Aging

Sepsis can lead to acute respiratory distress syndrome (ARDS) and is associated with a high mortality rate. This study investigated cellular senescence-related genes in sepsis and sepsis-induced ARDS to identify novel biomarkers. Using bioinformatics analyses including WGCNA and machine learning on public datasets, six hub genes (NFIL3, GARS, PIGM, DHRS4L2, CLIP4, LY86) were identified. These genes showed strong diagnostic value and were associated with immune cell infiltration and key pathways. Validation in lipopolysaccharide (LPS)-stimulated neutrophils showed significant upregulation of NFIL3. The findings highlight the role of cellular senescence in pathogenesis and identify promising therapeutic targets for sepsis-induced ARDS.

BackgroundDNA methylation-based biomarkers have been widely used to predict biological age; however, most blood-derived data have been used in most existing models, and whether cheek mucosa can serve as an alternative indicator for methylation-based estimation of aging-related and clinical phenotypes is unclear. MethodsDNA methylation profiles from cheek mucosa and whole blood of 186 Japanese adults were analyzed using Illumina Infinium Methylation Screening Array (MSA). Models were constructed to predict chronological age, phenotypic age, and clinical laboratory biomarkers from cheek mucosa- and blood-derived methylation data. In addition to applying the ordinary elastic net method, a two-stage residual learning method incorporating existing blood-based epigenetic clocks was applied for more accurate prediction of biological age. Sex-stratified analyses and comparisons of selected CpG features across sexes and tissues were performed. ResultsCheek mucosa-derived MSA methylation data enabled accurate prediction of chronological age (R = 0.965) and phenotypic age (R = 0.964) using the two-stage method. The performance gain achieved by the two-stage approach was greater for phenotypic age than for chronological age. Multiple clinical laboratory biomarkers could be predicted using cheek mucosa-derived methylation data, particularly after sex stratification, including inflammatory, metabolic, thyroid-related, and sex hormone-related markers. Most biomarkers that could be predicted using blood-derived methylation data were also predicted using cheek mucosa-derived methylation data. However, the CpG sites selected for prediction showed minimal overlap across sexes and tissues despite overlap in the corresponding predictable phenotypes. ConclusionsCheek mucosa-derived DNA methylation profiles measured using the MSA can predict chronological age, phenotypic age, and multiple clinically relevant laboratory biomarkers, supporting the utility of cheek mucosa as a less invasive alternative for methylation-based assessment of biological aging and systemic physiological state.

Aging in the immune system results in increased susceptibility to infections, exacerbated autoimmunity, and reduced responsiveness to vaccines. However, there are no current established interventions for immune aging. Ketogenic diets and fasting have been researched as interventions against other aspects of aging and age-related diseases, and they work in part by increasing circulating levels of ketone bodies, which have anti-inflammatory properties and can boost T cell function. Exogenous ketones, such as ketone esters, are currently being studied as a more accessible approach to obtain the benefits of ketone bodies through direct supplementation. Here, we investigated whether ketone ester supplementation improves immune function during aging. Aged (19-month-old) C57BL/6JN mice were given a diet supplemented with the ketone ester or a control diet for 15 weeks. We found that the ketone ester diet decreased activation of B cells, especially age-associated B cells, in the spleen. In spite of this decrease in activation, mice on the ketone ester diet showed no impairment in antibody production after nitrophenyl-ovalbumin immunization. The ketone ester diet also inhibited glucose dependence and translation of age-associated B cells, likely through inhibition of mTOR signaling via ketone bodies. Our study elucidates the effect of ketone esters on B cells in the context of aging and unveils a new immunoregulatory role of ketone bodies on B cells.

Nucleos(t)ide reverse transcriptase inhibitors (NRTIs) used for HIV treatment and pre-exposure prophylaxis have been proposed as gerotherapeutics based on their capacity to suppress age-associated retrotransposon activity. However, evidence in humans is currently lacking. Here we evaluated DNA methylation-based measures of biological aging in healthy people without HIV (aged 18-50) using samples from two separate randomized, directly observed dosing pharmacokinetic studies of FDA-approved NRTI regimens containing emtricitabine-tenofovir-alafenamide (FTC/TAF;200 mg/25 mg) or FTC-tenofovir-disoproxil fumarate (FTC/TDF; 200 mg/300 mg) for 12 weeks. In the FTC/TAF study (N=36), epigenetic aging measures based on DNA methylation (DNAm) profiling decreased over follow-up, including DunedinPACE (-0.061, p=0.019) and PhenoAge (-6.33, p=0.008), with concordant reductions (p<0.05) across additional systems-specific epigenetic clocks including those estimating brain aging. DNAm-based proxies of inflammatory biomarkers also declined, with significant reductions in epigenetic IL-6 (-0.058, p=0.029) and a trend toward reduced C-reactive protein (-0.231, p=0.059). In contrast, the FTC/TDF study (N=43) showed no significant changes across epigenetic clocks and proxies. These findings are consistent with TAFs more favorable cellular pharmacology compared with TDF and support gerotherapeutic effects of FTC/TAF. Prospective placebo-controlled studies are warranted that integrate clinical pharmacology, direct transposable element readouts, and prespecified geroscience and DNA methylation-based aging endpoints.

The relationship between age-related genetic factors and health conditions has become a pivotal focus in aging research, particularly as the World Health Organization (WHO) delineates the leading global causes of mortality. However, the direct impact of age-related genes on the leading cause of death remains poorly understood. To investigate this gene-aging relationship, we analyzed protein-protein interactions using gene set enrichment analysis (GSEA) of a set of 307 age-related genes previously curated. The results indicated significant associations with 113 diverse disease categories, while adhering to a stringent false discovery rate (FDR) threshold of less than 1 x 10-5. Due to the difficulties in aligning the disease categories with WHOs leading causes of death, we reclassified the WHO categories using the more precise nomenclature specified in the 11th Revision of the International Classification of Diseases (ICD-11). The age-related genes account for the leading causes of death, with the exceptions being two infectious communicable diseases, tuberculosis and COVID-19. They impact the cardiovascular system, brain, lungs, and the whole body, while this study could not identify death by aging, which is not a well-defined medical cause of death. Furthermore, we identified a set of 15 recurring genes shared among multiple diseases, including TNF, AKT1, IL6, CDK2A, APOE, and TP53. This gene set was enriched for several disease categories, including cancer, inflammatory diseases, metabolic disorders, and neurodegenerative diseases. Additionally, it shows significant enrichment in various biological categories, with the regulation of nitric oxide activity being the most prominent; other enriched categories include the regulation of microRNA, lipid and carbohydrate metabolism, smooth muscle cell proliferation, insulin signaling, and phosphatidylinositol-3 kinase (PI3K) signaling. The findings suggest that the recurring genes act as pleiotropic hubs, influencing multiple leading causes of death, while other genes are more specific to each disease category.

BackgroundHemoglobin A1c (HbA1c), an important diagnostic biomarker for type 2 diabetes (T2D), is also associated with aging, cognitive performance, and mortality. To identify epistatic interactions, we assessed 133 known gene variants associated with HbA1c among 3,778 non-diabetic subjects of European ancestry in the Long Life Family Study (LLFS). MethodsWe applied Bayesian Imputation Based Association Mapping (BIMBAM) to identify significant pairwise epistatic interactions among genetic variants that were previously shown to be associated with levels of HbA1c. To take into account confounding effects, we adjusted age, sex, field centers, body mass index (BMI), and genetic principal components (PCs). ResultsThis analysis yielded seven pairs with log10(BF)>10; of those, six pairs were confirmed using a full-term mixed regression model. Specifically, these included significant interactions of HK1-rs17476364 with variants in GCK (rs2971670, rs4607517) or G6PC2 (rs560887), as well as between HK1-rs16926246 and the same variants (P values for each term [&le;] 7.14x10-3). All epistatic interactions between HK1 and GCK, and between HK1 and G6PC2 were replicated in two large independent studies (namely, Framingham Offspring Study, P < 0.05; Health and Retirement Study, P < 0.05). ConclusionThe present study revealed that HK1 and GCK interact to contribute to regulating levels of HbA1c and are likely to be involved in molecular mechanisms underlying healthy aging processes.

ObjectivesPrior studies have shown that cyclin D1 regulates diverse aspects of liver metabolism during cell cycle progression. Interestingly, this protein is induced in hepatocytes by feeding, but its function in modulating hepatic postprandial physiology is poorly characterized. The aim of this study was to evaluate the contribution of cyclin D1 to the hepatic response to feeding and to gain insight into its potential non-proliferative roles in other conditions. MethodsMice with or without hepatocyte cyclin D1 (D1fl/fl or D1{Delta}Hep) were fasted and refed a high-carbohydrate diet. Mouse and human liver in the setting of aging and MASLD were analyzed. The C. elegans model was used to evaluate the role of cyclin D1 (CYD-1) in response to overnutrition. ResultsCyclin D1 regulated hepatic gene networks involved in glucose and lipid metabolism, protein synthesis, immune response, and other pathways after feeding. Induction of acute phase response proteins was markedly inhibited in D1{Delta}Hep mice, which was associated with corresponding changes in histone acetylation on key genes. In aged liver, hepatocyte cyclin D1 was induced without associated proliferation; this was markedly pronounced in progeroid Ercc1-deficient mice. Cyclin D1 was upregulated in MASLD and diminished with successful treatment. CYD-1 was induced by overnutrition in the intestine of Caenorhabditis elegans (which performs metabolic functions similar to liver) and regulates key nutrient-responsive proteins. CYD-1 inhibition prolonged lifespan in this setting. ConclusionsCyclin D1 regulates nutrient-mediated physiology in the liver and C. elegans, indicating that it has unexpected and highly conserved metabolic functions. Further study is warranted to define its role in hepatic disease and aging. HighlightsO_LICyclin D1 is induced in hepatocytes with feeding and broadly regulates hepatic gene expression. C_LIO_LIAcute phase response (APR) and senescence-associated secretory phenotype (SASP) proteins are markedly regulated by cyclin D1. C_LIO_LIHepatocyte expression of cyclin D1 is substantially upregulated in aging, premature aging, and MASLD without associated proliferation. C_LIO_LICyclin D1 (CYD-1) regulates nutrient-mediated signaling and lifespan in response to overnutrition in C. elegans. C_LI

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.

Spinal fractures are an important contributor to disability worldwide, particularly in aging populations. However, comprehensive long-term comparisons between China and other major economies remain limited. Using data from the Global Burden of Disease (GBD) 2021 study, we analyzed temporal trends in the incidence, prevalence, and years lived with disability (YLDs) of spinal fractures in China and the overall G20 from 1990 to 2021. Age-standardized rates were assessed using Joinpoint regression and age-period-cohort analysis. Future burden through 2050 was projected using autoregressive integrated moving average modeling, and decomposition analysis was performed to quantify the contributions of demographic and epidemiological factors. Between 1990 and 2021, China experienced substantial increases in absolute burden. Incident cases increased by 52.27%, prevalent cases by 113.66%, and YLDs by 107.21%. The age-standardized prevalence rate (ASPR) and age-standardized YLD rate (ASYR) increased significantly, whereas the age-standardized incidence rate (ASIR) showed a non-significant upward trend. In contrast, the overall G20 aggregate showed increasing absolute case numbers but significantly declining age-standardized rates. Age-period-cohort and age-specific analyses indicated that older adults represented the main burden-bearing population. Projections suggested that Chinas ASIR may decline by 2050, whereas prevalence and YLD burden, particularly among males, may remain relatively high compared with the overall G20 level. Decomposition analysis identified population aging as the major driver of burden growth. China experienced a rising burden of spinal fractures over the past three decades, in contrast to declining age-standardized trends in the overall G20 aggregate. These findings highlight the substantial role of population aging in shaping spinal fracture burden and provide epidemiological evidence for prevention planning and aging-related health policy.

{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.

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.

Frailty is a prevalent geriatric syndrome, and the shortage of objective biomarkers restricts its early diagnosis and intervention. This study aimed to identify robust molecular signatures and diagnostic markers for frailty using bioinformatics analyses of multiple independent datasets. Two transcriptome datasets (GSE144304, n=80; GSE287726, n=70) were obtained from the GEO database. We performed differential gene expression analysis, GO, KEGG and GSEA enrichment, and machine learning (70% training / 30% validation) to screen and validate core biomarkers. Numerous shared differentially expressed genes were identified. Vitamin D metabolism, ABC transporter, and inflammatory/immune pathways were consistently enriched and confirmed by GSEA. Machine learning models based on these signatures showed favorable diagnostic performance. Our study demonstrates that vitamin D metabolic disorders and chronic inflammation are core molecular features of frailty. The identified biomarkers provide new strategies for basic research, early clinical diagnosis, and therapeutic target development for frailty.

Aging can alter macrophage functions through changes in intracellular processing, mitochondrial activity, and chronic inflammatory activation; however, whether aging-associated macrophage deregulation contributes to tumor-associated multinucleated syncytial formation remains poorly understood. Here, we investigated the role of aging macrophages in promoting tumor-like multinucleated syncytia and explored the underlying metabolic mechanisms. Immunohistochemical analyses of metastatic tissue sections from patients with prostate, breast, and lung cancers demonstrated enrichment of CD68+/panCK+ multinucleated tumor-like osteoclast syncytia in elderly patients. Using ex vivo co-culture systems, aged bone marrow-derived macrophages exhibited significantly increased propensity to generate multinucleated syncytia containing proliferative Ki67-positive cancer-associated nuclei. These syncytia displayed attenuated mitochondrial oxidative phosphorylation (OXPHOS) programs characterized by reduced oxygen consumption rates and decreased expression of mitochondrial respiratory proteins, such as ATP5a and SDHB. Pharmacologic inhibition of STAT6 further enhanced syncytial formation and suppressed OXPHOS-associated programs, whereas treatment with the EP2 antagonist C52 partially restored mitochondrial gene expression and reduced syncytial formation. Together, these findings identify a previously unrecognized aging-associated mechanism linking macrophage deregulation, attenuated STAT6-associated mitochondrial programs, and tumor-like multinucleated syncytial formation.

BackgroundAgeing 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 GLP-1 receptor agonists, sodium-glucose cotransporter-2 inhibitors, metformin, and rapamycin are usually evaluated against disease-specific endpoints. ObjectiveTo 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. MethodsWe 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 GLP-1 agonists, sodium-glucose cotransporter-2 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. ResultsThe 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. ConclusionThe 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.

Our research is only as good as our tools allow it to be. The fruit fly Drosophila has been a fundamental discovery platform in uncovering evolutionarily conserved biological underpinnings of ageing, due in large part to an ever-expanding functional genetic toolbox which permits fine-tuneable and cell-type-specific modulation of gene expression with relative ease. However, many existing gene expression systems present limitations for studying fly ageing, including off-target effects for inducing agents that allow temporal control. More recently-generated tools such as the auxin-based gene expression system (AGES) therefore present opportunities as potential alternatives in our methodological repertoire for ageing research. Here we have evaluated the AGES system in a variety of contexts in Drosophila ageing. We find that AGES can effectively induce transgene expression across a range of ages, albeit with tissue-specific efficiency. However, we also observe several phenotypes from auxin feeding, even in non-AGES genotypes, that may confound studies focused on ageing research, including reduced body mass and reduced survival under starvation and oxidative stress conditions. We also observe phenotypes from activating the AGES machinery, including shortened lifespan, that could present challenges for using AGES in longevity-based studies. Nevertheless, we find that AGES can be used to recapitulate at least some effects of well-established pro-longevity interventions - for instance reduced fecundity from expression of a dominant-negative form of the insulin receptor - reinforcing the value of AGES in certain domains. Taken together, our results underscore the need for caution and comprehensive controls in ageing studies that rely on functional genetics, regardless of the chosen genetic toolset.

Background: It is well-established that males have a higher mortality risk than females. Immune cells and their function are known to undergo characteristic changes during aging, and immune cells are known to have sex differences. Immune cells and their function have been linked to mortality risk, but no studies have investigated to what degree, if at all, Immune Cell Biomarkers (ICBs) contribute to the known differences in mortality risk by sex. Methods: Using participant data from the Health and Retirement Study (n = 8,822), we applied multivariable linear regressions adjusting for age, cytomegalovirus (CMV) serostatus, sex, and race/ethnicity to identify differences by sex in 48 immune cell biomarker (ICB, e.g. T cells, B cells, Monocytes, etc.) percentages and counts (measured in 2016). We studied how the associations between ICBs and mortality risk differ by sex using stratified Cox Proportional Hazard (CPH) models. We estimated how inclusion of sex explained the relationship between ICBs and all-cause mortality, and conversely, how inclusion of individual and all ICBs combined explain the relationship between sex and all-cause mortality using multivariable modeling approaches. Results: Differences in ICBs by sex range between 2-38% (39/48 statistically significant). 9 ICBs were significantly associated with mortality risk in the entire sample. While different ICBs were significantly associated with mortality risk in the stratified analyses, particularly with respect to monocyte, B cell, and NK cell populations, adjusting for sex modestly influenced the hazard ratios of the ICBs (sex: 8 ICBs, percent change <5.4%). Furthermore, individual and cumulative contributions of ICBs in explaining the differences in mortality risk by sex were not significant.

Recurrent hypoglycemia increases cognitive impairment in diabetes mellitus patients. Following cerebral neuron injury, endothelial cells provide morphological, metabolic and immune support to damaged neurons. We investigated the inflammatory mechanism involved in hippocampal neuron degeneration. Behavioral experiments, including the open field test (OFT) and the Morris water maze test, were performed to measure cognitive changes. Using a vascular ring experiment, we evaluated vasodilation of the carotid artery. ZBP1 expression was knocked down after transfection with small interfering RNA in a brain endothelial cell line (bEnd3). In this study, PANoptosis, a recently defined form of programmed cell death (PCD), was found to be increased by hypoglycemia in the hippocampus of type 2 diabetic mice in vivo and by low glucose in bEnd3 cells in vitro. ZBP1 knockdown decreased PANoptosis induced by low-glucose stimulation in high-glucose-cultivated bEnd3 cells. RNA transcriptomics sequencing revealed that AGE-RAGE signaling significantly changed after ZBP1 was knocked down in bEnd3 cells. Corresponding biochemical data confirmed that ZBP1 knockdown regulated the advanced glycation end products (AGEs)-Receptor for Advanced Glycation End Products (RAGE) axis in bEnd3 cells. We present the first evidence that hypoglycemia impaired cognition in mice with type 2 diabetes by activating brain endothelial ZBP1-mediated PANoptosis via the AGE-RAGE axis. ARTICLE HIGHLIGHTSO_LIPANoptosis, a newly defined form of programmed cell death, is induced in the hippocampus after recurrent hypoglycemia in male db/db mice. C_LIO_LIZBP1, a sensor of the PANoptosome, was activated in low glucose cultured brain endothelial cells. C_LIO_LIHypoglycemia impairs vasodilation and cognitive function in type 2 diabetic mice. C_LIO_LIOur study indicates that inhibiting ZBP1-PANoptosis and the AGE-RAGE axis may be a potential approach to prevent hypoglycemia-induced cognitive degeneration in individuals with type 2 diabetes. C_LI

Cellular senescence is a tumor-suppressive program characterized by irreversible growth arrest; however, senescent cells can also promote inflammation and alter the tumor microenvironment through the senescence-associated secretory phenotype (SASP). Although SASP induction is regulated by pathways such as p38/NF-{kappa}B/I{kappa}B{zeta}, the mechanisms that restrain excessive or persistent SASP remain largely unknown. Here, we investigated the role of the Ets family transcription factor EHF in SASP regulation during cellular senescence. In IMR-90 human fibroblasts undergoing oncogene-induced senescence, EHF expression was upregulated after the onset of canonical senescence phenotypes. EHF knockdown did not substantially affect senescence establishment but increased SASP-related gene expression. Conversely, overexpression of full-length EHF suppressed SASP-related gene induction during senescence, whereas an ETS-domain-deficient EHF mutant failed to do so, suggesting that this EHF-mediated SASP suppression requires its DNA-binding domain. Furthermore, knockdown of NFKBIZ, which encodes I{kappa}B{zeta} and is induced downstream of NF-{kappa}B signaling, reduced EHF expression during senescence; however, NFKBIZ overexpression increased EHF and SASP-related gene expression. These results link EHF induction to the p38/NF-{kappa}B/I{kappa}B{zeta} inflammatory axis and support a model in which the inflammatory pathway that induces SASP also engages EHF as a negative regulator of SASP. Finally, conditioned medium from senescent cells promoted HCT116 cancer cell migration, and this activity showed a further increase after EHF knockdown. These findings suggest that EHF suppresses senescence-associated inflammatory responses and may function as a senomorphic effector that attenuates SASP-related inflammation without substantially affecting senescence establishment.

BackgroundThe increase in human lifespan without a proportional increase in healthspan imposes a substantial burden on individuals and society. Exceptionally long-lived individuals and members of long-lived families exhibit compression of multi-morbidity. Genetics, and in particular rare protein-altering variants, appear to play an important role in their longevity. MethodsIn this study, we employed a targeted pathway approach to provide functional evidence of the significance of rare variants in the insulin/insulin-like growth factor 1 signalling - mechanistic target of rapamycin (IIS/mTOR) signalling pathway identified in long-lived individuals. To this end, we used CRISPR/Cas9 to introduce these rare genetic variants into mouse embryonic stem cells (mESCs). We subsequently assessed several functional readouts that have previously been associated with lifespan regulation in model organisms and/or IIS/mTOR and mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) signalling pathway activity. ResultsFunctional characterisation revealed that the variants exhibit both shared and distinct effects on the signalling pathways. Principal component analysis of omics-based datasets showed that the variants clustered into two groups, a distribution that corresponds with the grouping observed for a subset of functional readouts. All variant mESC lines exhibited a downregulation in IIS/mTOR and MAPK/ERK signalling pathway activity as well as an increase in Foxo3 expression and FOXO3 binding activity. We identified alterations in lipid and mitochondrial metabolism, including a reduction in mitochondrial DNA levels, which were mostly shared among all variants. All variant mESC lines exhibited a signature implying increased pluripotency. The effects on stress resistance and growth rate diverged between the two variant groups, with partially opposing effects. Group 1 demonstrated a reduced growth rate and increased resistance to a subset of stressors, while Group 2 demonstrated an increased growth rate and reduced resistance to a subset of stressors. ConclusionsHere, we provide evidence that rare genetic variants in the IIS/mTOR and MAPK/ERK signalling pathways identified in long-lived human individuals result in shared functional effects associated with longevity in model organisms. These insights can serve as a foundation to better understand the role of rare variants in the insulin signalling network in the regulation of human longevity. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=68 SRC="FIGDIR/small/728260v1_ufig1.gif" ALT="Figure 1"> View larger version (18K): org.highwire.dtl.DTLVardef@1bf5ebdorg.highwire.dtl.DTLVardef@e4e5dcorg.highwire.dtl.DTLVardef@1aee276org.highwire.dtl.DTLVardef@95f170_HPS_FORMAT_FIGEXP M_FIG C_FIG

Background: Epigenetic clocks based on DNA methylation (DNAm) have emerged as promising biomarkers of biological aging, yet their associations with cognitive performance remain inconsistent. This study investigates the relationship between epigenetic age acceleration and cognitive performance in older adults using 14 DNAm clocks from five generations of development. Methods: We analyzed data from the Berlin Aging Study II (BASE-II) using genome-wide DNAm profiles and cognitive assessments ascertained at baseline (T0) and two follow-up time points (T1, T2) in up to 1,014 individuals. DNAm-based age and age acceleration estimates were calculated using Biolearn and MethylCIPHER. Analyses focused on cross-sectional and longitudinal associations between DNAm clock estimates and cognitive performance, including sex-specific effects and comparisons with frailty as non-cognitive positive control. Results: Among all tested DNAm clocks, DunedinPACE (a third-generation clock) showed the strongest and most consistent associations with cognitive performance. In addition, the fifth-generation SystemsAge framework also demonstrated robust associations with cross-sectional and longitudinal cognitive outcomes. In contrast, second-generation clocks (GrimAge [v2], PhenoAge) showed occasional nominal associations, while first-generation clocks (Horvath [v1], Hannum) and the causally-informed, fourth-generation clocks (e.g. YingCausAge, YingDamAge) showed no noteworthy signals. Likewise, telomere length estimated from DNAm was not strongly associated with cognitive performance in this dataset. Conclusions: Our findings highlight DunedinPACE as a particularly informative biomarker for various aspects of cognitive aging, while other DNAm aging measures showed no consistent associations. Future work should further refine domain-specific epigenetic biomarkers to improve biological aging assessments and achieve a more reliable early detection of cognitive decline.