Longevity Papers

The naked mole rat (NMR, Heterocephalus glaber) is a eusocial rodent that is native to northeastern Africa. NMRs exhibit extraordinary traits such as longevity, resistance to age-related decline, and remarkable hypoxia tolerance. Although the reference genome of this species has been determined because of its unique characteristics, the significance or role of intraspecific genomic variations remains unknown. In this study, we used PacBio long-read sequencing to generate a genome assembly of NMR reared in Japan. The assembled genome is 2.56 Gb. Benchmarking Universal Single-Copy Orthologs (BUSCO) revealed high completeness (95.2%). BRAKER3 estimated 26,714 protein-coding genes, and we successfully added functional annotations for 26,232 protein-coding genes using the functional annotation workflow. We identified 417 gene models that were previously undetectable in the reference genome of this species. We also identified structural and amino acid sequence variations between our assembly and the reference genome, suggesting the presence of intraspecific genomic variations. This new genomic resource could help uncover the molecular mechanisms underlying the behavioral and physiological traits of NMR.

The skin is a complex organ composed of multiple layers and diverse cell types, including keratinocytes, fibroblasts, adipocytes, and sensory neurons, which maintain its structural and functional integrity together. Conventional in vitro and ex vivo models help investigate drug permeation and selected biological effects. However, they are limited in replicating neural interactions critical for assessing the efficacy of neuropeptide-based therapies. To address this limitation, a sensory neuron-integrated skin spheroid (SS) model was established, incorporating key skin cell types and providing a rapid, adaptable, and physiologically relevant platform for screening the biological activity of topical delivery systems targeting neuronal pathways. The model's responsiveness was demonstrated using acetyl hexapeptide-3 (HEX-3), a neuropeptide that inhibits acetylcholine release. HEX-3 was internalized by spheroid cells, with preferential accumulation around sensory neurons, confirming targeted cellular uptake. In parallel, ex vivo human skin studies confirmed that HEX-3 can traverse the stratum corneum and accumulate in deeper layers. Treatment with this film enhanced skin hydration, reduced scaling, and improved the structural organization of the stratum corneum after 48 h. Functional assays using the SS model showed that HEX-3 treatment suppressed acetylcholine release, upregulated the antioxidant enzyme SOD2, and stimulated type I collagen synthesis. In aged skin samples, the application of HEX-3 significantly increased collagen levels. This effect was mirrored in the spheroid model, which reached collagen levels comparable to those of aged human skin upon treatment. These findings establish the SS model as a robust platform for evaluating the biological activity of neuropeptide-based topical therapies, offering valuable insights for developing advanced strategies for skin rejuvenation and repair.

Epigenetic regulation, including DNA methylation and histone modifications, play a pivotal role in shaping T cell functionality throughout life. With aging, these epigenetic changes profoundly affect gene expression, altering T cell plasticity, activation, and differentiation. These modifications contribute significantly to immunosenescence, increasing susceptibility to infections, cancer, and autoimmune diseases. In CD8⁺ T cells, chromatin closure at key regulatory regions suppresses activation and migration, while chromatin opening in pro-inflammatory gene loci amplifies inflammation. These changes drive terminal differentiation, characterized by increased expression of senescence-associated markers, impaired migration and loss of epigenetic plasticity. CD4⁺ T cells experience fewer but critical epigenetic alterations, including disrupted pathways, a skewed Th1/Th2 balance, and reduced Treg functionality. These epigenetic changes, compounded by metabolic dysfunctions, such as mitochondrial deficiency and oxidative stress, impair T-cell adaptability and resilience in the aging organism. Therefore, understanding the interplay between epigenetic and metabolic factors in T cell aging offers promising therapeutic opportunities to mitigate immunosenescence and enhance immune function in aging populations. This review explores the interplay between DNA methylation, histone alterations, and metabolic changes underlying T cell aging.

Idiopathic pulmonary fibrosis (IPF) is a fatal aging-related disease characterized by aberrant lung remodeling and progressive scarring, leading to organ failure and death. Current FDA approved anti-fibrotic treatments are unable to reverse established disease, highlighting the need for innovative therapeutic approaches targeting novel pathways and cell types. Mounting evidence, including our own, has recently highlighted the pathogenic role of aging-related endothelial abnormalities, including vascular inflammation and oxidative stress, in the progression of lung fibrosis, offering new therapeutic opportunities to block IPF progression. Unexplored, however, are the modalities to restore vascular abnormalities associated with progressive lung fibrosis, representing a critical gap to effective treatments for IPF. In this study, we demonstrate that circulating extracellular vesicles (cEVs) isolated from young mice are capable of reversing the aging-associated transcriptional alterations of the pulmonary vasculature, reducing transcripts associated with innate immunity, oxidative stress and senescence, while simultaneously increasing transcripts linked to endothelial identity. Using the bleomycin model of persistent lung fibrosis in aged mice, we then demonstrate that the pre-treatment with cEVs improves the vascular response to injury and attenuates lung fibrosis progression, as demonstrated by reduced lung collagen content and preserved vascular network and lung architecture. These findings support the efficacy of interventions targeting endothelial aging-associated transcriptional alterations, such as young cEV delivery, in mitigating pulmonary fibrosis progression in animal models of persistent fibrosis and indicate the potential benefits of combined therapies that simultaneously address vascular and non-vascular aspects of IPF.

Epigenome is sensitive to metabolic inputs and crucial for aging. Lysosomes emerge as a signaling hub to sense metabolic cues and regulate longevity. We unveil that lysosomal metabolic pathways signal through the epigenome to regulate transgenerational longevity in Caenorhabditis elegans. We discovered that the induction of lysosomal lipid signaling and lysosomal AMP-activated protein kinase (AMPK), or the reduction of lysosomal mechanistic-target-of-rapamycin (mTOR) signaling, increases the expression of histone H3.3 variant and elevates H3K79 methylation, leading to lifespan extension across multiple generations. This transgenerational pro-longevity effect requires intestine-to-germline transportation of H3.3 and a germline-specific H3K79 methyltransferase, and can be recapitulated by overexpressing H3.3 or the H3K79 methyltransferase. This work uncovers a lysosome-epigenome signaling axis linking soma and germline to mediate the transgenerational inheritance of longevity.

Body composition (adiposity and muscle depots) is strongly associated with cardiometabolic risk. However, using body composition measures for future disease risk prediction is difficult as they may reflect total body size or typical aging rather than poor health. We used data from the UK Biobank (UKB) and the German National Cohort (NAKO) to calculate age-, sex-, and height-specific z-scores for body composition measures (subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT), skeletal muscle (SM), SM fat fraction (SMFF), and intramuscular adipose tissue (IMAT)) and describe changes across the lifespan. Multivariable Cox regression assessed the prognostic value of z-score categories (low: z<-1; middle: z=-1 to 1; high: z>1) for incident diabetes, major adverse cardiovascular events (MACE), and all-cause mortality beyond traditional cardiometabolic risk factors in the UKB. Among 66,608 individuals (mean age: 57.7{+/-}12.9 y; mean BMI: 26.2{+/-}4.5 kg/m2, 48.3% female), SAT, VAT, SMFF, and IMAT were positively, and SM negatively associated with age. In multivariable-adjusted Cox regression, z-score risk categories had hazard ratios of up to 2.69 for incident diabetes (high VAT category), 1.41 for incident MACE (high IMAT), and 1.49 for all-cause mortality (low SM) compared to middle categories. Body composition shows distinct age-related changes across the lifespan. Z-scores of age-, sex-, and height-adjusted body composition measures identify individuals at risk and predict cardiometabolic outcomes and mortality beyond traditional risk factors. Our open-source tool facilitates the clinical translation of age-specific body composition assessments and supports future research.

Rationale: Idiopathic pulmonary fibrosis (IPF) is a progressive, age-associated, lung disease characterized by short telomeres in alveolar type 2 (AT2) cells, epithelial remodeling, and fibrosis. Objectives: This study investigated how telomere dysfunction in AT2 cells lacking Telomere Repeat Binding Factor 1 (TRF1) drives lung remodeling in SPC-creTRF1flox/flox mice and its relevance to IPF. Methods: Mouse model of telomere dysfunction was used to conditionally delete TRF1 in AT2 cells. SPC-creTRF1flox/flox mouse lung epithelial cells were used to perform single cell RNA sequencing. AT2 cells from IPF lungs were analyzed by single cell RNA sequencing in an organoid model. Measurements and Main Results: Single cell RNA-sequencing revealed distinct pathological AT2 cells enriched in DNA damage, senescence, oxidative stress, and pro-fibrotic genes, along with fewer normal AT2 cells and increased club cells in SPC-creTRF1flox/flox mice. Pathological AT2 cells showed different early and late-stage gene signatures, with a prominent p53 signature at both time-points. Genetic deletion of p53 in SPC-creTRF1flox/flox AT2 cells improved survival and prevented lung fibrosis. p53 deletion or inhibition improved organoid formation, surfactant protein C expression, and reduced pro-fibrotic gene expression in AT2 cells isolated from SPC-creTRF1flox/flox mice or IPF lungs. Conclusions: These data suggest that the DNA damage response to AT2 cell telomere dysfunction, driven by enhanced p53 activity, mediates early AT2 cell transdifferentiation and senescence, leading to epithelial cell remodeling and fibrosis and that reversing this reprogramming is a potential therapeutic approach for managing IPF.

Aging is a complex biological process that detrimentally affects the brain and cerebrovascular system, contributing to the pathogenesis of age-related diseases like vascular cognitive impairment and dementia (VCID) and Alzheimer's disease (AD). While cell-autonomous mechanisms that occur within cells, independent of external signals from neighboring cells or systemic factors, account for some aspects of aging, they cannot explain the entire aging process. Non-autonomous, paracrine and endocrine, pathways also play a crucial role in orchestrating brain and vascular aging. The systemic milieu modulates aging through pro-geronic and anti-geronic circulating factors that mediate age-related decline or confer rejuvenative effects. This review explores the impact of systemic factors on cerebrovascular and brain aging, with a particular focus on findings from heterochronic parabiosis, blood exchange, and plasma transfer experiments. We discuss how these factors influence fundamental cellular and molecular processes of aging and impact cerebrovascular endothelial function, neurovascular coupling mechanisms, blood-brain barrier integrity, neuroinflammation, capillary density, and amyloid pathologies, with significant consequences for cognitive function. Additionally, we address the translational potential and challenges of modifying the systemic milieu to promote brain health and prevent age-related cognitive impairment.

Small extracellular vesicles (sEV) derived from mesenchymal stem cells hold promise for anti-skin aging, yet their clinical application is hindered by poor transdermal permeability. Herein, we report an innovative light-controlled sEV-based spherical nucleic acid nanomotor (NM-ESNA). This nanosystem was composed of an sEV core and an MMP1-targeting siRNA shell, forming a 3D penetrative nanostructure. In addition, asymmetrically modified light-responsive gas-generating molecules were integrated into the nanomotor, enabling efficient dermal delivery. The light-controlled and enhanced transdermal delivery guaranteed synergistic anti-skin aging therapy through sEV-mediated paracrine effects and gene therapy targeting MMP1 in the dermis. On the basis of this deep transdermal delivery technology and the synergistic therapy strategy, NM-ESNA demonstrated outstanding anti-skin aging effects in a mouse model. This biocompatible nanosystem (NM-ESNA) enabled light-controlled and deep transdermal delivery, establishing a therapeutic platform with significant potential for sEV-based noninvasive anti-skin aging therapy.

Telomere repeat-containing RNA (TERRA) is transcribed at telomeres and forms RNA-DNA hybrids. In budding yeast, the presence of RNA-DNA hybrids at short telomeres promotes homology-directed repair (HDR) and prevents accelerated replicative senescence. RNA-DNA hybrids at telomeres have also been demonstrated to prevent 5'end resection, an essential step for HDR. In accordance, we now demonstrate that, not only the presence, but also the removal, of RNA-DNA hybrids drives HDR at shortened telomeres during replicative senescence. Although RNase H2 is absent from short telomeres, it is quickly compensated for by the recruitment of RNase H1 and Sen1. The recruitment of RNase H1 is essential to allow for the loading of Rad51, consistent with the notion that RNA-DNA hybrids prevent Exo1-mediated end resection. In the absence of RNase H1 or Sen1 function, yeast cultures prematurely enter replicative senescence in the absence of telomerase. Furthermore, the delayed senescence phenotype observed when RNase H2 is deleted, depends on the presence of RNase H1 and Sen1. This study demonstrates the importance of transient RNA-DNA hybrids at short telomeres to regulate senescence.

Dietary restriction (DR), whether applied during adulthood or juvenile stages, extends lifespan across diverse species. However, the mechanisms by which early-life dietary interventions influence adult physiology and longevity remain poorly understood. Here, using Drosophila as a model, we demonstrate that protein restriction during the larval stage (early-life protein restriction, ePR) promotes adult lifespan by reducing storage protein levels. Stable isotope tracing reveals that dietary amino acids obtained in the larval stage are retained into adulthood, especially incorporated into ribosomal proteins. This is mediated by larval serum protein 2 (Lsp2), a major storage protein, whose expression is durably downregulated by ePR. Both dietary (ePR) and genetic (Lsp2-RNAi) reduction of the protein storage lead to decreased ribosomal protein levels and translation activity in early adulthood. Notably, these storage proteins are enriched in aromatic amino acids such as tyrosine, and larval dietary tyrosine restriction alone is sufficient to suppress translation and promote longevity. These findings show that storage proteins mediate the effect of larval nutrition on adult longevity via controlling translation. Our study uncovers a previously unrecognized mechanism of nutritional memory that links early-life nutrition to adult physiology and lifespan.

This research investigates the complex biochemical mechanisms underlying aging by analyzing primary human fibroblasts using a longitudinal multi-omics dataset. This dataset includes cytology, DNA methylation and epigenetic clocks, bioenergetics, mitochondrial DNA sequencing, RNA sequencing, and cytokine profiling. Key findings indicate that mitochondrial efficiency declines with age, while glycolysis becomes more prevalent to compensate for energy demands. Epigenetic clocks, such as Hannum and PhenoAge, showed strong correlations with biological age ({rho} > 0.650, p < 1e-6), validating the experimental setup and confirming that the cultured fibroblasts were aging appropriately. Fibroblasts with SURF1 mutations exhibited accelerated aging, marked by bioenergetic deficits, increased cell volume, and reduced proliferative capacity, underscoring the pivotal role of mitochondrial dysfunction in cellular senescence. Novel insights were gained from analyzing cytokines like IL18 and PCSK9, some of which were linked to age-related diseases such as Alzheimer\'s and cardiovascular disorders. Experimental treatments revealed distinct effects on cellular aging. Dexamethasone reduced inflammation but also increased DNA methylation, induced metabolic inefficiencies, and shortened cellular lifespan. Oligomycin heightened oxidative stress and RNA degradation, emphasizing how such treatments contribute to cellular stress and metabolic imbalance while shedding light on aging mechanisms. By uncovering connections between mitochondrial dysfunction, epigenetic biomarkers, and immune dysregulation, this study identifies potential therapeutic targets for age-related diseases. Future research could validate the most promising biomarkers across diverse cell types and experimental treatments to build a more comprehensive understanding of aging.

Growing evidence suggests that the gut microbiota plays a key role in shaping life history in a wide range of species, including well-studied model organisms like Drosophila melanogaster. Although recent studies have explored the relationship between gut microbiota and female life history, the link between gut microbiota and male life history remains understudied. In this study, we explored the role of gut microbiota in shaping male life history traits by correlating variation in life history traits across genetically homogeneous isolines with their naturally occurring gut microbiota. Using 22 isolines from the Drosophila melanogaster Genetic Reference Panel (DGRP), we measured lifespan, early/late-life reproduction, and early/late-life physiological performance. We characterized the gut microbiota composition in young (5 days old) and old (26 days old) flies using 16S rDNA sequencing. We observed significant variation in male life history traits across isolines, as well as age-related changes in gut microbiota composition. Using machine learning, we showed that gut microbiota composition could predict the age of the organisms with high accuracy. Associations between gut microbiota and life history traits were notable, particularly involving the Acetobacter genus. In early life, the abundance of Acetobacter ascendens was associated with functional aging, while Acetobacter indonesiensis was linked to reproductive senescence. In late life, higher abundances of A. ascendens and Acetobacter pasteurianus were negatively associated with lifespan. These findings highlight the potential role of gut microbiota, especially the Acetobacter genus, in male fitness and aging.

Aging processes underlie common chronic cardiometabolic diseases such as heart failure and diabetes. Cross-organ/tissue interactions can accelerate aging through cellular senescence, tissue wasting, accelerated atherosclerosis, increased vascular stiffness, and reduction in blood flow, leading to organ remodeling and premature failure. This interorgan/tissue crosstalk can accelerate aging-related dysfunction through inflammation, senescence-associated secretome, and metabolic and mitochondrial changes resulting in increased oxidative stress, microvascular dysfunction, cellular reprogramming, and tissue fibrosis. This may also underscore the rising incidence and co-occurrence of multiorgan dysfunction in cardiometabolic aging in the population. Examples include interactions between the heart and the lungs, kidneys, liver, muscles, and brain, among others. However, this phenomenon can also present new translational opportunities for identifying diagnostic biomarkers to define early risks of multiorgan dysfunction, gain mechanistic insights, and help to design precision-directed therapeutic interventions. Indeed, this opens new opportunities for therapeutic development in targeting multiple organs simultaneously to disrupt the crosstalk-driven process of mutual disease acceleration. New therapeutic targets could provide synergistic benefits across multiple organ systems in the same at-risk patient. Ultimately, these approaches may together slow the aging process itself throughout the body. In the future, with patient-centered multisystem coordinated approaches, we can initiate a new paradigm of multiorgan early risk prediction and tailored intervention. With emerging tools including artificial intelligence-assisted risk profiling and novel preventive strategies (eg, RNA-based therapeutics), we may be able to mitigate multiorgan cardiometabolic dysfunction much earlier and, perhaps, even slow the aging process itself.

Skeletal muscle undergoes many alterations with aging. However, the impact of aging on muscle's ability to secrete myokines and its subsequent effects on the body remain largely unexplored. Here, we identify myokines that have the potential to ameliorate age-related muscle and bone decline. Notably, circulating levels of cardiotrophin-like cytokine factor 1 (CLCF1) decrease with age, while exercise significantly upregulates CLCF1 levels in both humans and rodents. Restoring CLCF1 levels in aged male mice improves their physical performance, glucose tolerance, and mitochondrial activity. Furthermore, CLCF1 protects against age-induced bone loss by inhibiting osteoclastogenesis and promoting osteoblast differentiation in aged male mice. These improvements mirror some of the effects of exercise training. Conversely, blocking CLCF1 activity significantly abolishes these beneficial effects, confirming the crucial role of CLCF1 in mediating the positive effects of exercise on muscle and bone health in male mice. These findings collectively suggest that CLCF1 may contribute to the regulation of age-associated musculoskeletal deterioration, and warrant further investigation into its potential role as a modulator of musculoskeletal health during aging.

T-cell metabolism is a key regulator of immune function. Metabolic dysfunction in T cells from young mice results in an aged phenotype, accelerating immunosenescence. Physical activity (PA) maintains T-cell function and delays immunosenescence in older adults, but the underlying mechanisms are poorly understood. We investigated the effects of PA on the metabolic and functional profiles at a single-cell resolution of resting and stimulated T cells from young adults (N = 9, 23 ± 3 years) and physically active older adults clustered between higher PA (HPA, N = 9, 75.5 ± 4.7 years) or lower PA levels (LPA, N = 10, 76.4 ± 2.1 years). Compared to young donors, HPA older adults had higher mitochondrial dependence (MD) and lower glucose dependence (GD) in unstimulated naïve, central memory (CM) and effector memory (EM) CD4

Physical exercise is critical for preventing and managing chronic conditions, such as cardiovascular disease, type 2 diabetes, hypertension, and sarcopenia. Regular physical activity significantly reduces cardiovascular and all-cause mortality. Exercise also enhances metabolic health by promoting muscle growth, mitochondrial biogenesis, and improved nutrient storage while preventing age-related muscle dysfunction. Key metabolic benefits include increased glucose uptake, enhanced fat oxidation, and the release of exercise-induced molecules called myokines, which mediate interorgan communication and improve overall metabolic function. These myokines and other exercise-induced signaling molecules hold promise as therapeutic targets for aging and obesity-related conditions.

With age, hematopoietic stem cells can acquire somatic mutations in leukemogenic genes that confer a proliferative advantage in a phenomenon termed CHIP. How these mutations result in increased risk for numerous age-related diseases remains poorly understood. We conduct a multiracial meta-analysis of EWAS of CHIP in the Framingham Heart Study, Jackson Heart Study, Cardiovascular Health Study, and Atherosclerosis Risk in Communities cohorts (N = 8196) to elucidate the molecular mechanisms underlying CHIP and illuminate how these changes influence cardiovascular disease risk. We functionally validate the EWAS findings using human hematopoietic stem cell models of CHIP. We then use expression quantitative trait methylation analysis to identify transcriptomic changes associated with CHIP-associated CpGs. Causal inference analyses reveal 261 CHIP-associated CpGs associated with cardiovascular traits and all-cause mortality (FDR adjusted p-value < 0.05). Taken together, our study reports the epigenetic changes impacted by CHIP and their associations with age-related disease outcomes.

Mitochondria play crucial roles in energy production, metabolism regulation, and cell death. Mitochondrial dysfunction is associated with many diseases, including cancers, aging, and neurodegenerative disorders. Consequently, developing methods for mitochondrial regulation and treating related diseases has garnered significant interest in biological and medical research. Here, a smart framework nucleic acid (FNA) strategy is presented for mitochondrial interference and targeted cell elimination. Our approach involves the design of tetrahedral DNA nanostructures (TDNs) modified with triphenylphosphine and single-stranded DNA sequences responding to specific nucleic acid biomarkers (e.g., microRNAs) presented in target cells. The interlinked DNA networks, formed in situ responding to specific biomarkers, enable targeting and enveloping of the mitochondria, leading to mitochondrial fragmentation and dysfunction. It is demonstrated that TDN-based FNAs targeted the cancer-associated microRNA (miR-21) may enhance the efficacy of cancer therapy by disrupting mitochondrial function, while also serving as carriers of anti-cancer drugs to reduce the side effects. Additionally, FNAs targeting the senescence-associated microRNA (miR-34a) specifically eliminate senescent cells in both cell and Caenorhabditis elegans models, thereby improving overall cell viability within mixed cell populations. This programmable and functionalized TDN-based platform opens new avenues for advancing anti-aging research and treating various diseases by achieving targeted cell elimination through mitochondrial interference.

Cognitive flexibility in the human brain engages dynamic interactions between the Default Mode Network (DMN) and the Fronto-Parietal Network (FPN), a functional architecture that is metabolically demanding and thus potentially susceptible to age-related decline. How the aging brain reorganizes its functional architecture to sustain cognitive flexibility under metabolic constraints remains an open question. In this study, we modeled resting-state functional flexibility across the adult lifespan (ages 18-88) using structural balance theory. Our findings align with the predictions of the SENECA model (Synergistic, Economical, Nonlinear, Emergent, Cognitive Aging), revealing a midlife neurocognitive transition: (i) from a metabolically costly, flexible DMN-FPN architecture, toward (ii) a more redundant configuration dominated by low-cost, sensory-driven interactions. The medio-parietal DMN and the Cingulo-Opercular Network (CON) are crucial to this transition, contributing to maintain global brain activity near a critical dynamic regime in older adulthood that optimizes for cognitive flexibility in face of declining metabolic resources. These findings advance a theoretical and methodological framework for understanding neurocognitive flexibility in aging and underscore the importance of multimodal fMRI-PET studies in midlife. They also open promising avenues for translational applications in neuropathology.

There is growing evidence that many perceptual difficulties associated with age-related hearing loss are not solely due to cochlear damage and are exacerbated by changes within the central nervous system. We examined electrophysiological (EEG) responses to clicks and diffusion kurtosis imaging (DKI) in 49 older (29 female) and 26 younger (20 female) adults to determine the extent to which auditory nerve (AN) deficits in older adults contributed to functional and structural changes throughout the auditory system. Older adults exhibited smaller AN responses, similar brainstem responses, and larger auditory cortex (AC) responses, demonstrating progressive central gain. Audiometric thresholds were not predictive of EEG measures. Reduced AN function predicted deficits in cortical microstructure (lower AC fractional anisotropy, FA) in older adults, consistent with myelin degeneration. These lower FA values in the AC of older adults also predicted larger AC responses and more central gain. Older adults exhibited significantly lower AC FA and higher mean diffusivity (MD) than younger adults, and AC FA and MD were significant predictors of speech-in-noise (SIN) recognition in older adults. The results suggest that reduced afferent input in older adults not only results in functional changes throughout the auditory system consistent with progressive gain, but also contributes to deficits in AC structure beyond those explained by age alone, contributing to SIN deficits. Understanding the complex effects of age, reduced AN input, central gain, and AC structure on SIN recognition may provide potential therapeutic targets for intervention.

Physical activity and mobility are critical for healthy aging and predict diverse health outcomes. While wrist-worn accelerometers are widely used to monitor physical activity, estimating gait metrics from wrist data remains challenging. We extend ElderNet, a self-supervised deep-learning model previously validated for walking-bout detection, to estimate gait metrics from wrist accelerometry. Validation involved 819 older adults (Rush-Memory-and-Aging-Project) and 85 individuals with gait impairments (Mobilise-D), from six medical centers. In Mobilise-D, ElderNet achieved an absolute error of 8.82 cm/s and an intra-class correlation of 0.87 for gait speed, outperforming state-of-the-art methods (p < 0.001) and models using a lower-back sensor. ElderNet outperformed (percentage error; p < 0.01) competing approaches in estimating cadence and stride length, and better (p < 0.01) classified mobility disability (AUC = 0.80) than conventional gait or physical activity metrics. These results render ElderNet a scalable tool for gait assessment using wrist-worn devices in aging and clinical populations.

Female reproductive aging is marked by a decline in oocyte quality, yet the underlying molecular mechanisms remain incompletely understood. Here, we used long-read direct RNA-sequencing to map transcript isoform changes in mouse ovaries across reproductive age. Comparing young and aged mice under controlled gonadotropin stimulation, we identified widespread alternative splicing changes, including shifts in exon usage, splice site selection, and transcript boundaries. Aged ovaries exhibited increased isoform diversity, favoring distal start and end sites, and a significant rise in exon skipping and intron retention events. Many of these age-biased splicing events altered open reading frames, introduced premature stop codons, or disrupted conserved protein domains. Notably, mitochondrial genes were disproportionately affected. We highlight Ndufs4, a Complex I subunit, as a case in which aging promotes a truncated isoform lacking the canonical Pfam domain. Structural modeling suggests this splice variant could impair Complex I assembly, providing a mechanistic link between splicing and mitochondrial dysfunction in the aging ovary. These findings support the existence of a splicing-energy-aging axis in ovarian physiology, wherein declining mitochondrial function and adaptive or maladaptive splicing changes are intertwined. Our study reveals that alternative splicing is not merely a byproduct of aging but a dynamic, transcriptome-wide regulatory layer that may influence oocyte competence and ovarian longevity. These insights open new avenues for investigating post-transcriptional mechanisms in reproductive aging and underscore the need to consider isoform-level regulation in models of ovarian decline.

Applicable methods of rejuvenating organisms and improving resistance to environmental stimuli are needed. During attempts to synchronize heart rates in unhealthy colonial chordates, we observed morphological rejuvenation. While the importance of endogenously generated bioelectric currents in development is well-established1,2, and exogenously applied current has shown promise in regenerative medicine3,4,5,6,7,8,9, a model that robustly increases longevity and fertility while providing detailed mechanistic insights has not been reported. Here, we report the establishment of such a model using pulsatile electrical current (PEC) in Botryllus schlosseri, an established colonial chordate model10,11,12,13,14,15. PEC treatment significantly improved survival, morphological integrity, stem cell mediated regeneration, and gonad production in Botryllus. Transcriptomic analysis revealed pathway changes associated with cellular metabolism, cell cycle, stem cell activity, DNA repair, and immune modulation. Notably, PEC-induced expression patterns resemble the exercise-induced macrophage-associated transcriptional response previously observed across several mammalian species16,17. This transcriptomic signature correlated with an increase in immune-cell-containing populations. These findings demonstrate that PEC can improve longevity, vitality, and reproduction in an established model renowned for defining broadly applicable biological principles. These studies offer insights into novel strategies for promoting healthy aging and organismal survival.

Background: Limbic white matter (WM) abnormalities are prevalent in aging and Alzheimer's disease (AD), yet their underlying biological mechanisms remain unclear. This study aims to identify the genetic architecture of limbic WM microstructure in older adults by leveraging harmonized data from multiple cohorts, including those enriched for cognitively impaired individuals. Methods: We analyzed diffusion MRI (dMRI) data from 2,614 non-Hispanic White older adults (mean age = 73.7 {+/-} 9.8 years; 57% female; 26% cognitively impaired) across 7 harmonized aging cohorts. WM microstructure was assessed in 7 limbic tracts, including the cingulum, fornix, inferior longitudinal fasciculus (ILF), uncinate fasciculus (UF), and transcallosal tracts of the inferior, middle, and superior temporal gyri (ITG, MTG, STG) using advanced diffusion MRI metrics corrected for free-water (FW): fractional anisotropy (FAFWcorr), axial diffusivity (AxDFWcorr), mean diffusivity (MDFWcorr), radial diffusivity (RDFWcorr). We performed heritability estimations, genome-wide association studies (GWAS) and post-GWAS analyses (genetic covariance, gene-level and pathway analysis, transcriptome-wide association [TWAS] studies). The AD relevance of the discovered variants was explored using bulk RNA-seq data from caudate, dorsolateral prefrontal, and posterior cingulate cortex human brain tissues. Results: Limbic WM microstructure demonstrated significant heritability (estimates between 0.26 and 0.60, pFDR < 0.05 for 15 of 35 tract-by-microstructure combinations). GWAS identified 6 genome-wide significant loci (p < 5.0x10-8) associated with WM microstructure. Notably, for MTG RDFWcorr, we identified a locus on chromosome 18 (lead SNP: rs12959877) comprising 38 SNPs that are eQTLs for CDH19, a gene involved in cell adhesion and highly expressed in oligodendrocytes. Other significant associations involved SNPs near KC6, SENP5, RORA, FAM107B, and MIR548A1. Bulk RNA-seq analyses revealed that brain tissue expression of RORA, FAM107B, and KC6 was significantly associated with cognitive decline and several AD pathologies (pFDR < 0.05). Post-GWAS analyses identified the genes SERPINA12 and DNAJB14, and highlighted the involvement of insulin signaling, immune response, and neurotrophic pathways. Genetic covariance analyses indicated shared genetic architecture between limbic WM and lipid profiles (e.g., HDL cholesterol), cardiovascular traits, and neurological conditions (e.g., multiple sclerosis) (pFDR < 0.05). Conclusion: This multi-cohort imaging genetics study identified several novel genes and biological pathways associated with limbic WM microstructure in an aging population enriched for cognitive impairment. The association of several identified genes with cognitive decline and AD pathology underscores their AD relevance. Our findings further suggest that the genetic underpinnings of limbic WM microstructure are linked to vascular health and inflammation, highlighting these pathways as promising avenues for future AD-related therapeutic development.

Moderate dietary restriction (DR) is known to extend lifespan, but its long-term safety remains unclear. In this study, silkworms of P50 were divided into libitum feeding (AL) and DR groups, with the DR group receiving 65% of the AL group's intake. Using the contemporary DR cohort as the parent generation, the identical dietary restriction methodology is perpetuated across successive generations to establish a multi-generational DR model. We recorded body weight, lifespan, spawning amount, and cocoon shell rate at each generation, and analyzed tissue sections of the G6 generation. Biochemical indices of hemolymph were assessed in the G0 and G3 generations, and the expression levels of genes associated with DR metabolism were analyzed using quantitative PCR. The result showed that DR initially caused weight loss, which then stabilized, and significantly extended lifespan. Biochemical indicators showed that silkworm's antioxidant capacity improved significantly in DR group, with notable differences between the current (G0) and successive (G3) generations. Gene expression related to oxidative stress was significantly altered depending on there function in G3 compared to G0. This suggests that long-term moderate DR can extend lifespan and reduce weight and fat, mainly due to enhanced antioxidant capacity. Additionally, animals demonstrated adaptability to prolonged moderate DR, indicating its feasibility across generations in insects. Our study confirms that boosting antioxidant capacity is a healthy, life-extending strategy under dietary restriction and highlights the adaptability of animals to such diets over generations, supporting the development of safe, long-term dietary plans for humans and large animals.

Iron-induced lipid peroxidation of phosphatidylethanolamine (PE) species is a key driver of ferroptosis in retinal pigment epithelial (RPE) cells, a process closely associated with age-related macular degeneration (AMD). The previous studies have demonstrated that induced retinal pigment epithelial (iRPE) cells generated by transcription factor-mediated reprogramming exhibit superior therapeutic efficacy in treating AMD. In this study, it is found that these iRPE cells are resistant to ferroptosis and further identified phosphoethanolamine/phosphocholine phosphatase 1 (PHOSPHO1) as a critical regulator underlying ferroptosis resistance. Mechanistically, PHOSPHO1 inhibits ferroptosis through two distinct mechanisms. First, it reduces PE levels in the endoplasmic reticulum, thereby limiting PE-derived lipid peroxidation. Second, it suppresses autophagy and ferritinophagy, leading to a reduction in intracellular free iron accumulation. Experiments using an in vivo rat model confirm that PHOSPHO1 effectively protects RPE cells from ferroptotic damage. These findings highlight PHOSPHO1 as a potential therapeutic target for AMD, providing insights into novel ferroptosis-based intervention strategies.

There is little understanding of how aging serves as the strongest risk factor for Alzheimer\'s disease (AD) and other neurological disorders. Specific neural cell types, such as microglia, undergo maladaptive changes with age, including increased inflammation, impaired debris clearance, and cellular senescence, yet specific mediators that regulate these processes remain unclear. The aged brain is rejuvenated by youth-associated plasma factors, including tissue inhibitor of metalloproteinases 2 (TIMP2), which we have shown acts on the extracellular matrix (ECM) to regulate synaptic plasticity. Given emerging roles for microglia in regulating plasticity and brain ECM dynamics, we examined the impact of TIMP2 on microglial function in the setting of aging. We show that TIMP2 deletion exacerbates microglial phenotypes associated with aging, including transcriptomic changes in cell activation, increased microgliosis, and increased levels of stress and inflammatory proteins measured in the brain extracellular space by in vivo microdialysis. Deleting specific cellular pools of TIMP2 in vivo increased microglial activation and altered myelin phagocytosis. Treating aged mice with TIMP2 reversed several phenotypes observed in our deletion models, resulting in decreased microglial activation, reduced proportions of proinflammatory microglia, and enhanced synapse phagocytosis. Our results identify TIMP2 as a key modulator of age-associated microglia dysfunction. Harnessing its activity may mitigate detrimental effects of age-associated insults on microglia function.

Female reproductive aging is a complex process with profound systemic health implications, yet the molecular and structural dynamics of aging across reproductive organs and tissues remain largely unexplored. Here, we integrate deep learning-based analysis of 1,112 histological images with RNA-seq data from 659 samples across seven reproductive organs in 304 female donors aged 20-70 years. We show that female reproductive organs and tissues have asynchronous aging dynamics: while the ovary and vagina age gradually, the uterus undergoes an abrupt transcriptional and cellular transition around the age of menopause. Tissue segmentation highlights that the myometrium in the uterine wall is the most age-affected tissue, marked by extracellular matrix remodeling and immune activation. Across reproductive organs, the epithelial tissue is also strongly affected by age, with the vaginal epithelium showing a unique sharp menopausal transition. Integration via multi-omics factor analysis links these tissue-specific histological transformations to specific molecular shifts, many with nonlinear expression trajectories and enriched in heritable reproductive traits such as pelvic organ prolapse and age at menarche. These findings position menopause as a key inflection point in female aging and provide insights with tissue-specific focus to support healthier menopausal transitions and reduce age-related disease risk.

Immunosenescence is the loss and change of immunological organs, as well as innate and adaptive immune dysfunction with ageing, which can lead to increased sensitivity to infections, age-related diseases, and cancer. Emerging evidence highlights the role of gut-vitamin D axis in the regulation of immune ageing, influencing chronic inflammation and systemic health. This review aims to explore the interplay between the gut microbiota and vitamin D in mitigating immunosenescence and preventing against chronic inflammation and age-related diseases.

Aging varies across individuals, highlighting the need for better markers of functional decline. This study investigates the hypothesis that T cell energy metabolism is correlated with functional health in older adults. We used flow cytometry-based profiling to examine energy metabolism, focusing on mitochondrial OXPHOS activity (MitoDep, expressed as percentage), in peripheral CD4 and CD8 T cell subsets from 187 participants aged 70-89 years (mean age 78.7 [SD 5.3], 57.7% [n = 108] women) within the Inspire-T cohort. Associations with Fried frailty phenotype were evaluated, using logistic regression. Relationships with intrinsic capacity (IC) score were assessed using partial least square regression (PLS) and piecewise linear regression models, adjusting for age, sex and comorbidities. MitoDep was significantly lower in prefrail/frail individuals (47% of the study population) across several T cells subsets. In CD4 regulatory T cell (CD4Treg) subsets, higher MitoDep was significantly associated with reduced odds of prefrailty/frailty. Piecewise regression identified a breakpoint in memory CD4Treg MitoDep at 58.5% (95% CI, 50.7-67.5). Below this threshold, reduced MitoDep was significantly associated with lower IC (β = 0.40, p = 0.0104). This study establishes a novel link between T cell mitochondrial OXPHOS activity and functional health in older adults, offering insights for improved patient stratification and personalized lifestyle or therapeutic interventions.

With increased age, the liver becomes more vulnerable to metabolic dysfunction-associated steatohepatitis (MASH) with fibrosis. Deciphering the complex interplay between aging, the emergence of senescent cells in the liver and MASH fibrosis is critical for developing treatments. Here we report an epigenetic mechanism that links liver aging to MASH fibrosis. We find that upregulation of the chromatin remodeler BAZ2B in a subpopulation of hepatocytes (HEPs) is linked to MASH pathology in patients. Genetic ablation or hepatocyte-specific knockdown of Baz2b in mice attenuates HEP senescence and MASH fibrosis by preserving peroxisome proliferator-activated receptor α (PPARα)-mediated lipid metabolism, which was impaired in both naturally aged and MASH mouse livers. Mechanistically, Baz2b downregulates the expression of genes related to the PPARα signaling pathway by directly binding their promoter regions and reducing chromatin accessibility. Thus, our study unravels the BAZ2B-PPARα-lipid metabolism axis as a link from liver aging to MASH fibrosis, suggesting that BAZ2B is a potential therapeutic target for HEP senescence and fibrosis.

Complex diseases often exhibit sex-dimorphism in morbidity and prognosis, many of which are age-related. However, the underlying mechanisms of sex-dimorphic aging remain foggy, with limited studies across multiple tissues. We systematically analyzed ~17,000 transcriptomes from 35 human tissues to quantitatively evaluate the individual and combined contributions of sex and age to transcriptomic variations. We discovered extensive sex-dimorphisms during aging with distinct patterns of change in gene expression and alternative splicing (AS). Intriguingly, the male-biased age-associated AS events have a stronger association with Alzheimer's disease, and the female-biased events are often regulated by several sex-biased splicing factors that may be controlled by estrogen receptors. Breakpoint analysis showed that sex-dimorphic aging rates are significantly associated with decline of sex hormones, with males having a larger and earlier transcriptome change. Collectively, this study uncovered an essential role of sex during aging at the molecular and multi-tissue levels, providing insight into sex-dimorphic regulatory patterns.

Background: Changes to the epigenetic landscape play an important role in cardiovascular aging, where alterations in histone modifications influence gene expression by regulating DNA accessibility and chromatin structure. Our investigation into epigenetic changes during myocardial aging revealed that the repressive epigenetic mark H3K27me3 is significantly upregulated in aged mice and humans. This increase in H3K27me3 was shown to impair cardiomyocyte autophagy and drive metabolic reprogramming, key features of myocardial aging and causatively linked to dysfunction. Notably, by alleviating this repressive mark through a modified diet, we successfully mitigated the aged myocardial phenotype. Methods: Heart tissue from young and aged mice and humans was analyzed for H3K27me3 levels using immunoblotting and immunofluorescence staining. Genes regulated by H3K27me3 were identified through CUT&RUN-Seq and RNA-Seq, while metabolites were profiled using metabolomics. In neonatal rat ventricular myocytes (NRVMs), H3K27me3 levels were elevated by siRNA-mediated knockdown of UTX. Cellular metabolism was investigated using a Seahorse analyzer in cardiomyocytes with basal or elevated H3K27me3 levels. In further human studies, we assessed how circulating glutamine levels associate with the incidence of heart failure and the association of genetic variants within the SLC1A5 region with heart disease. In aged mice, H3K27me3 levels were reduced through a modified diet, and heart function was evaluated using echocardiography. Subsequently, hearts were processed for biochemical analysis, and autophagy was assessed using electron microscopy Results: H3K27me3 was significantly elevated in the aged mouse and human myocardium. This observed elevation in H3K27me3 was found to be attributed to impaired glutamine metabolism, resulting from reduced expression of the glutamine transporter SLC1A5 in the aged myocardium. Furthermore, elevation in H3K27me3 was found to contribute to impaired cardiomyocyte autophagy and metabolic dysfunction. In aged mice supplemented with a high glutamine diet this attenuated myocardial H3K27me3 and improved cardiac function. Furthermore, a high-glutamine diet reversed H3K27me3-mediated impairment in cardiac autophagy in aged mice. Conclusions: Reduction in SLC1A5 during aging is likely to lead to increased myocardial H3K27me3 that results in impaired autophagy and metabolic reprogramming that contribute to the aged cardiac phenotype. Our findings also suggest glutamine may improve cardiac health in the aged population by lowering H3K27me3.

Cognitive decline associated with healthy ageing is complex and multifactorial: brain based and lifestyle factors uniquely and jointly contribute to distinct neurocognitive trajectories of ageing. To evaluate existing models of neurocognitive ageing such as compensation, maintenance, or reserve, we explore how various known brain-based and cardiorespiratory fitness factors intersect to better understand cognitive decline. In a preregistered study (https://osf.io/6fqg7), we tested 73 neurologically healthy older adults aged 60 to 81 (M = 65.51, SD = 4.94, 49% female) and collected neuroimaging (functional, structural, and perfusion MRI), cardiorespiratory fitness, and behavioural performance data to investigate a well-documented, prominent cognitive challenge for older adults: word-finding failures. Blood-oxygen level-dependent (BOLD) fMRI signal was recorded while participants responded to a definition-based tip-of-the-tongue task, high-resolution T1-weighted imaging was employed to estimate grey matter volume, and perfusion (or cerebral blood flow) was indexed using a multi-delay pseudocontinuous arterial spin labelling approach. Commonality analyses were used to analyse the multi-domain data (neuroimaging, cardiorespiratory fitness, language skills, demographic characteristics). We aimed to uncover associations between predictors, which have previously been theoretically-implicated, in explaining age-related tip-of-the-tongue rates. Commonality analyses revealed that functional activation of language networks associated with tip-of-the-tongue states is in part linked with age and, interestingly, cardiorespiratory fitness levels. Age-associated atrophy and perfusion in regions other than those showing functional differences accounted for variance in tip-of-the-tongue states. Our findings can be interpreted in the context of the classic models of neurocognitive ageing suggesting compensation. Brain health indices in concordance with cardiorespiratory fitness measures have the potential to provide a more holistic explanation of individual differences in age-related cognitive decline.

Tissue inhibitor of metalloproteinases 3 (TIMP-3) is a critical regulator of extracellular matrix turnover. Mutations in TIMP-3 cause Sorsby fundus dystrophy, an inherited macular dystrophy that is similar to age-related macular degeneration (AMD), but which generally presents earlier. SFD is characterised by the accumulation of mutant TIMP-3 protein in Bruch\'s membrane, a multilamellar extracellular matrix underlying the retinal pigment epithelium (RPE). Here, we show that RPE cells regulate wild-type TIMP-3 levels post-translationally, with ARPE-19 and hTERT RPE-1 cells endocytosing the protein via the low-density lipoprotein receptor-related protein (LRP) family of scavenger receptors. LRP-mediated endocytosis of the SFD TIMP-3 variants S204C and Y191C was significantly delayed, establishing a molecular mechanism for their extracellular accumulation in SFD. In contrast, endocytosis of the SFD variant H181R TIMP-3 was unaltered, suggesting it accumulates through a distinct molecular mechanism, potentially via increased retention on extracellular matrix heparan sulfate proteoglycans. These findings reveal heterogeneity in the molecular mechanism of SFD pathogenesis, which has direct implications for therapeutic development. Genotype-specific interventions may be required, such as strategies to enhance receptor-mediated clearance or disrupt extracellular TIMP-3 retention. Our study also has broader implications for AMD, where TIMP-3 and other LRP and heparan sulfate ligands accumulate in drusen within Bruch\'s membrane. Age- and inflammation-dependent alterations in LRP expression and heparan sulfate structure may contribute to drusen formation and AMD progression. Understanding TIMP-3 trafficking in both physiological and pathological contexts could inform targeted treatments for SFD, AMD, and other degenerative disorders involving extracellular matrix dysregulation.