) regulate transcriptional and epigenetic programs during aging and senescence. However, no comprehensive studies have systematically integrated multilayered analyses to reveal their diverse regulatory roles. Moreover, lncRNAs with therapeutic potential in age-related diseases remain unexplored. Here we systematically perturbed 32 high-abundance aging- and senescence-associated lncRNAs (PtbAlncs) using a Perturb-seq-based CRISPR-dCas9-KRAB knockdown system coupled with single-nucleus multiomics profiling, enabling simultaneous transcriptomic and chromatin accessibility analysis. This analysis uncovered essential roles for previously uncharacterized lncRNAs in senescence regulation, validated computationally and experimentally. These lncRNAs modulate distinct single-cell RNA-sequencing modules through diverse yet overlapping epigenetic motifs in single-cell ATAC-sequencing modules. Among them, HOTAIRM1, a DNA repair-associated PtbAlnc, stabilizes DNA repair by cooperating with BANF1 and p53 at double-strand break loci within condensates. Its deficiency impairs DNA repair and triggers p53-mediated senescence. In aged mouse lungs, adeno-associated virus-mediated HOTAIRM1 overexpression reduced fibrosis, alleviated tissue damage, and promoted cellular proliferation, underscoring its therapeutic potential.

Global understanding of arterial aging remains limited despite its well-recognized medical and economic impact, hindering the development of effective mitigation strategies. The aorta, the major elastic artery, experiences a loss of homeostasis during aging that results from highly complex interactions. A promising approach to unravel the underlaying mechanisms is to investigate how aging affects the aortic transcriptome, leveraging the tremendous technological advances in RNA sequencing (RNA-seq). However, corresponding RNA-seq studies remain scarce and their interpretation hindered by a lack of standardization across experiments. In this study, we performed a meta-analysis of three publicly available bulk RNA-seq datasets from young and aged mouse aortas. After analyzing each dataset separately using a consistent bioinformatic pipeline, we combined differentially expressed genes across studies using Fisher's method. Subsequent gene set enrichment and protein-protein interaction analyses revealed coherent and functionally annotated changes in gene expression, notably associated with a broad immune response and possible infiltration of immune cells, extracellular matrix remodeling, osteochondrogenic signaling and mineralization, and glycolytic stress. We further identified a list of genes strongly altered by aging across studies. Our findings contribute to a better characterization of aortic aging at the molecular level and may support the development of targeted therapeutic strategies.

We examine whether delaying selection into secondary school streams can reduce socioeconomic inequality in cognitive aging. We link data on individuals aged 50+ from 14 European countries in the Survey of Health, Ageing and Retirement in Europe (SHARE) to a newly compiled database on reforms that postponed the age of first tracking. Exploiting within-country, within-cohort variation in tracking age, we find that later tracking significantly reduces socioeconomic status (SES)-related disparities in late-life cognition. A one-year increase in tracking age relative to the sample median reduces the SES gradient in word recall by around 8%. Furthermore, our analysis shows that delayed tracking narrows SES gaps in completed years of education and in completion of at least vocational upper-secondary school. It also improves access to white-collar, high-prestige and less physically demanding first jobs. These findings suggest that education policy should be incorporated into broader strategies aimed at reducing health disparities throughout the lifespan.

DNA damage arising from metabolic stress, oxidative injury, and impaired genome maintenance emerges as a common driver for chronic inflammatory and fibrotic diseases across multiple organs. While rapid and effective DNA damage repair is essential for the response to acute injury, sustained activation of these pathways promotes cellular senescence, sterile inflammation and fibroblast activation, ultimately driving fibrogenesis and pathological tissue remodelling. In recent years, DNA repair processes, particularly base excision repair in both the nucleus and mitochondria, receive increasing attention as modulators of inflammatory and fibrotic outcomes. Here, we review the molecular mechanisms by which unresolved nuclear and mitochondrial DNA lesions translate into chronic inflammation and fibrosis across skin, liver, lung and cardiovascular tissues. We discuss the roles of chromatin context, NAD

Mitochondrial degeneration and dysfunctions are increasingly linked with neurodegenerative diseases, with the greatest risk factor being increased age. Mitochondrial dysfunction is also implicated in sarcopenia, the age-associated weakness and atrophy of striated muscle. Untangling the pathophysiological effects of age-related mitochondrial degeneration and dysfunction is of huge interest in gerontology. In elderly humans and Fischer 344 (F344) rats, motor neuron (MN) death and denervation effects are becoming increasingly implicated in sarcopenia. We have previously demonstrated that MN loss and muscle weakness are prevalent in respiratory MNs and muscles; however, the chronology and mechanism of MN death and muscle weakness are relatively unexplored. We evaluated inflammaging (inflammatory cytokine release via ELISA), the endoplasmic reticulum (ER) stress response (via western blotting), mitochondrial degeneration (via serial block-face scanning electron microscopy), mitochondrial function (via SDH

Lysosomes function as metabolic control centers that integrate degradation, nutrient sensing, and stress signaling. In neurons, which must maintain proteostasis and energetic balance throughout life, lysosomal homeostasis determines cellular resilience. Emerging evidence identifies lysosomal injury and defective repair as common denominators across neurodegenerative diseases. Damage to the lysosomal membrane caused by oxidative stress, lipid imbalance, or genetic mutations triggers a hierarchical quality control cascade. Early lesions recruit the endosomal sorting complex required for transport (ESCRT) machinery for mechanical resealing, while larger ruptures activate lipid-centered recovery modules. When repair fails, lysophagy eliminates irreparable organelles and a TFEB-dependent transcriptional program regenerates the lysosomal pool. These tightly coupled responses safeguard neurons from catastrophic proteostatic collapse. Their impairment, through mutations in lysosomal proteins, or through aging, produces the lysosomal fragility that underlies Alzheimer disease, Parkinson disease, amyotrophic lateral sclerosis/frontotemporal dementia, and Huntington disease. Crosstalk between lysosomes, mitochondria, and ER integrates local damage with systemic metabolic adaptation, while dysregulated lysosomal exocytosis and inflammation propagate pathology. Understanding how ESCRT complexes, lipid transport, and transcriptional renewal cooperate to preserve lysosomal integrity reveals unifying principles of neurodegeneration and defines molecular targets for intervention. Restoring lysosomal repair and renewal offers a rational path toward preventing neuronal loss.

Inflammatory aging is a key contributor to the onset and progression of rheumatoid arthritis (RA). The deubiquitinase Myb-like, SWIRM, and MPN domain-containing protein 1 (MYSM1) is known to play a crucial role in DNA damage repair and inflammatory aging, however, the precise mechanisms by which it exerts these effects remain unclear. This study aimed to investigate the relationship between MYSM1 expression in peripheral blood mononuclear cells (PBMCs) and DNA damage-induced inflammatory aging in RA patients, elucidating its potential role in RA pathogenesis.

Aging is typically accompanied by a progressive decline in cognitive function, yet some individuals maintain exceptional cognitive performance, even across the transition from middle to older age, defining exceptional cognitive resilience. While existing measures of resilience primarily rely on clinical assessments, its molecular determinants and early predictive markers remain poorly understood. Here, we performed untargeted LC-MS/MS profiling of longitudinal serum samples to identify metabolic signatures associated with cognitive resilience, which was established based on cognitive tests conducted over 28 years in a cohort of 237 participants. We observed associations across multiple chemical classes, including carnitines, glutamine conjugates, phosphocholines, as well as diet- and drug-derived metabolites. Chemical class-specific analyses revealed distinct metabolic profiles, including predominantly negative associations of medium-chain acylcarnitines with cognitive resilience, increased accumulation of glucuronide conjugates in individuals with low cognitive resilience, altered metabolism of the antihypertensive drug, metoprolol, and elevated levels of dietary compounds such as piperine and lutein in individuals with high cognitive resilience. By leveraging public metabolomics data, we further contextualized the metabolic signatures with respect to their organ specificity, microbial origin, and disease associations. Collectively, these metabolic features, including several previously underexplored compounds, represent promising candidates for functional characterization in mechanisms of aging biology and provide mechanistic insights into the molecular basis of cognitive resilience.

Overactivation of memory networks and pathways can induce post-traumatic stress disorders and memory generalization, where memories are recalled in inappropriate situations. Here, we demonstrate that age-related defects in long-term memories in Drosophila are also caused by memory generalization. Aversive memory engram cells are formed in both young and old flies trained in an odor avoidance task. However, while engrams in young flies are activated specifically by odors previously paired with electrical shocks, engrams in old flies are activated by shock-paired, unpaired, and novel odors. This enhancement of engram cell activation occurs because of increased activity of dopaminergic neurons during memory consolidation in old flies. Increased dopamine signaling results from an inability of old flies to inhibit glutamatergic activation and leads to increased activation of dopamine D2 receptors on engram cells. Our data suggest that increased dopaminergic activity after training generalizes the responsiveness of engram cells to disrupt appropriate memory recall.

Gonadotropins, follicle-stimulating hormone (FSH) and luteinizing hormone (LH), mediate critical reproductive functions via the hypothalamus-pituitary-gonadal axis. Their levels fluctuate across the lifespan, particularly during puberty and menopause, and across the menstrual cycle. In addition to peripheral expression, gonadotropin receptors are widely expressed in the brain, notably in memory-associated regions such as the hippocampus and cortex. Alterations in FSH and LH during reproductive transitions correlate with structural and functional brain changes. Puberty disorders, including central precocious puberty (CPP) and congenital hypogonadotropic hypogonadism (CHH), show altered gray and white matter and functional connectivity in the default mode network (DMN), which supports memory and is disrupted early in Alzheimer's disease (AD). Although preclinical evidence implicates gonadotropins in amyloid and tau pathology, studies of attention and memory have yielded inconsistent results. However, reproductive disorders such as primary ovarian insufficiency (POI) and polycystic ovary syndrome (PCOS) are associated with deficits in cognitive performance, altered DMN dynamics, and increased AD risk. Menopause, characterized by marked gonadotropin elevation, is also accompanied by alterations in brain structure, connectivity, amyloid and tau deposition, and cognition, with associations with FSH and LH that are underexplored. This review synthesizes a broad range of basic and clinical evidence across reproductive transitions and disorders, highlighting shared and distinct mechanisms by which gonadotropins influence brain development, aging, and AD risk, and suggesting directions for future research.

Frailty poses a significant challenge to aging societies, with increasing attention being paid to the concept of frailty transitions. Worsening frailty transitions are associated with higher risks of hospitalization, increased mortality, and substantial healthcare costs. Although frailty is influenced by multiple factors, the specific contributors to worsening transitions remain unclear due to interdependent and nonlinear relationships among physical, psychological, and social factors. Machine learning, which can effectively identify nonlinear patterns in health data, has been underutilized in this context.

Existing studies suggest that foods rich in phytoestrogens could reduce mortality and protect against the shortening of telomere length (TL). However, the specific phytoestrogens responsible for this effect remain unidentified. We conducted a cross-sectional study using data from the 1999-2002 U.S. National Health and Nutrition Examination Survey. Four metabolites of soy isoflavones (daidzein, equol, genistein, O-DMA) and two metabolites of lignans (enterodiol and enterolactone) were detected. Leukocyte TL was measured. After ln-transformed, the association of phytoestrogen metabolites and leukocyte TL were assessed using multivariable linear regression. Percentage change was calculated as (eβ-1) × 100%. Of the 2,607 participants, 48.52% were male. A 1-SD increase in urinary equol was associated with a 1.50% (95% CI: 0.51-2.50) increase in TL, and TL was 4.26% (95% CI: 1.07-7.56) longer in the highest quintile of equol compared to the lowest. Similarly, a 1-SD increase in the equol-to-daidzein ratio was linked to a 1.87% (95% CI: 0.91-2.84) rise in TL, and TL was 4.83% (95% CI: 1.71-8.05) longer in the highest quintile of the equol-to-daidzein ratio compared to the lowest. No significant association of urinary daidzein, genistein, O-DMA, enterodiol, and enterolactone with TL was observed. Our findings suggested that higher levels of urinary equol and its ratio with daidzein were associated with longer leukocyte TL, highlighting the need for further research into their relationship with aging.

Ageing is characterized by complex biological processes reflected in cellular and molecular changes. Mitochondria, which are crucial for energy production and cellular homeostasis, are particularly vulnerable to age-related deterioration. The number of copies of mitochondrial DNA (mtDNAcn) varies across and within tissues in response to energetic activity and mtDNA integrity, and is related to health and physical performance. Age-related changes in mtDNAcn can be difficult to study due to differential survival of phenotypes into older ages, but studies of changes in mtDNAcn within individuals are very limited. In this study, we investigated changes in red blood cell mtDNAcn across the life course within individual zebra finches (Taeniopygia guttata), a well-established avian model, from the nestling stage into old age. Our findings revealed a pronounced decline in relative mtDNAcn during post-natal development, followed by comparative stability throughout adulthood. This pattern was remarkably consistent among individuals. We found no significant relationship between variation in mtDNAcn and growth during the nestling period. However, based on measurements of disturbed take-off speed in late adulthood, we found that individuals with higher physical performance at that stage had higher relative mtDNAcn, suggesting a link between variation in individual bioenergetics and biological state.

Brain aging is accompanied by profound cellular and microstructural changes that precede overt tissue loss, yet in vivo MRI studies largely emphasize macroscopic measures or isolated diffusion and relaxation metrics, providing limited insight into how cellular-scale tissue architecture is altered across the adult lifespan. Here, we apply multidimensional diffusion-relaxation MRI (MD-MRI) to map voxel-wise microstructural phenotypes in cognitively unimpaired adults spanning early adulthood to late life (23-77 years). Rather than relying on predefined compartment models, MD-MRI resolves continuous voxel-wise distributions in a joint diffusion-relaxation space, enabling an integrated, model-free description of how cellular shape, size, restriction, and chemical environment vary with age. Using this approach, we reveal age-related multilateral shifts within a complex microstructural landscape, marked by increasing heterogeneity and disorder across brain tissue. With age, cellular-scale features showed a systematic transition from small to larger length-scale structures accompanied by reduced microscopic restriction, indicating a loss of fine cellular barriers and expansion of extracellular space. In parallel, we show tissue-dependent alterations in fast-relaxing properties aligned with known gray- and white-matter aging processes, including iron accumulation and myelin loss. Together, these findings indicate that normative brain aging involves progressive reorganization of structure and composition at the cellular level, rather than uniform shifts in bulk tissue properties. By decoupling cellular-scale shape, size, restriction, and chemical environment in vivo, MD-MRI identifies increasing cellular heterogeneity and breakdown of microscopic restriction as central features of human brain aging and provides a biologically interpretable framework for linking microstructural reorganization to age-related functional decline.

Fracture repair remains a significant clinical challenge in orthopedics, particularly in aging populations. Accumulating evidence indicates that cellular senescence critically modulates the fracture microenvironment via the senescence-associated secretory phenotype (SASP). The SASP constitutes a complex secretory program of senescent cells that releases pro-inflammatory cytokines, growth factors, and matrix-modifying enzymes to reshape the surrounding microenvironment. Rather than being a random collection of molecules, the SASP represents a coordinated signaling network that can either promote tissue repair or drive chronic inflammation depending on its context. In this review, we apply a systematic SASP classification to the canonical four phases of fracture healing to clarify their distinct roles across these stages. During the inflammatory phase, SASP-associated (but non-exclusive) inflammatory cytokines and chemokines potentiate innate immune cell recruitment and early host defense, thereby initiating the repair cascade; in the soft-callus phase, chemotactic and angiogenic SASP components (such as CCL2, PDGF, VEGF) position mesenchymal progenitors and support chondrogenesis and neovascularization; in the hard-callus phase, osteoinductive growth factors and matrix-acting proteases (such as TGF-β, IGFBPs, MMP-9/13) promote cartilage-to-bone conversion and early mineral deposition; and in the remodeling phase, regulated SASP-mediated matrix changes couple osteoclast resorption with osteoblast formation, while sustained pro-inflammatory or profibrotic signals may hinder the fine remodeling of the structure. This stage-resolved framework elucidates the dual nature of SASP, with transient activation facilitating repair and sustained overproduction leading to impaired remodeling. This framework provides a conceptual basis for developing stage-specific interventions to enhance bone repair. Notably, many mediators discussed here overlap with the broader injury-induced inflammatory secretome and are not senescence-exclusive; where possible, we emphasize senescent-cell-enriched contributions and regulatory circuits rather than implying unique cellular origins.

Cellular senescence of bone marrow mesenchymal stem cells (BMSCs) represents the fundamental pathological barrier to healing in osteoporotic patients. This study reports a multifunctional bone scaffold specifically designed to reverse this senescent phenotype by upregulating Slc25a33 and Crabp1, key regulators of mitochondrial biogenesis and retinoic acid signaling. The scaffold features interconnected spindle-shaped pores (long axis ∼100 μm) inspired by trabecular bone canalicular lacunae, combining polylactic acid nano-oriented fibers and Type I collagen to simulate rod-like and plate-like trabeculae. This biomimetic design enhances mechanical performance (Young's modulus: 51.478 ± 0.993 MPa, porosity: 65.341 ± 0.863%), facilitates cell migration and substance exchange, and continuously provides Type I collagen to the microenvironment. In vitro scaffold extracts reversed senescence in aged BMSCs, enhancing proliferation (wound closure: 42.46 ± 8.47% vs 39.51 ± 4.35%,

Age-related musculoskeletal diseases underscore the importance of comprehensive dietary interventions. The individual benefits of calcium β-hydroxy-β-methylbutyrate (CaHMB), colostrum basic protein (CBP), and hyaluronic acid (HA) on the musculoskeletal system have been well documented; however, their combined effects remain unclear. This study aims to investigate the effects of combined supplementation with CaHMB, CBP, and HA on age-related musculoskeletal degeneration and to explore the underlying mechanisms, with a particular focus on the muscle-bone axis. Twelve-month-old male C57BL/6J mice received a 6-month dietary intervention. The combination (COM) group was supplemented with CaHMB, CBP, and HA at substantially reduced doses (37.5%, 20%, and 14%, respectively). The COM group showed higher lean mass (18%) and a greater muscle cross-sectional area (35%) compared to the OLD group, with significantly enhanced grip strength by 41% and exercise performances. The COM group presented less decline in whole-body bone mineral density (5%) than the OLD group. The bone microstructure was improved by increasing the bone volume fraction and trabecular thickness/number, while a decrease in trabecular separation was observed in the COM group. Musculoskeletal improvements either matched or surpassed the benefits of individual components. Mechanistically, interventions modulated the key mediators of the muscle-bone axis, significantly upregulating beneficial myokines (irisin and IGF-1) and osteokine osteocalcin, while downregulating negative regulators (myostatin and sclerostin). These changes were correlated with the observed phenotypic enhancements. The low-dose combination of CaHMB, CBP, and HA provides comprehensive benefits against age-related muscle and bone loss, likely by modulating the muscle-bone axis, and outperforms individual components. Our findings support its potential as a multi-targeted nutritional strategy for the aging population.

Mitochondria are central to cellular homeostasis and play a critical role in aging and age-related disorders, making them promising therapeutical targets. Here, we identify terbinafine and miglustat as novel mitochondrial stress inducers that extend lifespan and improve healthspan in Caenorhabditis elegans. Through a two-step screening, we found that both compounds activate the mitochondrial stress response (MSR) and exhibit distinct mechanisms of action. Terbinafine and miglustat robustly activated the mitochondrial unfolded protein response (UPRmt) mediator ATFS-1, upregulated MSR pathways, and modulated mitochondrial function across species, similarly to doxycycline. Interestingly, both compounds also engaged the insulin/IGF-1 signaling (IIS) pathway in C. elegans, revealing an integrated stress response involving coordinated action of ATFS-1 and the FOXO transcription factor DAF-16, distinct from canonical IIS activation. Experiments in human HEK293T cells confirmed the translational potential, with both compounds inducing mitochondrial stress and modulating mitochondrial function in mammalian systems. This study highlights the potential of harnessing the MSR to promote longevity and mitigate age-related functional decline. The identification of terbinafine and miglustat as mitochondrial stressors paves the way for novel anti-aging therapies.

Micro- and nano-plastics (MNPs) contamination has recently become a widespread concern. These particles have been detected in multiple human organs. MNPs can enter the human body through three ways: diet intake, inhalation and skin contact, subsequently entering the bloodstream and distributing throughout the body's tissue systems. The health risks posed by MNPs exposure are believed to be linked to cellular senescence, a state of stable cell growth arrest that significantly increases the risk of age-related diseases. The mechanisms of MNPs-induced cellular senescence are primarily associated with oxidative stress and DNA damage, and involve signaling pathways such as eNOS/SIRT1, cGAS-STING, and NF-κB. In this review, we examine the exposure pathways and distribution of MNPs in the human body, the characteristics and mechanisms of MNPs-induced cellular senescence, and potential therapeutic interventions to counteract these effects. We aim to provide state-of-the-art information on the mechanism of MNPs-induced cellular senescence and preventive and curative measures, thereby stimulating future research to minimize the health hazards of their exposure.

Age-related cognitive impairment affects the quality of life of the elderly, contributing to a substantial healthcare burden. Ginsenoside Rb1 (Rb1), an active component of ginseng, has been shown to possess various biological functions, including antisenescence, anti-inflammatory, and neuroprotection effects. This study investigated whether Rb1 attenuates age-related cognitive impairment and aimed to elucidate the relevant molecular mechanism.

Loss of skeletal muscle mass and strength are common manifestations of frailty in older people and are linked to reduced quality of life. However, whether mitochondria are mechanistically linked to frailty and how physical activity, or lack thereof, is involved in age-related functional decline are still unknown. We report that exercise-induced improvements in functional capacity, including reduced frailty in old mice, are dependent on mitochondrial adaptations in skeletal muscle at structural, enzymatic, and functional levels. Our preclinical study included a healthy aging mouse line, a transgenic model of robustness, and a muscle-specific mitochondrial-deficient mutant mice, allowing us to assess both mitochondrial plasticity with aging and the necessity of intact mitochondrial function for exercise-induced adaptations. These findings were corroborated by a cross-sectional human study examining the relationship between skeletal muscle mitochondrial function, age, and physical capacity. We analyzed biopsies from 30 donors (men and women, aged 17 to 99 y) stratified into young and older adults with varying functional statuses. Our results indicate that mitochondrial dysfunction in skeletal muscle is associated with the decline in locomotor muscle function in the elderly, highlighting the potential role of exercise or habitual physical activity in mitigating this phenotype. Notably, we demonstrate that skeletal muscle mitochondria maintain plasticity during aging in mice and humans, and that this preserved adaptability can be leveraged to improve muscle performance and overall functional capacity.

Autophagy, a highly conserved cellular degradation process, plays essential roles in various physiological processes including aging. Though autophagy is required for lifespan extension in multiple longevity paradigms, the tissue-specific roles of autophagy-related genes (atgs) in longevity remain incompletely understood. Here, we investigate the tissue-specific requirements of atgs to promote longevity conferred by germline ablation (called gonadal longevity) using C. elegans. Remarkably, we discovered that neuronal or intestinal knockdown of atg-18, but not other atgs, specifically abolished gonadal longevity, although knockdown of all tested atgs effectively inhibited autophagic activity in these targeted tissues, implying the presence of an autophagy-independent function of ATG-18 in gonadal longevity. We demonstrated that germline deficiency triggered significant upregulation of ATG-18 in neurons and the intestine. From the proteomics analysis and subsequent screening, we found ATG-18 interacts with PCK-2, a phosphoenolpyruvate carboxykinase. PCK-2 is upregulated within the intestine of germline-deficient animals, but this depends on the non-autophagic function of ATG-18. Consistently, we showed that PCK-2 overexpression mediated longevity required ATG-18 but not its potential interacting partner to regulate autophagy, ATG-2. These findings reveal a previously unrecognized autophagy-independent role for ATG-18 in regulating lifespan in response to germline signals, expanding our understanding of how this evolutionarily conserved protein coordinates organism-wide responses to promote longevity.

Although atherosclerotic vascular disease (ASVD) and calcific aortic stenosis (AS) are distinct clinical entities, inflammation is a common driving force. The contribution of endogenous α-Klotho, an anti-aging protein, in the vasculature and aortic valve (AV) as an inflammatory mediator of such diseases remains unclear. We investigated α-Klotho expression using qPCR, ELISA, and immunohistochemistry in vascular (aorta, carotid, and femoral) and AV tissue samples from patients with ASVD (n = 112) and calcific AS (n = 172), respectively. We also determined circulating levels of soluble α-Klotho. We assessed α-Klotho associations with inflammatory and calcification markers. In vitro, we treated human vascular smooth muscle cells (VSMCs) and valve interstitial cells (VICs) with interleukin (IL)-1β and high-phosphate (HP) medium, respectively, and we evaluated the effects α-Klotho silencing and recombinant α-Klotho (rKlotho) supplementation. α-Klotho expression was significantly reduced in atherosclerotic vessels and stenotic AVs. Vascular expression varied across territories, with the lowest levels in the carotids. In stenotic AVs, α-Klotho expression was lower in fibro-calcified areas compared to "healthy" regions. Endogenous tissue α-Klotho and circulating soluble α-Klotho were inversely associated with local and systemic inflammatory markers and, in AVs, with osteogenic-related markers. In vitro, pro-inflammatory stimuli downregulated α-Klotho gene expression in VSMCs and VICs. α-Klotho silencing amplified inflammatory responses in both cell types and promoted VIC calcification, whereas rKlotho attenuated inflammation and inhibited osteogenic differentiation. These findings suggest endogenous α-Klotho plays a central role in the inflammation underlying ASVD and calcific AS.

Cellular senescence of white adipose tissues (WAT) represents an early hallmark of aging; however, the involved mechanisms remain incompletely understood. Here, we identified the cytosolic phosphoenolpyruvate carboxykinase (Pck1) as a key regulator of mitochondrial function and inflammaging in WAT. Pck1 expression was downregulated in both gonadal WAT and inguinal WAT during aging, and adipocyte-specific Pck1 deficiency accelerated inflammaging and metabolic disorders. Untargeted metabolomic and isotope-tracing analyses revealed that loss of Pck1 impaired cataplerosis, the export of tricarboxylic acid (TCA) cycle intermediates, resulting in accumulation of fumarate in adipocytes. Supplementation with exogenous fumarate disrupted mitochondrial homeostasis of adipocytes, promoted oxidative stress and triggered cytosolic release of mitochondrial DNA (mtDNA), leading to the activation of the cyclic GMP-AMP synthase/stimulator of interferon genes (cGAS/STING) signaling pathway that may contribute to inflammaging and chronic obesity. These were phenocopied with Pck1-deficient adipocytes. Conversely, overexpression of fumarate hydratase (Fh1) reduced fumarate level substantially and attenuated adipocyte inflammaging. Collectively, these findings identify Pck1 as a pivotal regulator of mitochondrial metabolic homeostasis and suggest that targeting Pck1 may represent a promising therapeutic strategy for age-related diseases.

Insulin-like growth factor-1 (IGF-1) signaling plays a paradoxical role in aging, acting as both a mediator of tissue repair and a driver of chronic inflammation through the senescence-associated secretory phenotype (SASP). In this review, we propose a biphasic senescence switch model in which the temporal pattern of IGF-1 exposure, acute versus chronic, determines cellular fate. Transient IGF-1 signaling supports homeostasis and repair, whereas sustained activation promotes stable senescence via reactive oxygen species (ROS)-mediated DNA damage, p53/p21 pathway activation, and a potent pro-inflammatory SASP. Central to this process is IGF-binding protein-5 (IGFBP-5), which amplifies senescence in vascular and stromal cells by linking coagulation and inflammatory signals to p53-dependent arrest. The contrasting human conditions of IGF-1 deficiency (Laron syndrome) and excess (acromegaly) illustrate the lifespan and disease risks associated with dysregulated IGF-1 signaling. Emerging evidence highlights the role of extracellular vesicles in bypassing soluble IGFBP regulation, enabling paracrine propagation of senescence even under systemic IGF-1 modulation. Ultimately, we position the IGF-1/IGFBP axis as a prime target for precision senomodulation, advocating for combined strategies that temporally tune endocrine signaling with senolytic and senomorphic therapies to mitigate chronic inflammation, delay age-related dysfunction, and extend healthspan.

This cross-sectional study examined associations between postmenopausal stage (early and late), arterial stiffness, and cardiorespiratory fitness. A total of 125 postmenopausal women (58.07 ± 6.61 years) underwent carotid-femoral pulse wave velocity assessment (SphygmoCor, Atcor). A subset of 96 women (57.20 ± 6.42 years) completed an estimated maximal oxygen uptake testing, using a Monark Ergomedic 839E cycle ergometer. Multiple stepwise regressions identified predictors of arterial stiffness and cardiorespiratory fitness. Compared with late postmenopause, early postmenopausal women showed lower arterial stiffness (-0.71 ± 0.29 m/s, p = 0.02) and systolic blood pressure (-6.40 ± 3.06 mmHg, p = 0.04), indicating a relative difference within postmenopause. Early postmenopause also showed higher cardiorespiratory fitness levels than late postmenopause. Moreover, body fat percentage was inversely associated with cardiorespiratory fitness in +1c substage, and visceral fat level displayed inverse associations with cardiorespiratory fitness in late postmenopause. In the +1a substage, hormone therapy was positively associated with cardiorespiratory fitness in exploratory model. Within postmenopause, early postmenopause showed lower arterial stiffness and systolic blood pressure than late postmenopause, and blood pressure and adiposity emerged as key correlates of vascular stiffness and fitness. While causal inference is precluded by the cross-sectional design, the results support stage-targeted strategies emphasizing BP control, body-composition management, and exercise to help preserve vascular and functional health in women after menopause.

At present, there are no FDA-approved orally-available bone anabolic agents to treat osteoporosis. PTH stimulates bone formation through an intracellular signaling cascade that involves the inhibition of salt-inducible kinase (SIK) isoforms 2 and 3. Therefore, direct small molecule SIK2/SIK3 inhibitors may represent a strategy to mimic PTH actions to treat different forms of osteoporosis. We previously described the synthesis and characterization of SK-124, a pharmacologic SIK2/SIK3 inhibitor that increases trabecular bone formation in eugonadal mice. However, the efficacy of this agent in osteoporosis mouse models remains unknown. Hypogonadism is an important cause of age-related bone loss. In this study, we investigated the therapeutic potential of SK-124 in a male hypogonadal bone loss model (orchiectomy, ORX) in BALB/c mice. Radiographic and histological analyses revealed that SK-124-treated ORX mice showed reduced bone loss compared to the vehicle-treated ORX mice. Serum bone turnover markers demonstrated that SK-124 treatment increased bone turnover, suggesting that SK-124 acts in a PTH-like manner in ORX mice. Bone RNA-sequencing analysis demonstrated novel pathways associated with increased bone formation in response to SK-124 treatment. These findings indicate that SK-124 prevents bone loss in a hypogonadal bone loss model and holds potential as an orally available therapeutic for treating osteoporosis due to testosterone deficiency.