GeroScience

Antagonistic pleiotropy of the IGF-1 signaling cascade is well recognized, as it promotes growth and development at younger ages and delays aging later in life. The goal of this study is to test in a mouse longevity experiment whether orally delivered small-molecule IGF1R inhibitors have promise as an anti-aging therapy. C57BL/6 mice (25 male and 25 female mice per treatment) were treated with selective IGF1R inhibitors, picropodophyllin (PPP) or 5-[3-(phenylmethoxy)phenyl]-7-[trans-3-(1-pyrrolidinylmethyl)cyclobutyl]-7H-pyrrolo[3-d]pyrimidin-4-amine (NVP-ADW742), via powdered diets starting at 13 months of age, and physiological and behavioral parameters, as well as survival, were assessed. Both compounds protected both sexes from short-term memory decline; reduced systolic blood pressure in males and pulse rate in both sexes; rescued declining glucose tolerance in males; and abolished grey hair development, reduced frailty, and protected against decline in grip strength in female mice. There were no sex differences in survival curves within groups. No significant differences between groups were observed in the Kaplan-Meier analysis. However, the survival curve in the NVP-ADW742 group was "squarer" than in controls, indicating a 93-day longer healthspan (p = 0.02). PPP treatment was associated with toxicity (GI bleeding). Additional analysis of the drug likeness of NVP-ADW742 demonstrated potential cardiotoxicity and brain bioaccumulation. To conclude, small-molecule IGF1R inhibitors hold promise as a therapy that may improve human health span and lifespan; however, both molecules tested in this study have side effects that may outweigh their anti-aging effects. Statements and DeclarationsYB is an employee of ReGENE LLC. GB received compensation from ReGENE LLC as a consultant. CJE received compensation from and is a member of ReGENE LLC. AS received compensation from and is a member of ReGENE LLC. TS declares no conflict of interest.

CD31+ T-cells reportedly possess angiogenic properties. These cells have recently been termed angiogenic T-cells (TANG). Advancing age is associated with altered circulating T-cell phenotypes, including TANG, and reduced angiogenesis. We examined various TANG subsets (CD3+, CD4+, CD8+), and their VEGF-A intracellular content in young (n=16, 18-30 years) and older (n=16, 50-65 years) male adults using flow cytometry. Cardiorespiratory fitness ([V]O2max) was quantified in all participants using a graded cycling ergometry test to volitional exhaustion. Resting blood samples were collected to measure circulating IL-6 and cytomegalovirus serostatus. CD31+ T-cells (TANG) contained more VEGF-A than CD31- T-cells (CD31+: 9374 {+/-} 8587 AU vs CD31-: 8722 {+/-} 8149 AU, p = 0.021) which was also exhibited in CD4+ and CD8+ subsets. Older adults possessed fewer CD4+ TANG cells as a proportion of total CD4+ T-cells than younger adults (young: 35 {+/-} 11%; older: 24 {+/-} 9%, p = 0.004), and CD3+ and CD4+ TANG subsets from older adults exhibited higher VEGF-A levels than younger adults (CD3+CD31+: young: 6081 {+/-} 4001 AU; older: 13426 {+/-} 10945 AU, p = 0.019; CD4+CD31+: young: 6373 {+/-} 3972 AU; older: 15660 {+/-} 12829 AU, p = 0.011). TANG cells were not associated with circulating IL-6, and TANG VEGF-A content was not associated with[V] O2max. Advancing age is associated with a pathological TANG phenotype, which may contribute to age-related inflammation and warrants further investigation as a potential therapeutic target.

Heart rate variability (HRV) is widely used to assess autonomic regulation, but its interpretation in older adults is influenced by age, sex, body composition, and hemodynamic status, particularly in underrepresented populations living in geographically extreme environments. We analyzed 530 community-dwelling older adults from the Magallanes region in southern Chile using an integrated framework that combined HRV indices with demographic, anthropometric, and cardiovascular descriptors. After quality-controlled preprocessing, we characterized the distribution and association structure of autonomic and physiological variables and then performed a large-scale unsupervised clustering benchmark across multiple feature spaces, dimensionality-reduction strategies, and clustering algorithms. Conventional descriptors explained only a limited proportion of HRV variability, whereas integrated multivariate analysis revealed a structured continuum of autonomic heterogeneity. A six-cluster solution provided the best compromise between separation, balance, and physiological interpretability, identifying profiles that differed in HRV magnitude, blood pressure burden, body composition, sex distribution, and age structure. These findings indicate that autonomic regulation in older adults cannot be adequately summarized by isolated descriptors such as age, body mass index, or blood pressure alone. Instead, it is better represented as a multidimensional physiological organization that supports future hypothesis generation for risk stratification and longitudinal monitoring in aging populations.

Frailty is a multi-system syndrome causing increased susceptibility to health insults in older adults. Immune system dysregulation and inflammaging have emerged as mechanisms that may affect multiple organ systems in the frailty syndrome. This present study seeks to define the immune state in community-dwelling adults suffering from frailty. We evaluated a subgroup of 169 individuals enrolled in the Gut-brain Alzheimers disease Inflammation and Neurocognitive Study (GAINS). Participants in the GAINS study were scored for frailty using the Clinical Frail Scale. A panel of 27 inflammatory cytokines was analyzed from the serum of each participant. Frailty was present in 33 (19.5%) of the cohort, and was correlated with age, malnutrition, and cognitive assessments. Statistical analysis adjusting for clinical covariates revealed higher serum levels of IL-2, IL-10, and IL-17 in frail patients. Using machine learning classification, we developed a predictive model of frailty with strong discriminative performance (AUC 0.78). Individual element analysis via Shapley Additive Explanations (SHAP) revealed that inflammatory markers had the greatest influence on the model, and IL-7 was the single most important element in the prediction of frailty. Together, our data demonstrate a novel pattern in which T-cell regulatory inflammatory molecules as mediators of frailty, implicating cellular immunity as a potential mechanism of dysfunctional aging.

BackgroundOlder adulthood is often accompanied by declines in auditory processing and cognitive functioning, increasing the risk of reduced autonomy and quality of life. Multidomain lifestyle interventions have shown potential to counteract these changes, and choir-based activities represent a promising approach by simultaneously engaging auditory, cognitive, physical, and social domains. However, evidence regarding their feasibility and neurophysiological impact in community-dwelling older adults, particularly those without formal musical training, remains scarce. MethodsThis 9-month quasi-experimental feasibility study involved 54 community-dwelling older adults (mean age = 72.9 years) with no formal musical background. Participants self-selected into a choir-based intervention group, an active control group engaging in non-musical leisure activities, or a passive control group; however, some participants in the control groups were selected from the waiting list for the choir. Assessments were conducted at baseline and follow-up and included measures of global cognition, cognitive reserve, psychological well-being (Flourishing Scale), multidimensional frailty (Selfy-MPI), music perception, pure-tone audiometry, and auditory evoked potentials recorded using a standardized clinical oddball paradigm. ResultsThe choir-based intervention was feasible in a community setting. At the neurophysiological level, choir participation was associated with a bilateral, significant shortening of the N2-P3 inter-peak latency, indicating faster auditory-cortical processing. Additionally, through explorative analyses multidimensional frailty, as assessed by the Selfy-MPI, showed a significant reduction in individuals engaging in a higher number of activities, irrespective of group allocation. Similarly, psychological well-being revealed a decrease in flourishing scores in the passive control group relative to the choir group. No changes were observed in audiometric thresholds or music perception measures. ConclusionChoir-based multidomain participation is a feasible intervention for community-dwelling older adults without formal musical training and is associated with selective benefits in cognitive reserve, psychological well-being, auditory-cortical processing speed, and multidimensional frailty. These findings provide a foundation for a larger randomized controlled trial aimed at clarifying the cognitive, psychosocial, and neural mechanisms underlying choir-based interventions in ageing. Trial RegistrationThe upcoming trial has been prospectively registered on ClinicalTrials.gov (ID: NCT06767410; registration date: January 9, 2025).

Multiscale entropy (MSE) changes in relation to age, whereby aging is associated with an increasing bias towards fine scale entropy. This change is thought to represent a shift toward localized information processing in the brain as we age. However, this relationship has not been tested in large sample sizes alongside other demographic factors and cognitive behaviours. This study aimed to validate previously reported effects of aging on MSE in a large open access database (Cambridge Centre for Ageing and Neuroscience, N=587) and expand the findings to include an investigation of the effects of sex and a variety of cognitive behaviours. MSE curves and power spectrum densities (PSD) were calculated for each region of interest from the magnetoencephalography data. Multivariate partial least squares analyses were used to assess the relationship between MSE or PSD and 5 behavioural / demographic factors including: age, sex, fluid intelligence, visual short-term memory and a generalized measure of cognitive function. Age was associated with increased fine scale and decreased coarse scale entropy, as well as complementary spectral changes, including slowing of peak alpha rhythms, increased beta-band activity, and reduced gamma-band activity, which replicates prior MSE and PSD findings. In both domains, these age-related patterns differentiated based on sex with advancing age. Importantly, the unique effects of sex diverged between MSE and PSD. This result indicates that entropy-based measures can isolate aspects of temporal organization that are not clearly summarized by spectral structure alone.

Protein misfolding plays a critical role in aging and disease, yet the involvement of specific proteins in metabolic dysfunction is still poorly understood. Here, we report studies on the development of a Real-time Quaking-Induced Conversion (RT-QuIC) assay to detect misfolded insulin, a peptide hormone required for blood glucose regulation. Although RT-QuIC assays were originally designed to amplify misfolded prion proteins implicated in neurodegeneration, we adapted the method to monitor conformational changes in insulin. We first validated the RT-QuIC insulin assay using recombinant insulin and insulin aggregates recovered from clinical infusion devices. Protein characterization by gel electrophoresis, circular dichroism, and particle size analysis suggests differences in insulin recovered from the infusion device. We then applied the RT-QuIC assay to tissue samples from a mouse model of metabolic disease. This work provides proof-of-concept of a novel assay for studying the role of insulin aggregation in disease progression and aging. The RT-QuIC assay for insulin may also provide new avenues to explore early detection, mechanistic insights, and therapeutic targets of metabolic disorders linked to aging and disease.

Background: Ageing is a systems level biological process underlying the onset and progression of multiple chronic disorders. Rather than arising from a single pathway, age related decline reflects interacting disturbances in metabolic regulation, inflammation, nutrient sensing, cellular stress responses, and tissue repair. Although GLP1 receptor agonists, sodium glucose cotransporter2 inhibitors, metformin, and rapamycin are usually evaluated against disease-specific endpoints. Objective: To develop an SBML compliant quantitative systems pharmacology model in which ageing is the primary pharmacological endpoint and to evaluate which combination therapy provides the greatest benefit for both metabolic and ageing related outcomes. Methods: We developed model comprising four layers: a metabolic/pharmacodynamic layer describing weight loss, HbA1c reduction, and nausea with tolerance; a drug layer capturing class-specific effects of GLP1 agonists, sodium glucose cotransporter2 inhibitors, metformin, and rapamycin; an ageing layer representing damage accumulation, repair capacity, frailty, and biological age gap; and a biomarker layer generating trajectories and estimated glucose disposal rate. Calibration was staged across semaglutide clinical endpoints. Bayesian hierarchical meta analysis, global sensitivity analysis, and practical identifiability analysis were used to assess robustness and interpretability. Results: The model reproduced semaglutide efficacy and tolerability dynamics and supported distinct drug-class profiles across metabolic and ageing axes. Rapamycin showed minimal glycaemic effect but emerged as a dominant driver of repair related ageing outcomes. Combination simulations predicted two distinct optima: one favouring metabolic improvement and one favouring ageing related benefit. Conclusion: The model supports the view that metabolic and ageing optimization are mechanistically distinct objectives and that weight loss and glycaemic improvement alone may be insufficient surrogates for health span benefit.

Frailty arising from loss of muscle function and mass is a significant health concern impacting quality of life and dramatically increasing health care costs as our population ages. Ameliorating frailty derived from reduced muscle function is thus a critical research priority to improve health span. Cell intrinsic defects in muscle stem cells (MuSC), or satellite cells, occur as skeletal muscle ages, reducing the capacity of MuSCs to maintain and repair skeletal muscle and are accompanied by cell nonautonomous changes. Although rejuvenating stem cells in aged tissues or organs has potential to improve muscle aging phenotypes, we found that the extracellular environment in aged mice abrogates rejuvenated muscle stem cell potential. MuSCs from young mice were unable to grow on extracellular matrix derived from aged mice that contains elevated collagen protein levels, establishing a critical role for the environment in contributing to muscle phenotypes in aging. Combining an inducible FGF receptor 1 (FGFR1) to rescue MuSC intrinsic aging defects with a drug to reduce fibrosis partially rescued muscle mass loss in aged mice. We conclude that aging affects tissues, and particularly skeletal muscle tissue, via complex multifactorial processes requiring multifaceted interventions to improve aging phenotypes.

BackgroundGenome-wide studies in late-onset Alzheimers disease (LOAD) have uncovered many risk loci, yet identifying the causal genes and clarifying how these genetic signals connect to molecular and cellular mechanisms relevant to AD pathogenesis in vivo remains challenging. MethodsUsing Caenorhabditis elegans as a model to identify LOAD-associated genes that drive neurodegenerative processes, we focused on 14 understudied genes and their homologs: ABI3/abi-1, B4GALT3/bre-4, CCDC6/T09B9.4, CLPTM1 (two homologs C36B7.6 and R166.2), CNN2/cpn-2, DMWD/wdr-20, ECHDC3/ech-2, MADD/aex-3, NCK2/nck-1, RABEP1/rabn-5, RIN3/rin-1, SLC39A13/zipt-13, TRAM1/tram-1, and USP6NL/tbc-17. We knocked down these genes by RNAi and quantified lifespan, aging-associated degeneration of two neuron classes, PVD and PLM, and associative learning and short-term memory. ResultsLifespan was unaffected by most knockdowns, and only nck-1 and tbc-17 shortened lifespan. Across neuronal assays, multiple homologs modulated aging with clear neuron-class selectivity. Knockdown of aex-3, C36B7.6, cpn-2, ech-2, rabn-5, rin-1, T09B9.4, and zipt-13 attenuated late-life PVD degeneration, whereas R166.2 and tram-1 accelerated early PVD aging. Only two genes affected PLM aging: R166.2 knockdown exacerbated degeneration, while tbc-17 knockdown attenuated it despite its lifespan-shortening effect. In PLM neurons, tbc-17 knockdown, targeting a Rab GTPase-activating protein, also preserved mitochondrial architecture during early aging and shifted heat stress-induced mitochondrial remodeling toward a pattern consistent with improved quality control. In behavioral assays, ech-2 knockdown, targeting an enoyl-CoA-hydratase, enhanced short-term memory during early stages of aging. To further assess how LOAD-linked genes interact with A{beta}-driven neurodegeneration, we developed a model that combines the PVD aging assay with a background expressing human A{beta}1-42 panneuronally. In this model, A{beta} expression accelerated age-dependent PVD degeneration, whereas ech-2 knockdown abolished this A{beta}-induced effect. ConclusionsOur findings show that conserved homologs of several understudied LOAD risk genes causally modulate neuronal aging in vivo in a neuron-class-selective manner, often dissociable from organismal longevity. This C. elegans framework translates human genetic associations into quantitative, aging-linked neuronal phenotypes, and our results further emphasize early endosomal and lipid-related processes as key pathways that warrant functional testing in neuronal aging. This study also provides a tractable platform to prioritize targets for cross-species validation and to test synergy with established LOAD risk genes.

Objectives. The association between skeletal muscle gene expression and knee osteoarthritis (OA) was examined among older adult participants of the Study of Muscle, Mobility and Aging (SOMMA). Methods. Inclusion criteria included knee radiographs and bulk RNA sequencing (RNAseq) in vastus lateralis muscle, resulting in 523 participants (56% female). Radiographic knee OA was determined by Kellgren-Lawrence (KL) grades. Differential gene expression was analyzed using a control group (KL [≤] 1, n = 326) and two nested case groups: (a) KL [≥] 2 (n = 197), (b) KL [≥] 3 (n = 112). Results. Compared with controls, there were 27 and 41 genes associated (FDR [≤] 0.05) with KL [≥] 2 and KL [≥] 3, respectively, and 16 genes significantly associated in both contrasts. For 15 of the 16 genes, the association magnitude was larger with more severe OA (KL [≥] 3). Genes associated in both contrasts included brain-derived neurotrophic factor (BDNF) and interferon regulatory factor-2 (IRF2). Gene sets enriched in KL [≥] 2 and KL [≥] 3 contrasts included DNA repair and branched chain amino acid (BCAA) catabolism. Conclusions. Our results in older adult SOMMA participants indicate that knee OA is associated with genes and pathways expressed in skeletal muscle that are involved in pain sensitization, BCAA catabolism, muscle function preservation, calcium transport and storage, inflammation, and extracellular matrix remodeling. Additional longitudinal studies will be needed to determine how these genes could affect the progression of knee OA.

Background: The role of biological age acceleration (BioAgeAccel) in the dynamic progression from single cardiovascular-kidney-metabolic disease (CKMD) to multimorbidity, and subsequently to dementia and mortality remains elusive. Methods: We conducted a longitudinal study with data of 433,911 UK Biobank participants. Cardiovascular-kidney-metabolic multimorbidity (CKMM) was defined as the coexistence of two or more CKMDs, including cardiovascular disease (CVD), stroke, type 2 diabetes (T2D), and chronic kidney disease. Biological aging was measured via PhenoAge and KDM-BA. Multistate models examined the association between BioAgeAccel and disease transitions, ranging from healthy to the first occurrence of CKMD (FCKMD), then progression to CKMM, dementia, and mortality. Restricted mean survival time estimated the disease transition time or life expectancy between states. Results: BioAgeAccel was significantly associated with increased risks across all disease transitions. Specifically, during CKMM progression, the hazard ratios (HRs) of the transition from healthy to FCKMD were 1.24 [95%CI 1.23-1.25] for PhenoAgeAccel and 1.16 [1.15-1.17] for KDM-BA-Accel. For subsequent transition to CKMM, the HRs were 1.20 [1.18-1.22] and 1.19 [1.17-1.21], respectively. In dementia-related transitions, PhenoAgeAccel showed the higher risk for CKMM to dementia (HR=1.13 [1.04-1.22]) than for the transition from healthy or from FCKMD to dementia. These associations were further moderated by age, physical activity, educational, and lifestyle factors. BioAgeAccel also accelerated disease progression and reduced life expectancy; for example, during CKMM progression, BioAgeAccel shortened the time between disease transitions by about 1.09 years from healthy to FCKMD, and an additional 1.75 years to CKMM. Regarding life expectancy, individuals with CKMM experienced an average reduction of about 1.36 years under PhenoAge, while those with dementia showed a decrease of about 0.77 years. Among individuals with CVD or T2D as the initial diagnosis, the impact of BioAgeAccel on progression to CKMM or dementia was stronger. Conclusions: BioAgeAccel exerts significant promotive role in the onset of CKMD and their subsequent progression to CKMM, dementia, and mortality, helping identify high-risk individuals. Implementing biological age assessments and health lifestyle interventions in middle-aged populations serves as an effective strategy for alleviating the burden of CKMDs and dementia.

Background: Prediabetes is highly prevalent in older adults and is characterized by heterogeneous clinical trajectories, including regression to normoglycemia and progression to diabetes. While prediabetes has been associated with impaired physical function and frailty, the longitudinal impact of both a single diagnosis and dynamic glycemic transitions on functional outcomes remains unclear. We aimed to evaluate associations between baseline prediabetes and glycemic transitions over time with trajectories of functional capacity and frailty in older adults. Methods: We conducted a pooled analysis of harmonized data from five nationally representative longitudinal aging cohorts (MHAS, HRS, CHARLS, ELSA, CRELES) within the Gateway to Global Aging Data, including adults aged [≥]50 years with [≥]1 HbA1c measurements. Prediabetes was defined per ADA criteria (HbA1c 5.7-6.4%). Functional outcomes included activities of daily living (ADL), instrumental ADL (IADL), and frailty assessed using Fried phenotype, FRAIL scale, and a deficit-accumulation Frailty Index (FI). Mixed-effects Poisson models estimated incidence rate ratios (IRRs) for baseline prediabetes, while generalized estimating equations assessed time-varying glycemic status and transition trajectories. Models were adjusted for age, sex, cohort, and time-varying covariates, with sensitivity analyses including BMI, smoking, and alcohol intake. Findings: Among 18,571 participants (median follow-up 13.6 years), baseline prediabetes was associated with increased progression of functional deficits and frailty compared with normoglycemia, including higher FI values and accelerated FI progression. Prediabetes was associated with higher incidence of ADL, IADL, and multimorbidity deficits from early follow-up, although time-dependent changes in incidence rates were not significant. In time-varying analyses (n=7,840), both prediabetes and diabetes were associated with higher incidence of functional deficits compared with normoglycemia, with diabetes showing the strongest effects across all outcomes. Diabetes was associated with greater FI burden and accelerated progression, whereas prediabetes showed a smaller increase, with attenuation over time. Among individuals with baseline prediabetes, regression to normoglycemia occurred in 20.8% and was associated with increased incidence of ADL and frailty deficits. In contrast, progression to diabetes occurred in 24.3%, and was associated with lower risk of incident ADL and Fried frailty deficits compared to stable prediabetes. Interpretation: Prediabetes is associated with increased risk of functional decline, frailty, and deficit accumulation in older adults, independent of progression to diabetes. Regression to normoglycemia was associated with higher risk of functional deterioration. These findings suggest that prediabetes reflects a state of metabolic vulnerability linked to biological aging rather than solely a precursor to diabetes and highlights a need to reframe its clinical significance in older populations. Funding: This research was supported by Instituto Nacional de Geriatria in Mexico. Keywords: Prediabetes; Glycemic transitions; Frailty; Functional decline; Aging; Multimorbidity

Most evidence on age-related network topology derives from resting-state paradigms, leaving unclear how aging alters brain organization during naturalistic processing and whether graph-theoretical metrics relate to emotional and cognitive functioning in ecologically valid contexts. We analyzed movie-fMRI and behavioral data from 72 younger and 68 older adults, examining global (small-worldness, clustering coefficient, characteristic path length), network (participation coefficient), and nodal (degree centrality, betweenness centrality, nodal efficiency) properties. Regression models were used to test associations between nodal measures and both the Emotional Resilience Index (ERI) and the Cognitive Function Index (CFI), while mediation analyses were conducted to test whether nodal measures mediate the relationship between age and ERI. Older adults exhibited increased characteristic path length and clustering coefficient, indicating reduced global integration and greater local segregation. Although small-world organization was preserved in two groups, there was less pronounced small-world architecture in older adults compared to younger adults, suggesting a shift toward more regularized, locally clustered networks and reduced long-range connections during dynamic stimuli. Participation coefficient values were higher in the somatomotor, frontoparietal, and default mode networks, and lower in the subcortical network, among older adults reflecting greater between-network integration in cortical networks but diminished subcortical coordination in aging. Five key nodes, two thalamic regions, hippocampus, and two insular regions, showed reduced centrality and efficiency in older adults during the negative movie, indicating weakened dominance of subcortical hubs under emotional salience condition. Right thalamic nodal properties were negatively associated with ERI and CFI and served as mediators in the relationship between age and emotional resilience. These findings suggest that reduced thalamic hub centrality may reflect adaptive recalibration of salience emotional processing, linking network reorganization to improved emotional resilience in aging. Key pointsO_LIOlder adults showed higher path length and clustering, suggesting reduced integration. C_LIO_LIReduced small-worldness reflects weaker balance of segregation and integration with age. C_LIO_LIOlder adults showed higher cortical but lower subcortical participation coefficients. C_LIO_LIKey nodes showed reduced centrality during negative stimuli, indicating weaker hubs. C_LIO_LIRight thalamus changes linked to resilience, mediating age-emotion relationships. C_LI

Cellular senescence is a stable cell-cycle arrest state associated with characteristic phenotypes, including enlarged cell morphology, altered secretory signaling, and pronounced lysosomal remodeling. Senescent cells commonly accumulate increased numbers of enlarged lysosomes with changes in acidity and degradative capacity, creating an opportunity for simple live-cell readouts of senescence-linked organelle remodeling. Here, I describe a live-cell lysosomal profiling protocol that uses LysoTracker Deep Red, an acidotropic fluorescent dye, to label and quantify acidic organelles in individual living cells as an indicator of senescence-associated lysosomal expansion. The method is demonstrated in IMR-90 human lung fibroblasts undergoing replicative senescence across serial passaging. The protocol details cell culture and passage tracking, LysoTracker staining, fluorescence imaging, and straightforward image-based quantification of lysosomal signal intensity and lysosome-enriched area per cell. As an optional validation step, senescence-associated {beta}-galactosidase staining is performed on parallel cultures to confirm senescent cell identity. Representative outcomes show increased LysoTracker signal and expanded lysosome-enriched regions in late-passage cultures compared to early-passage controls, consistent with lysosomal remodeling during senescence. This protocol is designed to be simple to adopt and can be adapted to other cell types or senescence-inducing stresses, providing a practical, quantitative complement to conventional endpoint assays. SUMMARYThis article presents a live-cell imaging protocol using LysoTracker Deep Red to quantify lysosomal remodeling as a marker of cellular senescence in IMR-90 human fibroblasts. We demonstrate quantitative lysosomal readouts derived from fluorescence imaging, including lysosome-enriched area and intensity measurements that can be summarized per cell and, when desired, as stitched-field, per-nucleus normalized metrics. Senescence status can be validated against senescence-associated {beta}-galactosidase (SA-{beta}-Gal) staining performed on parallel cultures. The method can be adapted to other cell types or senescence-inducing stresses and enables quantitative analysis of lysosomal remodeling during senescence.

{Delta}133p53 is a naturally occurring isoform of the human p53 protein that inhibits p53-mediated cellular senescence. We recently reported that transgenic expression of this senescence-inhibitory p53 isoform counteracts aging-associated pathological changes and extends lifespan in progeria model mice (heterozygous LmnaG609G/+). The anti-aging effect of {Delta}133p53 was attributed in part to reduced levels of the proinflammatory cytokine IL-6. To comprehensively profile {Delta}133p53-induced changes in cytokines and chemokines, we in this study performed a Luminex-based multiplex quantitative assay of mouse sera collected from transgenic {Delta}133p53-expressing LmnaG609G/+ mice and non-expressing controls. This assay not only confirmed the {Delta}133p53-mediated repression of IL-6 but also showed that {Delta}133p53 reduced the levels of CXCL1 (also known as KC), IL-1, and CXCL10 (also known as IP-10). Among these factors, we further characterized CXCL10, which has not previously been associated with progeria in mice or humans. Consistent with reduced serum CXCL10 levels, both young (15-week-old) and old (10-month-old) {Delta}133p53-expressing LmnaG609G/+ mice showed reduced Cxcl10 expression, compared with age-matched non-expressing controls, in the liver, spleen, and brain, major organs known to produce CXCL10. In naturally aged wild-type mice (2-year-old), Cxcl10 expression was also significantly repressed by transgenic {Delta}133p53 in the spleen and brain. Analysis of gene expression datasets from human tissues demonstrated an inverse association between CXCL10 and {Delta}133p53 levels, suggesting physiological relevance to human aging. This study defines CXCL10 as a proinflammatory chemokine elevated in both accelerated and natural aging and as a potential target of the anti-inflammatory activity of {Delta}133p53.

Declining spatial navigation abilities are a critical hallmark of aging, where the loss of spatial abilities precedes global cognitive impairment. While navigational decline is traditionally attributed to deficits in higher-order cognitive functions, emerging cognitive-motor frameworks suggest that age-related sensorimotor alterations play a significant, yet previously overlooked, role. Here, we investigate the coupling between locomotor integrity and navigation by combining an immersive virtual-reality path-integration paradigm with systematic manipulations of landmark availability and reliability, while recording gait kinematics alongside neural dynamics using high-density mobile-EEG from 30 young and 32 older adults. We demonstrate that older adults accumulate angular homing error more rapidly than younger adults, a deficit linked to altered gait dynamics. These age-dependent differences are reflected in increased mid-frontal theta activity, highlighting a robust coupling between gait-related sensorimotor alterations and decline in navigation. Older adults also exhibited increased reliance on visual landmarks, and particularly those with degraded gait, yet this compensatory reweighting of navigational cues remained less efficient and less precise than in younger adults. These findings highlight sensorimotor gait alterations as a central determinant of age-related navigation deficits, challenging the traditional separation of motor and cognitive domains and identifying locomotor integrity as a critical target for preserving spatial navigation abilities.

Time-restricted feeding (TRF) aligned with an organisms circadian rhythm has been shown to improve health, but its long-term effects on healthspan and lifespan in mammals, especially under normal dietary conditions, remain unclear. Here, we examined the impact of 12-hour (h) and 8h nightly TRF windows in male and female mice fed regular chow. TRF improved multiple health measures, including behavioral rhythmicity, body weight and composition, frailty, and disease onset. These effects were most pronounced in the 8h-TRF group, which exhibited voluntary caloric restriction in addition to time restriction. A composite Healthspan Index revealed that TRF extended healthspan in both sexes, though the benefits were more prolonged in females relative to their total lifespan. Median lifespan was significantly extended in males under 8h-TRF by 12%, whereas females showed no significant lifespan extension, highlighting sex-specific responses to TRF.

INTRODUCTIONHealthful dietary patterns may attenuate dementia risk by preserving cerebrovascular health. Prior work has focused on systemic arterial stiffness, but cerebrovascular measures may be more sensitive to neuroprotective effects of diet. We examined associations between Mediterranean diet adherence, prefrontal cortex (PFC) arterial elasticity, and cognition in older adults. METHODSParticipants were 198 older adults (58% female; mean age 65.6 years) from the Newcastle ACTIVate cohort. Mediterranean Diet (MedDiet) scores were derived from the Australian Eating Survey food frequency questionnaire. Pulse Relaxation Function (PReFx), an index of PFC arterial elasticity, was measured using pulse Diffuse Optical Tomography. Cognition was assessed with CANTAB and a cued task-switching paradigm. RESULTSHigher MedDiet was associated with higher PFC arterial elasticity. MedDiet was not associated with cognition, and PReFx did not mediate diet-cognition associations. DISCUSSIONGreater Mediterranean diet alignment was cross-sectionally associated with PFC arterial elasticity, suggesting a pathway through which diet may influence brain health in ageing.

ABSTRACT BACKGROUND: Recent studies consisting primarily of white participants have found lowered plasmalogen levels to be associated with lower cognitive function. We explore the association of blood plasmalogen levels with global cognition and brain imaging metrics in older African Americans. METHODS: Included in these cross-sectional analyses were participants in the Minority Aging Research Study (MARS) and the Rush Clinical Core without dementia, available serum lipid levels, and a concurrent cognitive function assessment. A plasmalogen biosynthesis value (PBV) was calculated for each participant utilizing five ratios of four key glycerophospholipids. A linear regression model of global cognition was constructed with PBV, adjusted for sex, age, education, total cholesterol, and body mass index. In participants with 3T MRI brain imaging, the association between PBV and white matter hyperintensities (WMH) was explored. RESULTS: Of the 298 participants, the mean age was 74.6 years, mean education was 15.6 years, and 84% were women. The median PBV was 0.42 (interquartile range: 0.22 to 1.14). A unit higher in PBV was suggestively associated with a 0.17 {beta}-unit higher cognitive z-score (SE =0.09, p = 0.06). In 254 participants with MRI data, an increase in log10 SD of PBV suggested the less white matter hyperintensities (estimate = -0.20, SE = 0.12, p = 0.08). DISCUSSION: In older African Americans, higher PBV was associated with higher level of global cognition, and potentially lower levels of brain white matter hyperintensities. Larger studies are needed in additional cohorts to determine if PBV is associated with annual rate of change in cognitive function.