Aging

Background: Advances in antiretroviral therapy (ART) have transformed human immunodeficiency virus (HIV) infection into a manageable chronic condition. However, people with HIV (PWH) face an increased burden of age-related non-AIDS-defining illnesses. Epigenetic age (EA) and epigenetic age acceleration (EAA), based on DNA methylation, have emerged as objective indicators of biological aging. Although studies in Western countries suggest that EAA levels are elevated in PWH and may decline after ART initiation, evidence in the Japanese population remains scarce. This study aims to characterize EA and EAA in Japanese PWH and to evaluate their associations with the duration of ART, cumulative exposure to specific drug classes, frailty, lifestyle factors, and immunological, metabolic, and inflammatory markers. Methods: This single-center, cross-sectional study involves 100 adult Japanese males with HIV who have received ART for at least 12 months. EA and EAA will be calculated using whole-blood DNA methylation data generated using the Illumina Infinium MethylationEPIC v2.0 BeadChip array and epigenetic clocks developed on Japanese populations. Linear regression models will be used to evaluate the associations between EAA and the factors collected from medical records, laboratory tests, self-administered questionnaires, and comorbidities. Discussion: This study provides baseline data for future longitudinal and comparative studies. The integration of clinical, questionnaire, and omics data facilitates the exploration of biological mechanisms underlying aging in this population. The limitations include the cross-sectional design, which precludes causal inference and the lack of a control group.

Hutchinson-Gilford Progeria Syndrome (HGPS) is a rare genetic condition characterized by features of accelerated aging, with a life expectancy of less than two decades. HGPS is commonly caused by a point mutation in the LMNA gene which codes for lamin A, a vital component of the nuclear lamina. The HGPS mutation activates a cryptic splice site and leads to production of a truncated, farnesylated form of lamin A referred to as "progerin." Progerin is also produced in small amounts in healthy individuals and has been implicated in normal aging. HGPS is associated with an accumulation of genomic DNA double-strand breaks (DSBs), and alterations in DSB repair. DSB repair in mammalian cells normally occurs by either homologous recombination (HR), an accurate, templated form of repair, or by DNA end-joining (EJ), a non-templated rejoining of DNA ends. EJ is error-prone, although a portion of EJ events occurs precisely with no alteration to joined sequences. Previously, we reported that over-expression of progerin increased EJ relative to HR and decreased the precision of EJ. In our current work, we designed a novel model experimental system using derivatives of thymidine kinase (tk)-deficient mouse fibroblasts and incorporating a loss-of-function assay to further explore progerins impact on EJ. We established cell lines containing an integrated copy of a functional herpes tk gene with an embedded recognition site for endonuclease I-SceI. We examined EJ at the nucleotide level following induction of a DSB within the tk gene by expression of I-SceI and subsequent selection for cells that lost tk gene function. Comparison of EJ products recovered from cells expressing progerin versus from cells not expressing progerin revealed that progerin expression provoked larger DNA deletions associated with DSB repair as well as recovery of multiple repair products from individual cells, suggesting progerin impedes re-joining of DNA ends.

Individuals with Down syndrome (DS) exhibit accelerated biological aging and unique patterns in disease prevalence. However, empirical characterizations of relative risk and age at onset of disease in this population are not common. Here we aimed to quantify the difference in risk and timing of age-related conditions between individuals with DS when compared to typically developing (TD) matched controls. We used semiparametric Cox proportional hazards models and Restricted Mean Event-Free Age (RMEA) to estimate differences in risk and approximate average age at onset of cataracts, cognitive decline, death, menopause, and osteoporosis. Individuals with DS were at higher risk of all age-related conditions or events and experienced these events at younger ages, excluding menopause. We observed a 24.5-fold higher risk of cognitive decline in individuals with DS (p<0.001), and between a 2- and 4-fold higher risk of the other age-related events or conditions (p<0.01). Cognitive decline and death occurred more than 14 years earlier in individuals with DS and were more likely to co-occur (p<0.001) compared to in TD individuals. These findings have important implications for tailored screening and prevention efforts in aging individuals with DS, as this population experiences a distinct cadence of age-related events.

Recent epidemiological studies suggest poor hydration is a modifiable risk factor for aging-related chronic disease. We tested whether serum sodium was associated with accelerated biological aging. We analyzed data from 363,286 adults (18-80 years) from 20 years of electronic medical records from a large healthcare system, as well as 24,611 adults (18-80 years) from National Health and Nutrition Examination Survey (NHANES) continuous (1999-2018). Seven key biomarkers were used to calculate biological age (BA) using the Klemera and Doubal method. We then reran the calculation using only the four variables with highest correlation with age as a robustness check. In both models, there was a significant linear association between age adjusted serum sodium and advanced biological aging, especially in the young cohorts. In the 7-variable model, in the Leumit dataset, the males in the highest sodium level versus the lowest, had a biological age that was 0.88 (95% CI 0.68-1.08) years accelerated and for females 2.32 (2.14-2.51) years. In NHANES dataset biological age of males at the highest sodium level was 1.92 (0.98-2.87) years accelerated as compared to those in the lowest sodium group. For females, the largest difference was for those 41-50 (1 year, .30-1.79). Increased serum sodium in the normal range is associated with accelerated biological aging in the general population, especially among people aged 18-50. Intervention studies are needed to confirm the link between hydration and biological aging.

BackgroundDNA methylation-based biomarkers have enabled robust estimation of biological age across tissues, and longitudinally trained measures such as DunedinPACE provide estimates of the pace of aging from blood methylomes. However, longitudinal methylation data are often unavailable, particularly for minimally invasive tissues such as buccal mucosa. Here, we developed a pseudo-longitudinal framework to estimate a buccal mucosa-derived PACE-like aging-rate score from cross-sectional methylome data. MethodsWe used a buccal biological age estimator as an internal pseudo-time axis. Methylation beta-values were transformed to M-values, and CpG-specific smooth functions of biological age were fitted in cross-validation. Local derivatives of these functions were used to project each individuals buccal methylome forward by a small time step. The projected methylome was converted back to beta-values, biological age was recalculated, and the change in biological age per unit time was defined as a pseudo-aging velocity. This raw velocity was transformed to a non-negative PACE-like score centered at 1.0. We then trained cross-fitted models to predict the derived score from buccal CpG methylation profiles. ResultsIn 151 individuals, the proposed score was reproducibly predicted from buccal methylomes in out-of-fold analysis, with a Pearson correlation of 0.706 and Spearman correlation of 0.710 between observed and predicted PACE-like scores. Sensitivity analyses across CpG selection size and regression models showed broadly consistent performance. In contrast, the proposed buccal PACE-like score showed only modest association with measured DunedinPACE, and alternative attempts to reconstruct DunedinPACE from buccal methylomes, including supervised proxy modeling and buccal-to-blood CpG imputation, showed limited sample-level performance. ConclusionsThese results support the feasibility of deriving a tissue-specific PACE-like aging-rate score from cross-sectional buccal methylome data by treating biological age as a pseudo-time axis. The proposed score should not be interpreted as a replacement for blood-derived DunedinPACE, but rather as an exploratory buccal methylome dynamics index that may capture tissue-specific aging-related variation.

Accurate epigenetic age prediction from DNA methylation profiles is intrinsically high-dimensional, creating a need for parsimonious models that preserve predictive performance while reducing the number of assayed cytosine-phosphate-guanine (CpG) loci. This study introduces MOSurvivor, a population-based multi-objective search framework that jointly optimizes a weight-threshold CpG selector and eight XGBoost hyperparameters. Experiments used the GSE40279 whole-blood cohort (656 individuals profiled on the Illumina HumanMethylation450 platform). After retaining 1,000 age-correlated CpGs, five strategies were evaluated on the same 30 seeded 80:20 train/test splits: fixed-parameter XGBoost using all 1,000 CpGs, random search, a genetic algorithm, particle swarm optimization, and MOSurvivor. Internal fitness was estimated using three-fold cross-validation on each training set. Across the 30 held-out test sets, MOSurvivor achieved a mean absolute error (MAE) of 4.149 {+/-} 0.300 years, root mean squared error of 5.545 {+/-} 0.392 years, and R2 of 0.855{+/-} 0.027 while retaining 211.6 {+/-} 54.8 CpGs. Relative to full-feature XGBoost (MAE 4.095 {+/-} 0.285 years), MOSurvivor reduced the feature set by 78.8% at an MAE increase of only 0.054 years (1.3%). Paired Wilcoxon tests found no significant accuracy difference between MOSurvivor and any comparator (all unadjusted p > 0.05; all Holm-adjusted p [&ge;] 0.476). The most recurrent locus, cg16867657, appeared in 29 runs, whereas mean pairwise Jaccard similarity was 0.124, indicating a small stable core embedded in multiple near-equivalent feature subsets. MOSurvivor thus offers a competitive accuracy-parsimony trade-off rather than superior absolute accuracy. External validation and leakage-free nested feature preselection remain necessary before biological or clinical translation. Keywords: epigenetic clock, DNA methylation, feature selection, multi-objective optimization, XGBoost, metaheuristics, biological aging.

Introduction: HIV and childhood maltreatment (CM) are both chronic stressors that disproportionately affect women, with each contributing to accelerated biological aging. Whether biological aging markers are convergent and associate with HIV and CM is unclear. Methods: We studied 238 women (122 with HIV), characterised for CM severity, and assessed biological aging using absolute telomere length (aTL), mitochondrial DNA copy number (mtDNAcn), magnetic resonance imaging-based brain-predicted age difference (MRI-BPAD), and DNA methylation age (DNAmAge) clocks. CM was measured with the Childhood Trauma Questionnaire-Short Form total score. We examined intercorrelations among biological aging markers to assess convergence and conducted linear regression models to test moderation by HIV status and CM severity. Results: PWH had shorter aTL, lower MRI-BPAD, and higher Horvath age acceleration (HorvathAA), HannumAA, PhenoAA, and extrinsic epigenetic age acceleration (EEAA). CM had limited associations with biological aging markers. Absolute TL correlated weakly with mtDNAcn (p = 0.36), PhenoAA (p = -0.18), and EEAA (p = -0.18), while MRI-BPAD correlated weakly with PhenoAA (r = 0.20). DNAmAge clocks were moderately to strongly intercorrelated (r = 0.35 - 0.93). No robust two- or three-way moderation effects were observed after false discovery rate correction. Conclusion: Our findings support a multidimensional pattern of biological aging, with substantial convergence among epigenetic aging measures but limited relationships across different markers, largely independent of HIV status and CM severity. Longitudinal approaches are needed to clarify how distinct biological aging markers relate to one another and to health outcomes over time in vulnerable populations.

Cellular senescence contributes to the progression of many age related musculoskeletal diseases. Cellular senescence is a biological state that arises from replicative exhaustion and various cellular stressors, including elevated oxidative stress, mitochondrial dysfunction, mechanical overload, and chronic exposure to pro-inflammatory cytokines and proteases. Although senolytic agents show promise for eliminating senescent cells, their translation has been hindered by the lack of physiologically relevant and scalable in vitro screening methods. In the present study, we developed a standardized, physiologically relevant senescence-induction model and validated a metabolic activity assay as a rapid, scalable method for screening senolytic compounds. We used primary human intervertebral disc cells (IVD) as an example, but the workflow applies to many other cell types. To mimic inflammatory and oxidative stress, we used a combination of TLR-2 activation (Pam2CSK4) and tert-butyl hydroperoxide (tBHP), a potent ROS generator. Senescence induction was validated by quantifying {beta}-galactosidase fluorescence intensity, {beta}-gal enzymatic activity, and the expression of the p16 senescence marker across 3 IVD cell types: nucleus pulposus (NP), inner annulus fibrosus (iAF), and outer annulus fibrosus (oAF) cells. The combined Pam2CSK4 + tBHP exposure generated a robust senescent phenotype across all 3 IVD cell types, with oAF cells exhibiting the strongest increases in {beta}-gal fluorescence, {beta}-gal enzymatic activity, and p16 expression. We then used oAF cells to evaluate if the metabolic activity assay (Alamar Blue) could be used to determine both cytotoxicity of senolytic drugs in non-senescent cells and senolytic activity in a mixed population of senescent and non-senescent cells. We validate the method by comparing metabolic activity results with {beta}-gal enzymatic activity and p16 expression in induced and noninduced cells following exposure to three known senolytics (o-Vanillin, RG-7112, and ABT-199). The metabolic activity assay reliably identified a therapeutic window in which the three senolytics were non-toxic to non-senescent cells while selectively reducing metabolic activity in a mixed population of senescent and non-senescent cells. The reductions in metabolic activity in the mixed population correlated with decreases in SA {beta}-gal enzymatic activity and p16 expression, validating metabolic activity as a sensitive and scalable senolytic readout.

Osteocytes are long-lived cells that play a central role in bone homeostasis, yet age-related changes in their functional states remain poorly understood, particularly because skeletal aging involves multiple processes beyond cellular senescence. We generated an osteocyte-specific MepeCre mouse line and combined osteocyte ablation in young and middle-aged mice with skeletal phenotyping, single-cell transcriptomics, and senolytic treatment. MepeCre-driven recombination was largely confined to osteocytes, with minimal off-target activity. Osteocyte ablation increased bone mass at both ages, indicating that osteocytes constrain bone accrual as part of their role in skeletal homeostasis. However, the accompanying remodeling changes differed with age: enhanced osteoblast activity predominated in young mice, whereas reduced osteoclast-mediated bone resorption predominated in middle-aged mice. Single-cell transcriptomics revealed distinct osteocyte subpopulations whose relative abundance shifted with age, from a predominantly matrix-enriched state in young mice to an expanded aging-transitional state in middle-aged mice. Although this state showed partial enrichment of senescence-associated transcriptional signatures, senolytic treatment failed to recapitulate the increase in bone mass induced by osteocyte ablation. Osteocyte therefore regulate bone mass through age-dependent mechanisms that coincide with shifts in osteocyte-state composition. These changes emerge by middle age and may contribute to early remodeling imbalance before overt cellular senescence during skeletal aging. Graphical AbstractGraphical summary of the findings of this study. AA, amino acids; NA, nucleic acid; UA, uric acid; TCA, tricarboxylic acid.

Aging is associated with impaired skin wound healing, but the molecular mechanisms underlying this decline remain incompletely understood. In particular, how aging affects the temporal regulation of mechanosensitive signaling during tissue repair is poorly understood. In this study, we investigated age-associated changes in cutaneous wound healing, with a focus on Yes-associated protein (YAP)-associated mechanosensitive responses, and examined whether ICE mice, an inducible model of epigenetic aging, reproduce age-associated impairment in wound repair. Splinted full-thickness excisional wounds were generated in young and naturally aged mice, and wound closure, gene expression, and active YAP were evaluated over time. Aged mice exhibited delayed wound closure, particularly during the mid-to-late phases of repair. Expression of the fibrosis-related genes Tgfb1, Col1a1, and Col3a1, and the YAP-associated genes Ctgf, Cyr61, and Arhgap18 did not differ significantly between young and aged wounds at the examined time points. In contrast, Ankrd1 was selectively elevated in aged wounds at postoperative day 14. Active YAP immunofluorescence showed age-associated differences in staining patterns during wound healing, indicating altered regulation of mechanosensitive signaling with aging. Furthermore, ICE mice exhibited delayed wound closure compared with Cre control mice, reproducing a major functional feature observed in naturally aged mice. These findings suggest that age-associated impairment of wound healing is characterized not by uniform activation or suppression of YAP-related signaling, but by altered temporal regulation of mechanosensitive responses together with selective Ankrd1 elevation. ICE mice could provide a useful experimental model for investigating age-associated defects in cutaneous wound healing.

Fasting-based dietary interventions are conserved regulators of aging that extend lifespan across species, including Caenorhabditis elegans. However, fasting studies in C. elegans are sensitive to experimental variables that can independently influence lifespan and health, including FUdR, antibiotic treatment, germline-less mutants, and the use of UV- or heat-killed bacteria. FUdR can alter lifespan, age-associated pathology, and stress responses, while antibiotics used to prevent bacterial growth during fasting may directly affect worm physiology. To minimize these confounding factors, we developed a simple adult-onset intermittent fasting paradigm that does not require FUdR, antibiotics, or bacterial killing. Wild-type worms were subjected to daily fasting periods of 5 h, 6 h, or 18 h until day 10 of adulthood and compared with continuously fed controls. Daily intermittent fasting robustly extended lifespan by 24-57%, demonstrating that repeated fasting windows during adulthood are sufficient to promote longevity under minimally confounded conditions. These findings establish a straightforward and experimentally tractable intermittent fasting paradigm for C. elegans and underscore the importance of limiting pharmacological and microbial conditions in dietary-intervention experiments.

Valid animal models are needed to evaluate how age-related changes in kidney function influence healthspan. Aging marmosets frequently develop renal insufficiency with anemia and exhibit reductions in body mass and metabolic rate. However, it remains unclear which age-related changes predict survival and which thresholds indicate increased mortality risk. We prospectively evaluated age, body composition, resting energy expenditure, hematology, and blood chemistry as predictors of 3-year survival in female and male marmosets (n = 66), 2-16 years of age. Objectives were to identify prognostic markers, define high-risk thresholds, and to develop and test a composite risk-factor scale for mortality screening in captivity. A 10-variable model showed the best predictive performance in multivariable Cox proportional hazards modeling, and was retained for further analysis (concordance = 0.881, p < 0.001). ROC curves using Youdens Index and AUC identified high-risk thresholds for predictors in the multivariable model, and threshold-defined categories were evaluated by Kaplan-Meier survival analysis. The 10 binary risk-factors were combined into a composite scale scored from 0 to 10 and tested with Cox regression. The scale explained approximately 42% of variance in survival and each additional risk factor increased mortality risk 1.75-fold (95% CI: 1.43-2.14, p < 0.001). Marmosets with [&ge;]7 risk factors exhibited a 19-month reduction in survival, and this high-risk threshold predicted 3-year survival with 89.4% accuracy. Results support the scale as a screening tool for mortality risk and highlight the high prevalence of age-associated renal disease and anemia in marmosets.

Aging is a multidimensional process, yet most aging models reduce it to a single score to estimate biological aging and predict health outcomes, disease risk, or mortality. Here, we introduce PUMA (Phenotypic Unsupervised Model of Aging), a framework that characterizes aging through multiple phenotypic dimensions. Applying PUMA to more than 1,000 traits spanning behavioral, psychological, social, physical, environmental, and biomedical domains in over 150,000 individuals from the Lifelines cohort, we identified seven distinct phenotypic aging dimensions. These dimensions were significantly associated with the future incidence of major age-related diseases--including cancer, diabetes, COPD, heart failure, stroke, and Parkinsons disease-- demonstrating the potential of PUMA to stratify individuals by disease risk and identify phenotypic domains for targeted intervention. Notably, dimensions reflecting psychosocial factors, particularly cumulative life stress, predicted disease risk as strongly as, or more strongly than, traditional biomedical risk factors, highlighting the importance of psychological and social influences in aging and disease risk. The observation that phenotypic aging dimensions are differentially associated with the future risk of age-related diseases supports a multidimensional model of aging, indicating that aging is not a single uniform process. Because PUMA relies on accessible phenotypic data, it provides an interpretable framework for disease risk stratification and targeted preventive strategies.

The aim of this study was to compare three methods for estimating biological age (BA) based on heart rate variability (HRV) indices recorded in the supine position: multiple linear regression (MLR), MLR corrected for regression-to-the-mean bias using the Dubina method (1984), and the Klemera-Doubal Method (KDM, 2006). A total of 343 subjects were examined (193 women and 150 men aged 20-90 years); nine time- and frequency-domain HRV indices were analyzed (NN, lnSDNN, lnRMSSD, lnVLF, lnLF, lnHF, VLF%, LF%, HF%). The association between HRV indices and chronological age was substantially in women and men (p<0.01). KDM produced the lowest estimation error (MAE=4.34 years in women, 3.67 years in men), whereas uncorrected MLR produced the largest error (MAE=6.57 and 7.47 years, respectively); the Dubina correction substantially improved MLR accuracy (MAE=4.22 and 4.82 years) but relied directly on actual chronological age, which limits its independent diagnostic value. The strengths and limitations of each method and recommendations for their application are discussed.

Cellular senescence has emerged as a key contributor to age-related skeletal deterioration; however, the defining characteristics of senescent osteoblasts remain incompletely understood, hindering efforts to identify the cellular mechanisms that drive age-associated bone loss and potential therapeutic targets. Here, we compared doxorubicin- and hydrogen peroxide-induced senescence and established a robust in vitro osteoblast model that enables the stable maintenance of stress-induced premature senescence. Doxorubicin-treated MC3T3-E1 cells exhibited persistent growth arrest, a pronounced senescence-associated secretory phenotype (SASP), and impaired osteogenic function accompanied by marked mitochondrial dysfunction, including reduced respiratory capacity and altered mitochondrial morphology. Transcriptomic comparison with aged murine bone revealed a partial overlap with in vivo aging-associated gene expression signatures, particularly among genes involved in extracellular matrix organization and skeletal development, supporting the physiological relevance of the model. Importantly, key features of senescence, including the senescence-associated mitochondrial phenotype and impaired osteogenic capacity, were recapitulated in primary human osteoblasts. Collectively, these findings establish a robust model of stress-induced osteoblast senescence and demonstrate that senescent osteoblasts exhibit mitochondrial dysfunction, impaired osteogenic capacity, and molecular features that resemble aspects of skeletal aging.

The ovary is both one of the earliest organs to functionally age in the body, with declines emerging well before reproductive failure and contributing to systemic aging. Since ovarian function depends on tightly regulated hormonal and inflammatory cycles, even subtle disruptions can confound aging-related phenotypes. Tamoxifen-inducible Cre systems are widely used to study ovarian biology, however, tamoxifen is a selective estrogen receptor modulator capable of disturbing ovarian physiology. This introduces a critical and often overlooked concern that tamoxifen-based models may produce lasting effects that obscure true biological signals, particularly in ovarian aging studies. To address this, we tested the hypothesis that tamoxifen induces transient physiological disruption without altering long-term transcriptional outcomes. Female mice were treated with tamoxifen or vehicle at 3 months of age, and estrous cyclicity was monitored longitudinally by vaginal cytology at 3 days, 2 months, 3 months, 6 months, and 12 months post-induction. Ovaries were collected at young (6 months) and aged (12 months) time points for bulk RNA sequencing, followed by differential gene expression and pathway-level analyses. We found that tamoxifen treatment disrupted estrous cyclicity shortly after administration, confirming short term physiological effects. However, normal cycling was restored by 3 months post-treatment, indicating recovery of ovarian function. At the transcriptional level, minimal differences were observed between tamoxifen and vehicle treated groups at both young and aged time points. In contrast, aging-associated transcriptional programs were conserved across treatment conditions with shared alterations in pathways related to extracellular matrix remodeling, senescence, and cellular homeostasis. Together these findings demonstrated that while tamoxifen disturbs ovarian physiology in the short term, it does not produce lasting transcriptional effects or aging associated phenotypes. These results resolve a critical methodological concern and provide validation for the use of tamoxifen-inducible systems in ovarian research, supporting their application in studies of reproductive aging and systemic female health when proper controls are integrated into study design.

Lifecourse physical resilience is defined by the ability to maintain abilities across multiple domains of physical performance. While the importance of physical resilience in functional independence and mobility disability is clear, studies investigating metabolomic signatures of physical resilience are lacking. Here, we performed untargeted metabolomics on serum samples from a community-based cohort of 237 individuals followed over 28 years, and applied spectral data mining tools to map identified metabolites to health phenotypes from public repositories. We identified metabolites across multiple chemical classes, including acylcarnitines, glutamine conjugates, and phosphocholines, that were differentially associated with physical resilience status. Notably, medium-chain acylcarnitines negatively associated with physical resilience were more frequently observed in disease phenotypes than in healthy individuals. Kynurenine, a tryptophan metabolite linked to age-related functional decline, increased more steeply with age in individuals with low physical resilience. We also found that metabolites of the antihypertensive drug verapamil were associated with physical resilience in a metabolism-dependent manner, differing between oxidative and glucuronidated forms. Together, these metabolic signatures offer a resource for identifying biochemical pathways and biomarkers relevant to physical resilience for healthy aging.

Apigenin is an abundant, bioactive phytochemical with reported therapeutic potential and neuroprotective effects in a variety of age-related disease models. However, the extent to which apigenin may promote healthspan and protect against neurodegeneration-associated proteotoxicity has not been thoroughly investigated, and the biological processes/mechanisms that underlie its protective effects remain unclear. To determine if apigenin increases healthspan, we performed lifespan assays in conjunction with measures of aging-relevant physiological function in wild-type C. elegans. We found that chronic exposure to apigenin extended median lifespan and improved multiple readouts of healthspan, including pharyngeal pumping, locomotor activity, and age-related macromolecular damage accumulation. Additional analyses of transgenic reporter strains and transcriptomic profiling (RNA-seq) indicated that apigenin primarily modulated redox-sensitive stress signaling and pathways associated with cellular homeostasis in aging animals. Finally, in transgenic C. elegans strains expressing the pathological Alzheimer's disease-associated proteins amyloid-beta or tau, we found that apigenin had similar beneficial effects on lifespan, healthspan, and proteotoxicity-associated functional impairments. Together, our results support apigenin as a potential healthspan-promoting intervention that acts in part through reductions in oxidative stress-associated signaling, with beneficial effects that extend to models of Alzheimer's disease-associated proteotoxicity.

Aging is associated with proteome remodelling and progressive accumulation of insoluble proteins. Identifying age-enriched proteins that undergo aggregation and evaluating compounds capable of modulating their behaviour may provide insights into interventions that promote healthy aging. Here, we report a proteome-guided strategy to identify age-associated aggregation-prone proteins and evaluate phytochemicals targeting conserved proteins in Caenorhabditis elegans. We identified proteins whose abundance increased more than four-fold in aged worms compared with young worms, many of which also accumulated in the age-associated insoluble proteome, and subsequently identified their human orthologs for comparative analysis. Based on biological relevance, structural conservation, and availability of high-confidence structural models, glutamine-fructose-6-phosphate aminotransferase-2 (GFAT-2) was selected for molecular docking. Screening of fifteen phytochemicals against C. elegans GFAT-2 and its human ortholog GFPT1 identified quercetin as the strongest predicted binder, exhibiting conserved interactions with both proteins. However, treatment of worms with quercetin did not significantly alter global protein insolubility during aging. This may reflect its ability to modulate inappropriate protein-protein interactions without substantially affecting the overall aggregation burden. These findings underscore the need for experimental validation of favourable in silico docking predictions. More broadly, this study provides a proteome-guided framework for prioritizing age-associated aggregation-prone proteins as candidate therapeutic targets for preserving proteostasis during aging.

SIRT6 is a NAD+-dependent sirtuin that plays central roles in chromatin regulation, DNA repair, telomere maintenance, metabolic homeostasis, and inflammatory control. Although SIRT6 have long been implicated in aging because of its association with several hallmarks of aging, the available evidence remains largely context-dependent and mechanistic, limiting the interpretation of SIRT6 as a robust and evolutionarily conserved biomarker of aging. To comprehensively investigate the role of SIRT6 as an aging biomarker, we established SIRT6.db, a multi-species transcriptomic resource that integrates SIRT6-targeted perturbation experiments across diverse biological systems and organisms form all available SIRT6-related publications collected via a large-scale textual analysis of the SIRT6 literature using topic modeling. Based on this database, we identified both species-specific and evolutionarily conserved transcriptional and functional signatures associated with SIRT6 perturbation and established their relevance to hallmarks of aging. We showed that SIRT6 expression is generally stable during normal aging, but becomes dysregulated in Alzheimer's disease in cell type and stage-specific manner, highlighting the context dependence of its potential as a transcriptomic biomarker of aging.