Longevity Papers

Aging, the key risk factor for cognitive decline, impacts the brain in a region-specific manner, with microglia among the most affected cell types. However, it remains unclear whether this is intrinsically mediated or driven by age-related changes in neighboring cells. Here, we describe a scalable, genetically modifiable system for in vivo heterochronic myeloid cell replacement. We find reconstituted myeloid cells adopt region-specific transcriptional, morphological and tiling profiles characteristic of resident microglia. Young donor cells in aged brains rapidly acquired aging phenotypes, particularly in the cerebellum, while old cells in young brains adopted youthful profiles. We identified STAT1-mediated signaling as one axis controlling microglia aging, as STAT1-loss prevented aging trajectories in reconstituted cells. Spatial transcriptomics combined with cell ablation models identified rare natural killer cells as necessary drivers of interferon signaling in aged microglia. These findings establish the local environment, rather than cell-autonomous programming, as a primary driver of microglia aging phenotypes.

Healthy aging is accompanied by a gradual decline in higher-order cognitive functions, including working memory, attention, and cognitive flexibility, processes that critically rely on intact frontal cortical circuits. While neuronal loss is minimal during aging, whether there are changes in functional plasticity in this region remains unexplored. In this regard, dendritic spines, the primary postsynaptic structures of excitatory synapses, act as key hubs for experience-dependent synaptic remodeling. Using longitudinal in vivo two-photon imaging in Thy1-eGFP-M mice, we examined age-related changes in dendritic spine density and dynamics in layer 5 pyramidal neurons of the secondary motor area (MOs), a frontal cortical region essential for strategy switching and cognitive flexibility, and that was assessed using an operant conditioning paradigm. We found that aged mice (18 to 22 months) exhibited significant impairments in cognitive flexibility relative to young mice (3 to 5 months) in the four-odor choice discrimination and reversal task. Analysis of dendritic spine plasticity revealed that baseline spine density, turnover, and morphology were largely preserved in aged mice. Sex differences were evident, with females displaying higher spine density and a greater fraction of stable spines, a feature maintained across aging. Importantly, despite preserved baseline architecture, aged mice showed impaired ketamine-induced spinogenesis and reduced stabilization of newly formed spines, in contrast to the robust structural plasticity observed in young mice. These results indicate that healthy aging selectively impairs activity-dependent synaptic remodeling without affecting steady-state spine architecture in frontal cortical circuits. By linking deficits in induced synaptic plasticity to age-related impairments in cognitive flexibility, our study highlights the critical need to target plasticity mechanisms as a therapeutic strategy to restore executive function and cognitive adaptability in the aging brain.

The relationship between vestibular function and white matter (WM) integrity is poorly understood, despite increasing evidence linking vestibular sensory decline and motor and cognitive deficits in older adults. This study examined associations between vestibular function and the microstructural integrity of 19 WM pathways in 394 cognitively healthy participants aged 60+ from the Baltimore Longitudinal Study of Aging who had regional WM microstructure assessed by diffusion tensor imaging metrics: fractional anisotropy and mean diffusivity. The vestibular functions of the saccule, utricle, and horizontal semi-circular canal were assessed using the cVEMP and oVEMP tests and the vHIT, respectively. Multiple linear regression of WM metrics onto vestibular function, adjusted for age, sex, intracranial volume, and scanner type, was used to examine the association between WM and vestibular function. We found that higher canal function was associated with higher integrity in the external capsule, the cingulum projection to the hippocampus, the inferior fronto-occipital fasciculus, and the genu of the corpus callosum, but lower integrity in the limbs of the internal capsule, sagittal stratum, posterior thalamic radiation, the cingulum projection to the cingulate gyrus, and fornix. Utricular function was associated with higher integrity in the anterior limb of the internal capsule and the fornix but lower integrity in the retrolenticular limb of the internal capsule. Saccular function was not associated with WM microstructure. This study demonstrates for the first time potential associations between vestibular end-organ function and WM microstructure in healthy, older adults, with horizontal canal function exhibiting diffuse associations with multi-sensorimotor tracts, whereas utricular function shows more focal associations. Because these findings are concomitant with lower age-related WM integrity, they suggest that better vestibular function may confer resilience in certain pathways while potentially accelerating age-related degeneration in others. Longitudinal studies will be needed to robustly identify WM neuroimaging markers of aging-associated vestibular loss over time.

Small humanin-like peptide-6 (SHLP6), is derived from the mitochondrial genome. The 3D structure of SHLP6 was evaluated using PEPstr, with homology modeling predicting a Cyt-C structure with a DOPE score of -645.717 and a GA341 score of 0.2832. The analysis showed that 96.5 % of residues were in favored regions in the Ramachandran plot, indicating a stable protein conformation. Molecular docking studies revealed that SHLP6 has binding affinities with apoptotic proteins such as Caspase 8 (-77.6 ± 2.9 kcal/mol), Bcl-2 (39.2 ± 15.3 kcal/mol), Bax (43.6 ± 7.7 kcal/mol), Cyt-C (-53.2 ± 8.7 kcal/mol), and CAT (-62.5 ± 1.3 kcal/mol). The interaction of SHLP6 with DRP1 (-47.7 ± 1.9 kcal/mol) was found to promote apoptosis, while interactions with SIRT1 (-49.1 ± 4.7 kcal/mol), IGF-1 (-58.7 ± 3.6 kcal/mol), and INSR (-66.4 ± 3.4 kcal/mol) suggest a potential role in controlling neurodegeneration. Molecular dynamics simulations confirmed the compact conformation of Caspase-8, high structural stability of SIRT1, and flexibility of DRP1. Treatment with SHLP6 (40 μg/ml) reduced developmental toxicity and improved antioxidant enzyme levels (SOD and CAT) in stress-induced zebrafish larvae. SHLP6 treatment also improved AChE levels in H

Age-related eye diseases (AREDs) are the leading cause of visual impairment in the elderly, affecting the structure of the anterior and posterior segments of the eye, significantly reducing the quality of life of patients, and even leading to irreversible blindness. Typical AREDs include age-related cataract (ARC), dry eye disease (DED), age-related macular degeneration (AMD), glaucoma, and diabetic retinopathy (DR), the global prevalence of which continues to rise, becoming a serious public health concern. SIRT1 is an NAD + dependent deacetylase, which plays an important physiological regulatory role in ocular tissues, mainly affecting gene expression and various cellular processes by regulating the acetylation status of substrate proteins. Studies have shown that SIRT1 plays a key role in oxidative stress, inflammation, autophagy, apoptosis and metabolism, and its expression or activity decreases can accelerate cell senescence and promote the occurrence and development of AREDs. In addition, SIRT1 expression levels and changes in its activity have been shown to be strongly associated with AREDs, making it a potential target for disease intervention and therapy. Therefore, this review systematically summarizes the biological role and regulatory mechanism of SIRT1 in AREDs, and explored its potential value as a therapeutic target, providing theoretical basis for future drug development and clinical transformation.

Aging is the main risk factor for Parkinson's disease (PD), yet our understanding of how age-related mechanisms contribute to PD pathophysiology remains limited. We conducted a longitudinal analysis of blood samples from the Parkinson's Progression Markers Initiative cohort to investigate DNA damage in PD. Patients with PD exhibited disrupted DNA repair pathways and biased suppression of longer transcripts, indicating age-related, transcription-stalling DNA damage. Notably, at the intake visit, this DNA damage signature was detected only in patients with more severe progression of motor symptoms over 3 years, suggesting its potential as a predictor of disease severity. We validated this signature in independent PD cohorts and confirmed increased DNA damage in peripheral blood cells and dopamine neurons of the substantia nigra pars compacta in postmortem PD brains. Our study sheds light on an aging-related mechanism in PD pathogenesis and identifies potential markers of disease progression, providing a diagnostic platform to prognosticate disease progression.

Protein aggregation in various cellular compartments is a hallmark of proteostasis impairment linked to aging and numerous pathologies. Mitochondrial function depends on a balanced interplay of proteins imported from the cytosol as well as those synthesized on mitochondrial ribosomes (mitoribosomes). Here, we reveal an unexpected susceptibility of mitoribosome biogenesis to organellar proteostatic stress. Importing aggregation-prone proteins into yeast and human mitochondria triggered a chain of detrimental events involving extensive co-aggregation of newly-imported mitoribosome subunits and other RNA-binding proteins, as well as local disruption of mitochondrial cristae morphology. As a result, mitoribosome assembly and mitochondrial translation were severely impaired, leading to respiratory deficiency and, ultimately, loss of mitochondrial DNA. Surprisingly, dysfunction of mitochondrial HSP60 phenocopied the ribosome biogenesis defect and inhibition of translation, indicating a pronounced chaperone dependence of mitoribosome proteins. Declining mitochondrial translation likely contributes to aging and diseases associated with deficiencies in mitochondrial protein quality control machinery.

The fundamental cause theory posits social factors as causes of disease as they encompass access to important resources such as knowledge, wealth, and social networks. While these social factors have been consistently associated with oral and systemic diseases, causality remains unestablished. Here, we estimated the causal effect of social adversity, comprising low economic and social capital, on the development of (1) oral conditions (OC) and (2) multimorbidity including oral conditions (MIOC) in a cohort of middle-aged and older adults over a 7-y period and assessed whether effects varied by age or gender. We analyzed 2 waves from the Canadian Longitudinal Study on Aging (CLSA) (2011 and 2018). Social adversity comprised low economic (income) and social capital (community participation, social relationships). OC was defined as having 1 or more of poor self-reported oral health, lack of functional dentition (<20 natural teeth), or edentulism. Participants with an OC at baseline were excluded. MIOC was defined as having 2 or more chronic diseases and an OC. Logistic marginal structural models with inverse probability weighting estimated the causal odds ratio (OR) of developing both outcomes, controlling for sociodemographic and behavioral factors. In a total of 23,366 participants, 14% experienced social adversity at baseline, with a prevalence of 17% OC and 7% MIOC at follow-up. Social adversity significantly increased the odds of developing OC (OR = 1.9, 95% confidence interval [CI] 1.7, 2.2) and MIOC (OR = 1.7, 95% CI 1.5, 2.0) at follow-up. The observed effects were strongest in the middle-aged group, with similar odds observed in both men and women. Our findings indicate that social and economic capital are causally linked to the development of OC and MIOC over time. We suggest that policies for healthy aging should prioritize action on social and living conditions.

The physiological decline associated with aging is often accompanied by a progressive deterioration in cognitive processing abilities driven by a series of cellular dysfunctions that remain poorly understood. In the hippocampus, a critical area for learning and memory, aging affects the functional expression of ionotropic and metabotropic receptors, including the metabotropic glutamate receptors (mGluRs). mGluRs play a critical role in multiple cellular functions, including modulation of ion channels and intrinsic excitability, synaptic transmission, and induction of synaptic plasticity, processes considered part of the cellular substrates for learning and memory. This study used patch-clamp recordings and pharmacological tools in acute hippocampal slices to uncover the aging-related disruption in the mGluR-dependent modulation of area CA3 pyramidal neurons. Pharmacological stimulation of group I mGluRs triggers rhythmic firing discharge in CA3 pyramidal neurons of young rats (5 ± 1 weeks of age) and a reduction in the afterhyperpolarization. By contrast, in older adult rats (20-24 months of age), stimulation of group I mGluRs causes a switch from afterhyperpolarization to an afterdepolarization plateau that eases a persistent but non-rhythmic firing discharge. In young animals, postsynaptic activation of group II mGluRs enhances the intrinsic excitability of CA3 pyramidal neurons, and an exacerbated response is observed in older adult rats. By contrast, in older adult animals, the presynaptic inhibition of glutamate release by pharmacological stimulation of group II mGluRs from mossy fibers was significantly reduced. These findings support the notion of older adult-related changes in the functional expression of mGluRs within the hippocampal area CA3 that may contribute to the cognitive alterations commonly associated with aging.

Vascular aging contributes to multisystem diseases and limits health span. Although various animal models have contributed to aging research, their vasculatures poorly recapitulate human physiology. Even existing tissue-engineered blood vessels fail to mimic human vascular function and pathology, hindering translational advances in vascular aging studies. Here, we present a novel human physiological vascular model fabricated via the unique molding-induced circumferential alignment of human induced pluripotent stem cell (iPSC)-derived vascular smooth muscle cells with luminally seeded endothelial cells. This architecture enabled dynamic vasodiameter changes in response to vasoactive stimuli, including hormones and intraluminal pressure. Using iPSCs from a patient with Werner syndrome, the model recapitulated aging-associated phenotypes, such as hypercontractility and increased vascular compliance, possibly due to impaired nitric oxide bioavailability. Transcriptomic and metabolomic analyses revealed age-related dysregulation consistent with vascular senescence. As a key advantage of the vasculature, spatial transcriptomic analysis demonstrated upregulation of the aging marker CDKN1A near the lumen and downregulation of COL6A1 and TPM1 throughout the vessel. Treatment with mitochonic acid 5, a mitochondria-targeted compound, significantly reversed the aging phenotypes. These findings demonstrate that our engineered vascular model recapitulates key aspects of human vascular properties and provides a platform for mechanistic studies of vascular aging and drug discovery aimed at extending health span.

Cellular senescence is a critical factor in organismal aging and age-related diseases. Nicotinamide adenine dinucleotide (NAD

Intestinal immunosenescence, a hallmark of organismal aging, has emerged as a critical biological process impacting the health of elderly individuals. This review systematically examines the core mechanisms underlying intestinal immunosenescence, including immune cell dysfunction, imbalances in immune-microbiota interactions, and impaired barrier function. We analyze its associations with infectious diseases, chronic inflammation, and neurodegenerative disorders, summarizing recent advances in dietary interventions, microecological therapy, and other emerging strategies. By integrating cutting-edge technologies, we prospect the development of precision interventions aimed at delaying intestinal immunosenescence, thereby providing a theoretical basis for improving the healthspan of the aging population.

Mitochondria are the regulators of energy production and play a vital role in modulating ageing and age-associated diseases. We investigated the role of sirtuins, a well-studied class of longevity-associated proteins (NAD+-dependent histone deacetylases), in mitochondrial biology and Parkinson's disease pathology. In particular, we endeavored to study the functional implications of mitochondrial sirtuin, sir-2.2 (ortholog of human SIRT4), in regulating neuroprotection employing Caenorhabditis elegans model. We observed that upon sir-2.2 knockdown, the alpha-synuclein aggregation was increased and expression of dopamine transporter, dat-1, was reduced. Also, the levels of marker proteins for innate immunity, oxidative stress, mitophagy, UPRmt, and autophagy, were decreased, suggesting an important function of sir-2.2 in maintaining mitochondrial homeostasis, regulating protein clearance and ameliorating the disease condition. Because of their crucial role in regulating oxidative stress and mitochondrial quality control, studying mitochondrial sirtuin will provide therapeutic insights into the metabolic regulation of ageing and neurodegeneration.

Ferroptosis has been implicated in skeletal muscle aging. Nevertheless, specific ferroptosis-related genes (FRGs) governing skeletal muscle aging remain unclear. The aim of this study was to identify ferroptosis-related marker genes associated with skeletal muscle aging, uncovering potential therapeutic targets for skeletal muscle aging. Data from GSE38718 was utilized to identify differentially expressed FRGs (DE-FRGs) in aging versus normal human skeletal muscle by the least absolute shrinkage and selection operator (LASSO) and the support vector machine recursive feature elimination (SVM-RFE) algorithms. Validation was conducted using RT-qPCR and Western blot in aging mouse muscle and D-galactose (D-gal)-treated C2C12 cells. SLC38A1 was identified as a significantly downregulated marker for aging skeletal muscle. Overexpression of SLC38A1 mitigated cellular aging in D-gal treated C2C12 cells. In both D-gal treated and sh-SLC38A1 C2C12 cells, increased ROS levels, elevated mtROS, higher intracellular iron concentrations, and intensified lipid peroxidation were observed. In contrast, SLC38A1 overexpression markedly reduced the accumulation of ROS, mtROS, iron concentration, and lipid peroxidation associated with D-gal treatment in these cells. In conclusion, through screening analyses and validation experiments, we identified SLC38A1 as a ferroptosis-related regulator for skeletal muscle aging.

Curiosity enhances learning and memory and has been linked to the locus coeruleus (LC), which undergoes age-related decline. To examine how aging affects curiosity and information-seeking, we developed the Photographic Art Storytelling Task. Participants (sixty-eight young and sixty-five older adults) viewed photographs, rated their curiosity, and later read stories associated with selected images. The stories were deliberately constructed to be either interesting or boring, functioning as rewards that elicited prediction errors. Participants reappraised their curiosity, allowing us to separate intrinsic motivation from story-driven reward influences. Associations between performance and both pupil diameter and MRI measures of LC integrity supported a role of LC in curiosity regulation. Aging was associated with greater reliance on novelty-driven (initial) curiosity and a shift away from prediction error-related information-seeking. Both age groups showed curiosity-driven memory enhancement, with older adults exhibiting youth-like effects, suggesting a role for intrinsic motivation in preserving cognitive function in aging.

Dietary restriction (DR), which slows aging, increases the ratio of reduced glutathione (GSH) to oxidized glutathione disulfide (GSSG) in the brain. DR increases liver cytoplasmic [NADPH]/[NADP

Aging is associated with progressive declines in skeletal muscle mass, strength, and endurance, often linked to mitochondrial dysfunction. However, a complete understanding of mitochondrial impairments during aging is lacking. Herein, we examined how biological sex and aging affect muscle function and mitochondrial energy transduction.

The accumulation of senescent cells (SNCs) contributes to tissue dysfunction and age-related diseases, creating an urgent need for effective senolytic strategies. We identified a metabolic vulnerability in SNCs characterized by marked downregulation of asparagine synthetase (ASNS), rendering them uniquely dependent on exogenous asparagine (Asn). This vulnerability was exploited through combined treatment with L-asparaginase (ASNase) and autophagy inhibitors, which synergistically deplete Asn via complementary mechanisms: ASNase degrades extracellular Asn pools, while autophagy inhibition blocks intracellular protein recycling as an alternative Asn source. This dual approach induced selective synthetic lethality across multiple SNC types in vitro. In aged mice, the combination therapy significantly reduced SNC burden in diverse tissues, improved physiological function, and attenuated progression of age-related conditions including osteoporosis, atherosclerosis, and non-alcoholic fatty liver disease. Our findings establish concurrent targeting of extracellular and intracellular Asn supplies as a potent, selective senolytic strategy with broad therapeutic potential for age-related disorders.

Smoking is one of the single most important preventable risk factors for cancer and other adverse health outcomes [1,2]. Smoking cessation represents a key public health intervention with the potential to reduce its negative health outcomes [2-4]. While epidemiological, cross-sectional, and individual longitudinal \'omic\' or biomarker studies have evaluated the impact of smoking cessation, no study to date has systematically profiled molecular and clinical changes in several organ systems or tissues longitudinally over the course of smoking cessation that could allow for more detailed assessment of response biomarkers and the identification of interindividual differences in the recovery of physiological functions. Here, we report the first human longitudinal multi-omic study of smoking cessation, evaluating 2,501 unique single or composite features from 1,094 longitudinal samples. Our comprehensive analysis, leveraging over half a million longitudinal data points, revealed a profound effect of smoking cessation on epigenetic biomarkers and microbiome features across multiple organ systems within 6 months of smoking cessation, alongside shifts in the immune and blood oxygenation system. Moreover, our multi-omic analysis provided unprecedented granularity that allows for identification of new cross-ome associations for mechanistic discovery. We anticipate that data and an interactive app from the Tyrol Lifestyle Atlas (eutops.github.io/lifestyle-atlas), comprising the current study and a parallel study arm evaluating the impact of diet on biomarkers of health and disease, will provide the basis for future discovery, biomarker benchmarking in their responsiveness to health-promoting interventions, and study of individualised response group, representing a major advance for personalised health monitoring using biomarkers.

While intermittent fasting (IF) promotes longevity in animal models, its systemic effects in humans remain poorly understood. Here, we present a six-month longitudinal IF intervention in 114 women (BMI 25-35) with deep clinical, molecular, and microbiome profiling across >3,400 biospecimens from six tissues. Analyses spanning >2,200 multi-omic features and 11,000 microbial function predictions demonstrate coordinated clinical benefits, including improvements in body composition and cardiorespiratory fitness, and reveal coordinated molecular responses across tissues. Iron metabolism emerged as a central axis: transferrin increased while ferritin, haemoglobin, and erythrocytes decreased, changes that opposed ageing trajectories yet remained within physiological limits. Epithelial DNA methylation biomarkers (cervical, buccal) of cancer risk reduced, while blood clocks were largely unresponsive, underscoring tissue-specificity of the epigenome. Immune profiling uncovered dynamic, partially reversible shifts. Notably, we derived a new immunophenotyping-based ImmuneAge score that increased during fasting and tracked with inflammatory function, while the pro-inflammatory cytokine IL-17A declined selectively in postmenopausal women. Oral microbiota showed rapid restructuring, whereas gut microbiota shifted more subtly toward enhanced metabolic capacity. Together, these data provide unprecedented insight into the systemic and tissue-specific responses to IF in humans and identify iron homeostasis and immune remodelling as candidate mechanisms. Our findings are available through the Lifestyle Atlas (https://eutops.github.io/lifestyle-atlas).

Accurate detection of somatic mutations in noncancerous cells is critical for studying somatic mosaicism, a process implicated in aging and multiple chronic diseases. However, single-cell and single-molecule DNA sequencing platforms differ in their error profiles, coverage biases, and sensitivity to specific mutation types, complicating cross-platform comparisons. Here, we present in vitro and in silico benchmarks to quantify true-positive and false-positive rates in single-cell whole-genome sequencing using Single-Cell Multiple Displacement Amplification, and in single-molecule sequencing using Nanorate Sequencing (NS) and whole-genome NS (WGNS). Using standard cell lines, we show that all three methods detect single-nucleotide variants (sSNVs) and small insertions and deletions (sINDELs) with high accuracy, but differ in genomic coverage and susceptibility to artifacts. Method-specific biases influence mutational signatures and hotspot detection. Applying results of the benchmark to IMR-90 fibroblasts, we estimate higher in vitro mutation rates using NS than expected from in vivo data, consistent with potential replication stress and culture-associated DNA damage. Overall, our study highlights the substantial impact of sequencing platform-specific biases on somatic mutation detection and interpretation, and lays the foundation for standardized, cross-platform-comparable analyses of somatic mosaicism in normal human tissues.

Aging of the blood system impacts systemic health and can be traced to hematopoietic stem cells (HSCs). Despite multiple reports on human HSC aging, a unified map detailing their molecular age-related changes is lacking. We developed a consensus map of gene expression in HSCs by integrating seven single-cell datasets. This map revealed previously unappreciated heterogeneity within the HSC population. It also links inflammatory pathway activation (TNF/NF{kappa}B, AP-1) and quiescence within a single gene expression program. This program dominates an inflammatory HSC subpopulation that increases with age, highlighting a potential target for further experimental studies and anti-aging interventions.

Vascular aging increases the susceptibility to cardio-cerebrovascular conditions, such as atherosclerotic diseases and hypertension, the leading causes of global disability and mortality. Dietary citrate extends the lifespan of Drosophila melanogaster and Caenorhabditis elegans as well as improves the memory of mice injured by a high-fat diet (HFD); whether it alleviates vascular aging and age-related vascular diseases; however, remains unknown. Here, we showed that dietary supplementation of citrate delayed vascular aging, as evidenced by maintaining the integrity of elastic fibers and decreasing the level of the aging-related marker, CDKN1A (p21). Functionally, citrate improved the sensitivity to endothelial-dependent vasodilators and lowered blood pressure, and in HFD-fed ApoE

Human and murine studies reveal that innate immune cells are able to mount enhanced responses to pathogens after primary inflammatory exposure. Innate immune memory has been shown to last for months to years, longer than the lifespan of most innate immune cells. Indeed, long-lived hematopoietic stem and progenitor cells (HSPCs) serve as a cellular reservoir for innate immune memory. In this review, we summarize the evidence that innate immune memory is epigenetically encoded in HSPCs, and we consider whether HSPC subpopulations with differentiation bias, cell autonomous epigenetic reprogramming, or both features underlie the phenomenon of central trained immunity. We further profile the significant implications of central trained immunity in stem cell transplant, aging, inflammatory diseases, and vaccination strategies for the future.

Dietary protein is a key regulator of metabolic health in humans and rodents. Many of the benefits of protein restriction are mediated by reduced consumption of dietary branched-chain amino acids (BCAAs; leucine, valine and isoleucine), and restriction of the BCAAs is sufficient to extend healthspan and lifespan in mice. While the BCAAs have often been considered as a group, it has become apparent that they have distinct metabolic roles, and we recently found that restriction of isoleucine is sufficient to extend the healthspan and lifespan of male and female mice. Here, we test the effect of lifelong restriction of the BCAA valine on healthy aging. We find that valine restriction (Val-R) improves metabolic health in C57BL/6J mice, promoting leanness and glycemic control in both sexes. To investigate the molecular mechanisms engaged by Val-R with aging, we conducted multi-tissue transcriptional profiling and gene network analysis. While Val-R had a significantly greater molecular impact in the liver, muscle, and brown adipose tissue of female mice than males, there was a stronger gene enrichment with phenotypic traits in male mice. Further, we found that phenotypic changes are associated with a multi-tissue downregulation of the longevity associated PI3K-Akt signaling pathway. Val-R reduces frailty in both sexes and extends the lifespan of male by 23%, but does not extend female lifespan, corresponding with a male-specific downregulation of PI3K-Akt signaling. Our results demonstrate that Val-R improves multiple aspects of healthspan in mice of both sexes and extends lifespan in males, suggests that interventions that mimic Val-R may have translational potential for aging and age-related diseases.

Epigenetic clocks are measures of biological aging related to critical health outcomes, including mortality. The present study examined whether personality traits are related to epigenetic aging. Participants (Age range: 17-98 years, N > 6000) were from the Health and Retirement Study, the Midlife in the United States study, and the UK Household Longitudinal Study. Measures of personality traits, demographic factors, first-generation (Hannum, Horvath), second-generation (PhenoAge, GrimAge), and third-generation (DunedinPoAM38/DunedinPace) epigenetic clocks were obtained in each sample. The strongest evidence emerged for conscientiousness: The meta-analysis indicated that higher conscientiousness was associated with a slower epigenetic aging as indexed by second- and third-generation clocks. The other traits were not consistently associated with the five clocks. Surprisingly, moderation by age indicated agreeableness was associated with slower epigenetic aging among relatively older but not younger adults. The present study suggests that conscientiousness is associated with slower epigenetic aging, particularly second and third-generation clocks trained on health-related outcomes.

The sustained production of blood and immune cells is driven by a pool of hematopoietic stem cells (HSCs) and their offspring. Due to the intrinsic heterogeneity of HSCs, the composition of emergent clones changes over time, leading to a reduced clonality in aging mice and humans. Theoretical analyses suggest that clonal conversion rates and clonal complexity depend not only on HSC heterogeneity, but also on additional stress conditions. These insights are particularly relevant in the context of stem cell transplantations, which still remain the only curative option for many hematologic diseases, increasingly considered viable for elderly individuals. However, age-related clonal changes post-transplantation are not well understood. To address this, we conducted a barcode-based assessment of clonality to investigate post-transplantation changes in both homo- and hetero-chronic settings, combined with low- and high-intensity pre-conditioned recipients. A robust and polyclonal engraftment was observed across all groups, but with distinct differences in barcode diversity. In particular, transplanted aged HSCs showed no changes in clonality, regardless of recipient age or pre-conditioning. Young HSCs transplanted into severely pre-conditioned old hosts as well as under reduced pre-conditioning, allowed for full lymphoid reconstitution, but showed substantial differences in clonality. Also, myeloid lineage bias, a hallmark of aged HSCs, was confirmed at a clonal level across all experimental groups. Overall, we found that aged HSCs generally maintain clonal diversity similar to young HSCs, but notable differences emerge under hetero-chronic conditions and varying pre-conditioning regimens. These findings challenge current paradigms and underscore the complex interactions between aging and transplantation conditions.

Research indicates a significant slowdown in life expectancy growth in the United States (US) post 2010, marking a departure from the consistent progress in longevity throughout the twentieth century. We extend this understanding, tracing the deceleration of US life expectancy back to the 1950s, after which average decadal change dropped from 3.80 to 1.61 years. Surprisingly, these mid-twentieth-century shifts were consistent across race and sex in the US and also in other high-income countries. Using a simple approach of quantifying potential life expectancy gains by eliminating mortality at specific ages, we find that the potential gains in life expectancy from reducing midlife mortality have been larger in the US than in other countries since 1900. The findings suggest that US life expectancy is unlikely to progress at the high speed observed between 1900 and the 1950s, with future advancements hinging on the reduction of old-age mortality, particularly from cardiovascular diseases and mental and nervous system diseases.

In recent years, an increasing number of researchers have become interested in the bidirectional communication between the gut microbiota and the central nervous system. This communication occurs through the microbiota-gut-brain axis. As people age, the composition of the gut microbiota undergoes considerable changes, which are now known to play an important role in the development of many neurodegenerative diseases. This review aims to investigate the complex bidirectional signaling pathways between the gut and the brain. It summarizes the latest research findings on how the gut microbiota and its metabolites play critical roles in regulating inflammation, maintaining gut health, and influencing the development of neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. The review also analyzes the current clinical applications of gut microbiota-based treatments for neurological disorders, including fecal microbiota transplantation, probiotics, and prebiotics. Many studies show that the gut microbiota affects the brain in several ways. For example, it can produce substances such as short-chain fatty acids and activate inflammatory pathways. Studies involving animals and laboratory models have demonstrated that adjusting the gut microbiota can help improve behavior and reduce neurological problems. Recent metagenomic and metabolomics studies have shown that the microbiota plays a crucial role in maintaining the organism's health. Microorganisms primarily colonize the gut and are involved in host nutrient metabolism, maintaining the structural integrity of the intestine, preserving the intestinal mucosal barrier, and modulating the immune system. The gut microbiota communicates with the brain through a bidirectional microbiota-gut-brain axis. The composition of the gut flora changes considerably with age, and ecological dysregulation has been recognized as one of the twelve most recent hallmarks of aging. Recent studies have linked these changes to a variety of age-related neurological disorders, including Alzheimer's disease, amyotrophic lateral sclerosis, Parkinson's disease, multiple sclerosis, and Huntington's disease. Specifically, the gut microbiota influences the brain through the production of key metabolites such as short-chain fatty acids and the activation of inflammatory and other relevant signaling pathways. In preclinical studies, targeted modulation of the gut microbiota, through methods such as fecal microbiota transplantation, probiotics, and prebiotics, has demonstrated potential in improving host behavioral outcomes. Therefore, gut microbiotabased treatments offer new hope for the treatment of nervous system diseases. However, due to the complexity of the gut microbiota and the potential adverse reactions associated with these therapies, researchers need to carefully assess their safety and efficacy before widespread clinical application.

Growth factors play a crucial role in regulating cellular processes such as proliferation, differentiation, and survival. Their activities are tightly modulated to ensure proper physiological functioning, with dysregulation often contributing to disease pathogenesis. Among these, the insulin-like growth factor (IGF) system that encompasses IGF-1 and IGF-receptor binding proteins is pivotal in maintaining overall cellular health by regulating growth, repair, and metabolic regulation. Capitalizing on its pro-mitogenic effects, translational studies have focused efforts on developing therapeutics based on IGF-1 for age-related muscle loss, metabolic disorders, or cardiovascular diseases. Mimetic peptide design has emerged as an innovative approach to overcoming limitations of direct IGF-1 therapy, focusing on structural optimization to enhance bioavailability, stability, and receptor specificity. Herein, the development of IGF-1 mimics and their potential clinical applications are reviewed. Their design and molecular properties, including structural considerations and mechanisms of action, are described. In vitro and in vivo approaches analyzed to provide insights into their pharmacokinetics, therapeutic efficacy, and safety profiles in animal models will be delved into. These preclinical studies shed light on the advantages of IGF-1 mimics, such as bioavailability, stability, and delivery, as well as the limitations, including potential immunogenicity.

With global population ageing, frailty poses a growing public-health challenge. Many countries have promoted social participation to mitigate frailty among older adults, but the cross-national consistency of this association remains unclear.

Systems biology offers valuable insights into aging by integrating experimental data with mathematical models and bioinformatics tools. Long-lived mutants of C. elegans, particularly clk-1, have provided extensive data on the aging mechanisms. The clk-1 gene, which encodes a ubiquitin precursor, shows a pleiotropic phenotype characterized by slow behavior, high mitochondrial ROS levels, autophagy, and metabolic changes. However, the link between these changes and lifespan extension remains unclear. Using a Boolean network, we modeled genetic interactions and derived differential equations for a continuous approach. Our results highlight that aak-2 (AMPK) is crucial for clk-1 lifespan extension owing to its role in stress response regulation. We introduced a health index based on the attrition of neuromuscular behaviors to assess the health of various strains. Our findings suggest that while stress responses may enhance lifespan, overall health is determined by the extent of the damage.

Despite the thousands of genes implicated in age-related phenotypes, effective interventions for aging remain elusive, a lack of advance rooted in the multifactorial nature of longevity and the functional interconnectedness of the molecular components implicated in aging. Here, we introduce a network medicine framework that integrates 2,358 longevity-associated genes onto the human interactome to identify existing drugs that can modulate aging processes. We find that genes associated with each hallmark of aging form a connected subgraph, or hallmark module, a discovery enabling us to measure the proximity of 6,442 clinically approved or experimental compounds to each hallmark. We then introduce a transcription-based metric, $pAGE$, which evaluates whether the drug-induced expression shifts reinforce or counteract known age-related expression changes. By integrating network proximity and $pAGE$, we identify multiple drug repurposing candidate that not only target specific hallmarks but act to reverse their aging-associated transcriptional changes. Our findings are interpretable, revealing for each drug the molecular mechanisms through which it modulates the hallmark, offering an experimentally falsifiable framework to leverage genomic discoveries to accelerate drug repurposing for longevity.

While aging impairs memory precision, its effects on engram dynamics and gene expression remain poorly understood. To address this, we used TRAP2 activity-reporter mice, nuclear tagging, and FOS-based activity mapping to track neurons activated during contextual fear memory encoding and reactivated during recall in young and aged mice. Across 378 brain regions, we quantified engram size, spatial distribution, and reactivation stability. We further applied fluorescence-activated nuclear sorting (FANS) combined with single-nucleus RNA sequencing (snRNA-seq) to characterize gene expression changes associated with memory encoding and recall across diverse cell types. In addition, we compared the transcriptional profiles of first-time versus second-time neuronal responder cells in the dentate gyrus. Aged brains exhibited altered engram allocation, reduced reactivation stability, and distinct gene expression patterns during memory retrieval. These findings reveal age-related changes in the organization and molecular identity of memory traces, providing mechanistic insight into cognitive decline and highlighting potential targets for intervention.

Research methods for the investigation of the biology of aging have often implicitly generalized strain-specific results. Dietary interventions, such as caloric restriction and periodic fasting, have been shown to enhance metabolic health and extend lifespan in preclinical models. However, inter-individual variation in physiological responses to these interventions, which affects their safety and efficacy when translated to humans, remains poorly understood despite being observed in multiple studies. In this study, we implemented intermittent fasting (IF) for two days per week in 10 inbred strains (n = 800 mice) from the Collaborative Cross (CC). The CC is a multiparent recombinant inbred strain panel that offers a diverse collection of reproducible models to study the genetic control of heterogeneous intervention responses. We conducted longitudinal phenotyping to characterize hundreds of traits, including lifespan, in the CC mice. We demonstrate that sex and genetic background induce variable responses to intermittent fasting across multiple physiological outcomes, including metabolic, hematologic, and immunologic health. Effects of IF on lifespan were sex-specific and variable across genetic backgrounds. Thus we establish that response to IF is genetically determined in an animal model with physiological features similar to humans. We compared our findings in the CC with those from a parallel study of Diversity Outbred (DO) mice, highlighting common predictors of health and lifespan, as well as key differences between the genetically diverse inbred and outbred models. These findings underscore the importance of genetic factors in dietary intervention responses, offering valuable insights for translating intermittent fasting benefits to human health and longevity.

Cancer risk increases with age, and cellular senescence may be a major contributor to cellular carcinogenesis. Enormous efforts have been made to investigate the interrelation between aging and tumors, but little is known about the comparative features of normal aging, cellular senescence, and cancer at single-cell resolution. By integrating analyses of genomics, epigenomics, and bulk and single-cell transcriptomics, we revealed a directionally opposite transcriptional profile between cellular senescence and tumorigenesis at the single-cell level, which may be affected by epigenomic regulations. A total of 648 aging-dependent senescence-associated coregulated modules (SACMs), disproportionately affecting the reproductive systems of both females and males, were initially defined across 17 tissues. Single-cell analysis revealed that aging primarily affects endothelial cells, followed by T cells, epithelial cells, macrophages, and fibroblasts. Opposite directions of change in gene expression between aging and cancer can commonly be observed in endothelial, fibroblast, and epithelial cells, which may prompt the opposing patterns of gene expression between tissue aging and epithelial carcinoma at the bulk level. A similar pattern of expression can be observed in immune cells, which are characterized by decreased self-renewal with aging, but this pattern is reversed in epithelial carcinoma. Our study highlighted the role of senescence as a natural barrier against tumor formation and supported the idea that aging-related systemic environment changes create a protumorigenic milieu.

Overexpression of the mRNA binding protein Ssd1 extends the yeast replicative lifespan. Using microfluidics to trap and image single cells throughout their lifespans, we find that lifespan extension by Ssd1 overexpression is accompanied by formation of cytoplasmic Ssd1 foci. The age-dependent Ssd1 foci are condensates that appear dynamically in a cell cycle-dependent manner and their failure to resolve during mitosis coincided with the end of lifespan. Ssd1 overexpression was epistatic with calorie restriction (CR) for lifespan extension and yeast overexpressing Ssd1 or undergoing CR were resistant to iron supplementation-induced lifespan shortening while their lifespans were reduced by iron chelation. The nuclear translocation of the Aft1 transcriptional regulator of the iron regulon occurred during aging in a manner that predicted remaining lifespan, but was prevented by CR. Accordingly, age-dependent induction of the Fit2 and Arn1 high-affinity iron transporters within the iron regulon was reduced by CR and Ssd1 overexpression. Consistent with age-dependent activation of the iron regulon, intracellular iron accumulated during aging but was prevented by CR and Ssd1 overexpression. Moreover, lifespan extension by Ssd1 overexpression or CR was epistatic to inactivation of the iron regulon. These studies reveal that CR and Ssd1 overexpression extend the yeast replicative lifespan by blocking deleterious age-dependent iron uptake, identifying novel therapeutic targets for lifespan extension.

The microstructural architecture of white matter supporting information flow across local circuits and large-scale networks changes throughout the lifespan. However, the genetic and cellular factors underlying age-related variations in white matter microstructure have yet to be established. Here, we examined the genetic associates of individual differences in diffusion-based measures of white matter in a population-based cohort (N=29,862) from the UK Biobank. Estimates of heritability from Genome-Wide Association Study (GWAS) data revealed that genetic factors are linked to population variability in 96.1% of 432 tract microstructural measures. The presence of shared genetic influences was observed to be greater within, relative to between, broad tract classes (commissural, association, projection, and complex cerebellar). Age associations with microstructural changes were estimated across diffusivity measures, with association class tracts showing the greatest vulnerability to age-related decline in older adults. Analyses of imputed cellular associates of age-related changes in white matter revealed a preferential relationship with cell gene markers of oligodendrocytes and other glial cell types, with sparse relationships observed for inhibitory and excitatory cells. These data indicate that white matter tract microstructure is shaped by genetic factors and suggest a role for glial cell-related transcripts in late-life changes in the structural wiring properties of the human brain.

The genetic tractability, well-mapped circuitry, and diverse behavioral repertoire of the nematode C. elegans make it an ideal model for physiological and behavioral studies. A wide range of methods has been developed for analyzing C. elegans behaviors, evolving with advances in technology such as videography and computer-assisted analysis. Here, we introduce LabGym-an open-source, artificial intelligence (AI)-based platform we recently developed-to the C. elegans research community. We trained deep learning models in LabGym capable of automatically categorizing and quantifying multiple user-defined parameters of worm locomotion behavior in multi-worm videos with high accuracy. Furthermore, we demonstrated their efficacy in quantifying locomotion changes in aging worms. Our work offers a cost-effective, user-accessible approach to behavioral analysis in C. elegans.

Aging is associated with profound changes in cellular function (senescence) and affects various tissues and systems, including the immune system (immunosenescence). Despite the increasing average age of individuals with multiple sclerosis (MS), little is known about what happens to the immune system of aging people with MS or about the impact of immunomodulatory and immunosuppressive treatments for MS on the aging immune system. In this topical review, we discuss the concepts of physiological cellular senescence and immunosenescence, and we review the latest available data on immunosenescence in MS. We examine evidence suggesting premature aging of the immune system in MS, including premature aging of T cells, reduced numbers of naïve lymphocytes, expansion of proinflammatory CD28- T cells, and the acquisition of an "aged" phenotype of CD8+ T cells in younger MS patients. Finally, we explore the clinical implications of immunosenescence on the efficacy and safety of disease-modifying therapies and propose drug candidates that could be tested in aged MS patients.

Age is the main risk factor for many neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and frontotemporal dementia. Despite our limited understanding of cellular mechanisms of aging-associated neuronal loss, an increasing number of studies demonstrate that oxidative stress and inflammation are key drivers. Epidemiological studies indicate that diet during middle adulthood can influence the risk of developing neurodegenerative diseases later in life, so it is important to investigate dietary interventions to combat oxidative stress and inflammation. In this study, we hypothesized that treatment with fucoxanthin, a marine carotenoid with strong antioxidant properties, prevents aging-associated oxidative stress that is known to be related to natural brain aging. Treatment with fucoxanthin protected rat primary hippocampal neurons against oxidative stress and aging

Chronic kidney disease (CKD) prevalence is rising globally due to an aging population. The role of physical activity (PA) in slowing age-related kidney function decline in the general population remains undecided.

Telomerase plays an important role in sustaining eukaryotic linear chromosomes, as elongation of telomeres is needed to counterbalance the shortening occurring in each replication round. Nevertheless, in telomerase-deficient cells, Alternative Lengthening of Telomeres (ALT) pathways can maintain telomeres by employing recombination-based mechanisms. In the budding yeast Naumovozyma castellii, effective activation of the ALT pathway leads to bypass of senescence and supports long-term growth. We found that telomere structures in N. castellii ALT cells are stably maintained at a shortened uniform length over extensive numbers of generations. This is correlated to the spreading of a subtelomeric sequence, TelKO element, to all telomeres. Genome sequencing of the wild-type strain revealed variants of the TelKO element, differing in their lengths, and separate ALT strains are maintained by spreading of distinct TelKO element variants. Although short uniform telomere structures are predominant, sporadic telomere lengthening events occur by addition of long repeated arrays of TelKO elements. The telomere-binding protein Rap1 can bind to TelKO sequences in vitro, indicating a functional role of TelKO elements in providing stability to shortened ALT telomeres. Our results suggest that stable maintenance and telomere functionality may be achieved by incorporating the distal subtelomeric TelKO sequences into the telomeric chromatin cap.

Muscle stem cells (MuSCs) are parenchymal cells in skeletal muscle regeneration and maintenance. With aging, MuSCs experience a decline in their regenerative function and reduction in their number. However, recent evidence points to substantial heterogeneity within the aged MuSC population, raising questions about the underlying mechanisms of age-associated dysfunction. Here, we used Pax7CreERT2;RosaYFP mice (MuSCYFP) to label Pax7-expressing MuSCs and chronologically traced MusCs until geriatric age. Genetic labeling and chronological tracing revealed that the number of YFP+ MuSC remained comparable between young, middle and geriatric ages. At geriatric age, YFP+ MuSCs exhibited reduced expression of traditional MuSC markers such as VCAM1 and PAX7. A previously unrecognized subpopulation emerged, characterized by loss of VCAM1 and low or absent PAX7. Despite their altered marker profile, these cells retained transcriptional signatures of quiescence and myogenic potential, but displayed significantly reduced proliferative and regenerative capacities. They displayed gene expression patterns indicative of senescence-like state and were selectively ablated by senolytic treatment. DHT restored regenerative function in aged mice and re-induced VCAM1 expression in YFP+/Pax7-/low/VCAM1- cells, indicating responsiveness to rejuvenation. Based on their emergence with aging, functional impairment and responsiveness to rejuvenation, we termed this population GERI-MuSCs (Geriatric Emerging Rejuvenation-responsive and Impaired MuSCs). CD63 and CD200 were identified as novel surface markers that together with VCAM1, reliably detect GERI-MuSCs as well as classical Pax7+/VCAM1High MuSCs, providing a tool for comprehensive isolation of MuSCs from aged wild-type mice. Together, our findings provide a refined framework for studying MuSC aging and offer new tools for isolating functionally distinct MuSC subsets from aged skeletal muscle.

Reactive oxygen species (ROS) and hydrogen sulfide (H

The NLRP3 inflammasome is an intracellular protein complex that causes inflammation via the release of IL-1β and pyroptosis. NLRP3 activation is associated with many age-related inflammatory diseases, and NLRP3 inhibition is a promising therapeutic strategy. We previously performed a DNA-encoded library screen to identify novel NLRP3-binding molecules. Herein we describe the characterization of BAL-0028 as a potent and specific inhibitor of NLRP3 signaling. Notably, BAL-0028 is a poor inhibitor of mouse NLRP3 but inhibits human and primate NLRP3 with nanomolar potency. Using cellular and biochemical analyses, we demonstrate that BAL-0028 binds to the NLRP3 NACHT domain at a site that is distinct from the MCC950-binding pocket. Using humanized NLRP3 mice, we show that a derivative of BAL-0028, BAL-0598, inhibits NLRP3 activation in vivo in a peritonitis model. Finally, we demonstrate that both BAL-0028 and BAL-0598 inhibit select hyperactive NLRP3 mutations associated with autoinflammatory diseases more potently than MCC950. BAL-0028 and BAL-0598 thus represent a new modality for NLRP3 inhibition in inflammatory diseases.

The sex chromosome aneuploidies Turner syndrome (45,X; TS) and Klinefelter syndrome (47,XXY; KS) are associated with aging-related comorbidities, reduced life expectancy and genome-wide DNA methylation changes. This indicates that biological aging, reflecting physiological function rather than chronological age, is increased in both syndromes. To investigate whether DNA methylation patterns linked to physiological decline could contribute to the comorbidity patterns and reduced lifespan in TS and KS, we applied so-called epigenetic clocks to DNA methylation data from cohorts of TS (n = 57) compared to female controls (n = 33) and KS (n = 65) compared to male controls (n = 63). Additionally, we evaluated correlations between epigenetic age and clinical variables, aiming to identify clinical aging markers in TS and KS.

Aging is the foremost risk factor for metabolic syndrome and atherosclerosis, which is a principal cause of cardiovascular diseases (CVDs). Vascular endothelial cells (ECs), which line the vascular intima, play a central role in maintaining vascular homeostasis. Their dysfunction, marked by impaired barrier function, inflammation, and metabolic dysregulation, constitutes an early and pivotal event in atherogenesis. As key sensors of hemodynamic forces, ECs are constantly exposed to blood flow-induced shear stress, which exert divergent effects on metabolism depending on the flow pattern. Laminar flow with relatively high shear stress (LS), as a critical atheroprotective factor, maintains EC quiescence and promotes anti-inflammatory responses and antioxidant defense, whereas disturbed flow with low and oscillatory shear stress (OS), induces the athero-susceptible signaling network to activate glycolysis and inflammation in ECs. While genetic, epigenetic, and molecular signaling mechanisms in EC physiology and pathophysiology have been extensively explored, the crucial role of EC metabolism in EC dysfunction and atherogenesis remains largely understudied. By serving as precursors, intermediates, and end products of cellular processes, metabolites offer a dynamic snapshot of endothelial metabolic states under both physiological and pathophysiological conditions. With aging, ECs undergo profound metabolic reprogramming, including disrupted glycolysis, mitochondrial dysfunction, and altered redox homeostasis. In healthy vasculature, ECs maintain quiescence and metabolic homeostasis, primarily relying on glycolysis for energy. With aging, the gradual accumulation of atherosclerotic risk factors, including oxidative stress, inflammation, dyslipidemia, and hyperglycemia, drives metabolic reprogramming in ECs, particularly in regions exposed to disturbed flow with OS, ultimately leading to EC dysfunction and atherosclerosis. This review summarizes recent advances in age-related metabolic reprogramming in ECs and its contribution to atherosclerosis, particularly focusing on the dysregulation of glycolysis, fatty acid metabolism, amino acid metabolism, and mitochondrial respiration induced by age and fluid shear stress. This review also outlines recent methodologies for profiling EC metabolism, and discusses potential therapeutic applications of targeting EC metabolism to prevent or delay the development of atherosclerosis.

Progressive loss of vascular smooth muscle cells (VSMCs) is the pathophysiological basis for aortic aneurysm and dissection (AAD), a life-threatening disease, but the underlying mechanisms are largely unknown. Sirtuin 6 (SIRT6), a class III histone deacetylase, is critical for maintenance of VSMC homeostasis and prevention of vascular remodeling-related diseases. In this study, we investigated the role of VSMC SIRT6 in AAD and the molecular mechanism. We showed that the expression levels of SIRT6 were significantly reduced in VSMCs of the thoracic aorta in AAD patients. We constructed a VSMC-specific Sirt6 deficient mouse line and found that loss of Sirt6 in VSMCs dramatically accelerated angiotensin II (Ang II)-induced AAD formation and rupture, even without an Apoe-deficient background. In human aortic smooth muscle cells (HASMCs), knockdown of SIRT6 led to mitochondrial dysfunction and accelerated VSMC senescence. We revealed that SIRT6 bound to and deacetylated NRF2, a key transcription factor for mitochondrial biogenesis. However, Sirt6 deficiency inhibited NRF2 and reduced mRNAs encoding mitochondrial complex proteins. Notably, MDL-811, a newly developed small-molecule SIRT6 agonist, effectively reversed Ang II-induced mitochondrial dysfunction in HASMCs. In a BAPN-induced TAAD mouse model, administration of MDL-811 (20 mg/kg, i.p., every other day for 28 d) effectively mitigated AAD progression and reduced mortality. These results suggest that SIRT6 plays a protective role against AAD development, and targeting SIRT6 with small-molecule activators such as MDL-811 could represent a promising therapeutic strategy for AAD.

Proper control of mTOR (mechanistic/mammalian target of rapamycin) signaling is relevant for health, disease and ageing. Information from intra- and extra-cellular signaling cues is transmitted to mTOR through an intricate signaling network that impinges on the Rag and Rheb GTPases to regulate its localization and activity. Interestingly, although mTOR is a heavily ubiquitinated protein, the role of this post-translational modification (PTM) in regulating its activation status remains poorly understood. Here, through an unbiased RNAi screen, we identified the tumor suppressor CYLD deubiquitinase (DUB) as a direct negative regulator of both mTORC1 and mTORC2 activities. Mechanistically, CYLD interacts with mTOR and removes non-degradative, K63-linked ubiquitin (Ub) chains from multiple of its residues. Consequently, CYLD loss-of-function cells are characterized by mTORC1/2 hyperactivation, elevated rates of protein synthesis, increased cell size, and resistance to serum-starvation-induced activation of cell death pathways. Moreover, silencing of cyld-1, the C. elegans CYLD ortholog, fully reverses the extended lifespan of low-TORC1-activity mutant worms. Finally, we find that inactivation of CYLD is associated with hyperactivation of mTORC1 also in skin biopsies from CYLD cutaneous syndrome (CCS) patients. In sum, our findings highlight CYLD as a sentinel of mTOR hyperactivation via direct control of its ubiquitination, and suggest that dysregulated mTOR activity may contribute to the development and progression of CCS tumors.

Osteoarthritis is a prevalent joint disease in the aging population. The hallmark of osteoarthritis is the degeneration of the joint cartilage, characterized by changes in chondrocytes including mitochondrial dysfunction. However, the precise mechanisms of how this affects chondrocyte homeostasis and whether such processes can be explored as therapeutic targets for osteoarthritis remain unclear. Here, we show that impaired mitochondrial function and disrupted cartilage matrix metabolism due to loss of mitofusin-2 (MFN2) expression in chondrocytes leads to the development of osteoarthritis. Sirtuin-3 (SIRT3), a key regulator of mitochondrial function, plays a critical role in modulating MFN2 to restore mitochondrial dynamics, reduce fragmentation, and preserve mitochondrial function in chondrocytes. Specifically, SIRT3 directly deacetylates and indirectly deubiquitinates MFN2, preventing its degradation. MFN2-mediated mitochondrial-endoplasmic reticulum (ER) junctions support cellular homeostasis, alleviate ER stress, and maintain mitochondrial calcium ion balance, which collectively mitigate chondrocyte senescence. Extracellular vesicles engineered with MFN2 mRNA effectively prevented cartilage degeneration and restored mobility in osteoarthritic mice. These findings suggest that targeting MFN2 is a promising strategy to prevent cartilage degeneration and alleviate progression of osteoarthritis.

To explore whether older adults with sarcopenia are at greater risk for falls, fractures, hospital readmissions, and all-cause mortality compared to those without sarcopenia.

Ovarian aging significantly contributes to the decline of the female reproductive system, adversely affecting fertility and endocrine homeostasis. To address the challenges posed by reproductive aging, natural products have shown promising preventive and therapeutic effects. Here, we investigated the beneficial effects of natural compound celastrol on ovarian development and aging, together with its underlying mechanisms. We found that celastrol administration at a concentration of 3 mg/kg promoted follicle development in young mice and enhanced porcine oocyte maturation, while regulating granulosa cell proliferation and apoptosis. In 12-month-old mice (equivalent to middle-aged adults), celastrol exhibited similar beneficial effects. Transcriptomic analysis revealed that differentially expressed genes post-celastrol treatment were associated with steroid biosynthesis, estrogen signaling pathways, type 2 diabetes, insulin secretion, meiosis, and apoptosis. Additionally, insulin receptor substrate 1 (IRS1), an adapter protein in insulin signaling, was shown to advance puberty in young mice and to facilitate oocyte maturation. Overexpression of IRS1 in oocytes promoted follicular development and oocyte maturation, resulting in enhanced steroid hormone levels, whereas IRS1 knockdown inhibited these processes. Our findings indicate that celastrol may regulate ovarian development and aging by modulating IRS1 expression and its related pathways, suggesting celastrol as a novel small-molecule compound targeting IRS1, and offering new perspectives for potential therapeutic strategies against reproductive aging and infertility.

Sulfur mustard (SM), a chemical warfare agent, inflicts severe acute and chronic health effects. This study investigates the impact of SM-induced oxidative stress on telomere length (TL) and shelterin gene expression, which are crucial for telomere maintenance in exposed veterans. This study involved SM-exposed veterans and non-exposed controls. The SM-exposed group was divided into three subgroups based on exposure severity (severe, mild, and asymptomatic) and gender. Leukocyte TL, transcript of shelterin genes (TPP1, POT1, TIN2, TRF1, TRF2, RAP1), and plasma MDA were measured. TL was decreased in the SM-exposed group compared to the non-exposed group, while the MDA level was increased. The SM-exposed group showed lower expression of TIN2, TRF2, and the composite shelterin genes compared to the control group. In the SM-exposed subgroups, TL, TRF2 transcript, and composite shelterin gene expression were reduced compared to the non-exposed group, while the MDA levels were significantly increased. There are negative correlations between MDA and both TIN2/TRF2 expression and TL, and positive correlations between TL and composite shelterin gene expression. In the gender comparison, there were different effects of SM toxicity on TIN2, TPP1, TRF2, and the composite of shelterin gene expression between SM-exposed men and women. SM-exposed men had significantly higher MDA levels, while women showed no significant change. Also, there was no difference between non-exposed men and women. It is concluded that SM exposure increases lipid peroxidation, shortens telomeres, and alters shelterin genes in a gender-specific manner, suggesting accelerated biological aging as a delayed toxic effect.

Human mesenchymal stem cells (MSCs) have demonstrated promise when delivered to damaged tissue or tissue defects for their cytokine secretion and inflammation modulation behaviors that can promote repair. Insulin-like growth factor 1 (IGF-1) has been shown to augment MSCs' viability and survival and promote their secretion of cytokines that signal to endogenous cells, in the treatment of myocardial infarction, wound healing, and age-related diseases. Biomaterial cell carriers can be functionalized with growth factor-mimetic peptides (i.e. IGF-1 mimicking peptides) to enhance MSC function while promoting cell retention and minimizing off-target effects seen with direct administration of soluble growth factors. Here, we functionalized alginate hydrogels with three distinct IGF-1 peptide mimetics and the integrin-binding peptide, cyclic RGD. One IGF-1 peptide mimetic (IGM-3) in combination with integrin ligand was found to activate Akt and ERK1/2 signaling and support survival of serum-deprived MSCs. MSCs encapsulated in alginate hydrogels that presented both IGM-3 and cRGD showed a significant reduction in pro-inflammatory cytokine secretion when challenged with interleukin-1 {beta}. Finally, MSCs cultured within the cRGD/IGM-3 hydrogels were able to blunt pro-inflammatory gene expression of human primary cells from degenerated intervertebral discs. These studies indicate the potential to leverage cell adhesive and IGF-1 growth factor peptide mimetics together to control therapeutic secretory behavior of MSCs.

Living in historically redlined neighborhoods has deleterious effects on aging-related health outcomes, yet little is known about how historical redlining affects the physiological aging process and the role of current neighborhood socioeconomic status (SES) on this relationship. This study determined if living in historically redlined neighborhoods was associated with biological age and if this association was mediated by neighborhood-level socioeconomic status. We linked the Health and Retirement Study 2016 Venous Blood Study (HRS-VBS) to redlining scores from the Historic Redlining Indicator data and census tract level data from the 2014-2018 American Community Survey 5-year estimates (N = 6,466 respondents). Multivariable linear regression models were used to assess differences in biological age among older residents of historically redlined neighborhoods graded "Best/Desirable", "Declining", and "Hazardous". Mediation analyses using the khb method were used to assess whether measures of neighborhood affluence and disadvantage explained differences in biological age by historical redlining grade. Older residents of "Declining" or "Hazardous" neighborhoods were about 2.5 and 1.7 years older biologically than residents of "Best/Desirable" neighborhoods. Neighborhood SES mediated this relationship, with affluence explaining approximately 20% and disadvantage explaining about 8% ("Declining") and 25% ("Hazardous") of the association between historical redlining and biological age. Our study highlights the importance of evaluating measures of physiological functioning and current neighborhood conditions to clarify existing health disparities among residents of historically redlined neighborhoods.

We explored whether changes in serum proteomic profiles differed between participants with distinct brain aging trajectories, and whether these changes were influenced by dietary intervention.

Extending human healthspan requires understanding how lifestyle interventions impact molecular systems across tissues and time. Here, we present the TirolGESUND Lifestyle Atlas (ClinicalTrials.gov: NCT05678426), a longitudinal, multi-modal resource profiling 156 healthy women (aged 30-60 years) undergoing 6-month intermittent fasting (n=114) or smoking cessation (n=42) interventions. Participants were sampled up to four times across seven tissues and fluids, generating >3,450 biospecimens with harmonised DNA methylation, metabolomics, microbiome, and immune profiling, alongside skin histology, barrier measurements, and rich clinical metadata. We demonstrate the utility of this dataset through: (i) multi-omics-wide association studies linking traits to molecular features; (ii) integrative factor modelling revealing coordinated cross-tissue signatures; (iii) epigenetic-biomarker cross-omic associations, and (iv) CpG-level variance decomposition mapping stable, individual-specific, tissue-restricted, and intervention-responsive methylation patterns. We further show that ageing-linked features are selectively malleable: highly compliant intermittent fasting participants exhibited attenuated or even age-opposing molecular trajectories within six months. The atlas enables unprecedented within-cohort comparisons across omic layers and tissues, supporting discovery of context-dependent biomarkers, cross-system coordination, and intervention responsiveness. Data are available via an interactive portal, with sensitive data under controlled access (https://eutops.github.io/lifestyle-atlas/). This resource provides a foundation for exploring biomarker association and multi-tissue epigenetics, enabling hypothesis generation and benchmarking for systems biology and human healthspan research.

Oct4, Sox2, and Klf4 (OSK) Yamanaka factors induce pluripotency and reverse age-related epigenetic changes, yet the mechanisms by which they promote rejuvenation remain poorly explored. Oxidative stress contributes to CNS aging and retinal pigmented epithelium (RPE) degeneration in age-related macular degeneration. We find that OSK expression in RPE restores retinal structure and visual function in aged mice and promotes oxidative resilience through a non-canonical, Tet2-independent pathway. Integrative functional genomics identifies GSTA4, a detoxifying enzyme that clears the lipid peroxidation byproduct 4-HNE, as a necessary and sufficient OSK effector. Dynamic GSTA4 regulation by OSK recapitulates a stem cell derived stress resilience program. GSTA4 overexpression alone enhances mitochondrial resilience, rejuvenates the aged RPE transcriptome, and reverses visual decline. GSTA4 is consistently upregulated across diverse lifespan-extending interventions suggesting a broader pro-longevity role. These findings uncover a previously unrecognized protective axis driven by Yamanaka factors that circumvents reprogramming, providing therapeutic insights for age-related diseases.

While most knowledge of animal DNA methylation comes from vertebrates, this epigenetic mark remains poorly understood in invertebrates, which comprise the majority of animal diversity. For instance, how promoter and gene body methylation contribute to gene regulation, and how methylation relates to aging, are still relatively unknown in most invertebrates. Focusing on the California mussel (Mytilus californianus), we paired whole-genome resequencing and whole-genome bisulfite sequencing from the same individuals and evaluated relationships among promoter methylation, gene body methylation, gene expression, and age. Using seven individuals spanning a range of body sizes from the Santa Barbara Channel, California, we found standing genetic variation levels similar to related species and a relatively small effective population size. CpG methylation was enriched in gene bodies, and gene body methylation was positively associated with expression. Promoter methylation was less frequent but showed a strong negative association with expression and remained the best predictor of repression after accounting for gene body methylation, aligning with patterns widely documented in vertebrates and adding to the limited evidence in invertebrates that promoter methylation can be regulatory. We identified thousands of age-associated differentially methylated loci with directional changes across age classes, providing candidate sites for epigenetic clocks that could enable assessment of biological age, health, and stress resilience in wild and cultured populations.

Repetitive transcranial magnetic stimulation (rTMS) is an attractive tool to promote healthy brain ageing in older adults and treat age-related neurological conditions. Despite its popularity, the neurological processes and plasticity mechanisms altered by rTMS in the aged brain, and where these changes occur in the brain are unknown. Furthermore, it is not known why different rTMS protocols induce different changes in the aged brain, or why rTMS is less effective in older adults compared to younger adults. Using spatial transcriptomics, we uncovered that rTMS primarily acts on genes related to synaptic plasticity in both cortical and subcortical circuits in aged mice, but the specific changes were dependent on the brain region and even down to individual cortical layers in the motor and somatosensory cortices. Comparing our results from aged mice to young adult mice revealed that rTMS acts on a larger variety of neural plasticity mechanisms in the young adult brain, and that rTMS was less effective at altering gene expression related to neural plasticity in the aged brain, but this varied between brain regions and the protocol of rTMS applied. These findings provide a comprehensive map of the mechanisms altered by rTMS across the aged brain and highlight the need to consider the effect of ageing when optimising rTMS protocols for older populations.

This study aimed to explore the association between physical activity (PA) levels and major health issues (obesity, hypertension, and diabetes mellitus) and mental health factors (depression, stress, suicidal thoughts, and cognitive impairment) among South Korean baby boomers (BBs) to help improve national health policies. Given the global trend of aging populations and the increasing burden of non-communicable diseases, understanding the role of PA in promoting healthy aging has become a critical public health issue not only in South Korea but also worldwide.

Wildland fires in the United States have increased in frequency and scale over the past 30 years exposing millions of people to hazardous air pollutants. Among others, aging individuals are particularly vulnerable to the effects of wildfire smoke. In this study, we assessed the neurobiological impacts of wood smoke (WS) on aged mice and the potential of anti-aging therapeutics to mitigate these impacts.

While grip strength (GS) is recognized as a feasible predictor of various health outcomes, its association with healthy aging and the role of plasma proteins remain unclear.

Physical activity (PA) has many health benefits. However, more research is needed to understand its effects on mortality risk in older adults.