Inflammaging, driven by monocyte dysregulation, is a hallmark of immunosenescence. Toll-like Receptor 4 (TLR4) pathway hyper-activation accelerates cellular senescence and systemic inflammatory damage, while microRNA-146a (miR-146a) constrains pro-inflammatory cytokine release by targeting IRAK-1. Plant-derived triterpenoids are promising geroprotective agents, but standardized, scalable biotechnological production remains challenging. We established a sustainable in vitro callus culture from Red Sentinel to obtain a standardized triterpenoid-rich extract (RSE). GC-MS/FID analysis quantified its pentacyclic triterpene content (ursolic and oleanolic acids) within a soluble phytocomplex matrix, while X-ray Photoelectron Spectroscopy (XPS), Ultraviolet Photoelectron Spectroscopy (UPS), and thermal analysis (TGA/DSC) characterized surface elemental states, work function, and thermal stability. Biological efficacy was tested in human U937 monocytes, and molecular docking was performed against the TLR4/MD-2 complex. RSE showed high thermal stability and distinct surface chemistry, with specific oxygenated carbon functional states. In U937 monocytes, RSE non-cytotoxically attenuated pro-inflammatory signaling, significantly upregulating miR-146a, down-regulating IRAK-1, and reducing IL-6 secretion. Docking confirmed strong interactions between the pentacyclic triterpenes and the TLR4/MD-2 hydrophobic pocket. These results indicate that plant cell culture technology can generate standardized phytocomplexes capable of modulating the miR-146a/IRAK-1/IL-6 axis, counteracting monocytic inflammaging, and support the value of combining surface physics and molecular biology in anti-aging nutraceutical research.
BACKGROUND:Asian Indians exhibit disproportionately high rates of prediabetes progression to type 2 diabetes, associated with accelerated biological aging. Metformin has been proposed to exert anti-aging effects independent of glycemic control; however, adequately powered randomized controlled trials evaluating telomere biology in prediabetes are lacking. METHODS:We conducted a participant-blind, outcome-assessor-blinded randomized placebo-controlled trial in North Indian individuals aged 30-60 years with prediabetes. A total of 322 individuals were screened, of whom 195 were excluded for various reasons. Consequently, 127 participants met the eligibility criteria and were enrolled in the study. Participants received metformin 500 mg twice daily (n = 63) or placebo (n = 64) for 24 weeks, alongside lifestyle counseling. Primary outcomes were leukocyte telomere length (LTL), telomerase activity (TA), and longevity gene expression (SIRT1, p66Shc, p53, mTOR) measured in peripheral blood mononuclear cells using quantitative real time PCR. Secondary outcomes included anthropometric and metabolic parameters. RESULTS:Among 127 randomized participants, 112 (88.2%) completed the study. Metformin significantly increased LTL compared to placebo (mean change +0.247 ± 0.298 vs +0.036 ± 0.068; 29.6% vs 4.4% elongation; between-group p < 0.0001), TA increased substantially in the intervention group (+0.528 ± 0.412, 39.3% increase, p < 0.0001), vs minimal change in placebo (-0.019 ± 0.279, p = 0.6035; between-group p < 0.0001). SIRT1 expression increased significantly (Δ+0.249 ± 0.535 vs +0.029 ± 0.097; p = 0.0037), while mTOR expression showed a context-dependent increase requiring mechanistic interpretation (p = 0.0004). These effects occurred independent of sustained glycemic improvement. CONCLUSIONS:Metformin over 24 weeks significantly elongated LTL, raised TA and upregulated SIRT1, independent of glycemic control. While demonstrating metformin's geroprotective potential in healthy Asian Indians, the marked LTL response requires cautious interpretation, and validation in larger, long-term studies is needed.
Aging can be viewed as a progressive departure from physiological homeostasis accompanied by increasing morbidity and mortality risk. This perspective motivates two complementary but non-equivalent approaches. The first is homeostatic dysregulation (HD), which summarizes multivariate deviation from a prespecified reference distribution. The second comprises supervised aging measures, which are target-dependent model outputs trained to predict outcomes such as chronological age, mortality, morbidity, functional status, or pace of aging. Their outputs are often only modestly correlated and do not represent the same latent biological age or a geometric distance. We propose that their joint value should be tested for outcome-specific risk stratification, longitudinal monitoring, and gerotherapeutic trials. Such applications require prospective validation, calibration, and evidence that each measure adds information beyond chronological age and established clinical predictors.
Aging is a multifactorial process that is best described in terms of the progressive acquisition of multiple layers of phenotypic changes, such as epigenetic modifications, inflammation, and metabolic dysregulation. DNA methylation clocks have been extensively used to construct epigenetic clocks based on the DNAm profiles that can be used to estimate biological age and predict age-associated outcomes. Nevertheless, the vast majority of clocks constructed so far have been based on linear models, which are unlikely to fully account for the heterogeneity and non-linearity of survival-related DNAm signatures. In this work, we constructed a heterogeneous stacked ensemble survival model based on DNAm data obtained from the Framingham Heart Study. We first identified 190 CpG loci using elastic net Cox regression and subsequently constructed a survival prediction model based on the fusion of five complementary survival models by means of a neural network meta-learner. The prediction power of the survival model was evaluated in an external validation cohort, where we observed strong performance for predicting all-cause mortality that significantly exceeded PhenoAge and was statistically comparable to GrimAge. These performance estimates were derived in cohorts of European ancestry and externally validated in postmenopausal women aged 50-79 years, and should therefore be interpreted as applicable only to demographically similar populations.
As the aging population increases, exploring effective strategies to delay aging and promote healthy longevity has become a crucial topic in the life sciences. Puerarin (PUE) is a natural isoflavone derivative derived from Pueraria lobata, a plant widely recognized for its dual role as both a food and a medicinal herb. While PUE is known for its diverse pharmacological properties, its role in aging regulation and the associated molecular mechanisms are not yet fully elucidated. In this study, we found that PUE markedly extends the healthy lifespan of Caenorhabditis elegans and mitigates aging-related phenotypes, including lipofuscin accumulation and decreased locomotor capacity. Through genetic screening and functional validation, we demonstrated that PUE facilitates the nuclear translocation of the transcription factor HLH-30 (the mammalian homolog of TFEB) in an AMPK-dependent manner, thereby regulating autophagy. Importantly, this autophagic response was essential for the lifespan-extending effects of PUE. Additionally, PUE enhanced the oxidative stress resistance of C. elegans via the AMPK-TFEB signaling pathway, an effect characterized by reduced reactive oxygen species (ROS) accumulation and increased activities of antioxidant enzymes such as superoxide dismutase (SOD) and glutathione (GSH). The findings establish a mechanistic rationale for applying PUE in aging delay and age-related disease prevention and underscore the potential significance of medicinal food plants in developing anti-aging strategies.
Late-onset epilepsy (LOE) remains of unknown aetiology (LOEU) in around 20% of cases. Longitudinal studies have demonstrated the presence of early cognitive impairment at seizure onset, progressive memory decline and a substantially elevated risk of dementia within a decade of diagnosis, with an increased risk of subsequent neurodegenerative disorders, particularly Alzheimer's disease (AD). LOEU is associated with cognitive network alterations and epileptiform activity, although links remain unclear. Further emerging data suggest that neurodegenerative processes related to β-amyloid and tau pathology may precede the onset of epilepsy. Although epilepsy is highly prevalent among older adults, its impact on quality of life remains unclear, with affective symptoms and sleep disturbances as key determinants of subjective well-being. These findings suggest that LOEU should be reconceptualised as a multidimensional neurological condition.This protocol advocates an integrated approach, combining neuropsychological assessment, advanced biomarkers, neurophysiological measures and systematic sleep evaluation to identify high-risk phenotypes and define optimal windows for neuroprotective interventions in LOEU. This strategy could improve the early detection of cognitive decline, guide personalised management, and ultimately enhance quality of life, while contributing to the long-term sustainability of healthcare systems in an ageing population, focusing on LOEU as a model for dementia prevention.
Aging is a dynamic and time-dependent process characterized by progressive functional decline across biological systems. Key hallmarks, including genomic instability, telomere attrition, loss of proteostasis, mitochondrial dysfunction, and immunosenescence, have been widely described, each reflecting distinct yet interconnected mechanistic frameworks. Rather than acting in isolation, these processes arise from complex interactions among cellular stressors, impaired repair mechanisms, and the cumulative burden of maladaptive responses. This system-level perspective explains the inter-individual variability in aging trajectories. Centenarians represent an extreme and informative model of successful aging, in which the balance between damage accumulation and repair is shifted toward the maintenance of physiological function. Their exceptional longevity is supported by coordinated genetic, epigenetic, metabolic, and immunological adaptations that enhance resilience to age-related stressors. Here, we summarize the biological drivers and theoretical frameworks of aging within an integrative context, focusing on mechanisms associated with extended healthspan in centenarians. We also examine the contribution of major animal models, highlighting their complementary roles in elucidating conserved and species-specific aging pathways. Overall, aging outcomes reflect a dynamic equilibrium between damage and repair processes. Understanding how this balance is modulated in long-lived individuals may inform strategies to promote healthy aging and delay the onset of age-related diseases.
Brain aging and age-associated neurological diseases, such as Alzheimer’s Disease (AD), Parkinson’s Disease (PD), and Amyotrophic Lateral Sclerosis (ALS), are largely attributed to epigenetic drift which is characterized by the gradual accumulation of alterations in neural cell methylation patterns over time. These methylation changes are particularly evident in transposable element (TE)-derived sequences such as Long interspersed element-1 (LINE-1) which comprises approximately 17% of the human genome. During aging, LINE-1 elements gradually lose their methylation, as well as the regulatory safeguard mechanisms that usually keep them inactive. This repression loss can lead to LINE-1 reactivation, contributing to harmful effects including genomic instability, neuroinflammation, and more. Together these findings indicate that impaired epigenetic maintenance, especially in repetitive genome regions, plays a key role in biological aging of neurons and glial cells. In this narrative review, we discuss the methylation dynamics and regulatory mechanisms of LINE-1 retrotransposons, their activation processes during aging, and contribution to age-associated neurological diseases. We also highlight the potential of targeting LINE-1 methylation to restore methylation homeostasis, epigenetic stability and delay brain aging.
Unlike younger populations, older individuals often live with multiple systemic conditions that may influence neurofilament light chain (NfL) levels beyond true neuroaxonal injury, complicating its interpretation as a pure marker of neuronal damage. While prior work has examined determinants of blood NfL, none has specifically addressed its contextualization in the geriatric multimorbid setting. This narrative review critically examines the main non-neurological determinants of circulating NfL in older adults focusing on age, renal function, BMI, glycemic dysregulation, cardiovascular disease, and chronic hypoxia and discussing their clinical implications. Renal dysfunction and BMI appear to act as pharmacokinetic modifiers, altering NfL concentrations through reduced clearance and plasma volume dilution, respectively, without necessarily reflecting increased neuronal injury. In contrast, aging, dysglycemia, cardiovascular disease, and hypoxia may function as biologically active confounders, potentially contributing to neuroaxonal damage through neuronal attrition, microvascular injury, cerebral hypoperfusion, and oxidative stress. This distinction carries clinical implications: pharmacokinetic confounders call for adjusted reference ranges, while biologically active confounders represent true sources of neurological vulnerability warranting independent attention. Blood NfL levels in the geriatric population mirror complex neuro-systemic interactions requiring an integrated interpretive approach. Longitudinal monitoring and elderly-specific multivariate models could improve NfL's reliability as a tool in geriatric neurology.
The identification of reliable biomarkers of ageing represents a major challenge in biomedical research, particularly in the context of increasing life expectancy and the growing burden of chronic diseases. Among potential candidates, the ABO blood group system has attracted interest as a stable genetic trait potentially associated with inter-individual variability in ageing-related outcomes. This narrative review critically examines current evidence linking ABO blood groups to age-related diseases and biological mechanisms of ageing. A structured search of major biomedical databases was performed, focusing primarily on studies published in the last five years and complemented by seminal earlier reports. Current findings indicate associations between ABO phenotypes and several chronic conditions, including cardiovascular disease, thrombotic disorders, diabetes, cancer, allergies, and cognitive disorders, which substantially contribute to morbidity and mortality in older adults. However, data are contradictory and dependent on ethnicity, genetic background and environmental factors. Non-O blood groups consistently exhibit a higher risk of thrombotic and cardiovascular events, likely mediated by differences in coagulation factors, endothelial function, and hemostatic balance. ABO-related phenotypic variation may also influence processes implicated in ageing, including vascular dysfunction, chronic low-grade inflammation, immune remodeling, glycosylation pathways, cellular senescence, and host-microbiome interactions. However, evidence supporting a direct relationship between ABO blood groups and longevity remains inconsistent and appears to be population dependent. Overall, current data suggest that ABO blood groups are unlikely to represent independent biomarkers of ageing, but rather modest, context-dependent modifiers of biological pathways contributing to susceptibility to age-related diseases. Further longitudinal and mechanistic studies are needed to clarify their role in healthy and pathological ageing trajectories. Summary ABO blood group system has been associated with susceptibility to several age-related diseases (ARDs). Non-O blood groups show a higher risk of thrombotic and cardiovascular events. Although some studies also suggest a relationship between ABO phenotype and longevity, findings remain inconsistent and appear to vary across populations. Potential mechanisms linking ABO blood groups to ageing include effects on inflammation, vascular function, immune responses, and host-microbiome interactions. Overall, current evidence indicates that ABO blood group is unlikely to represent an independent biomarker of ageing, but rather a modest and context-dependent factor that can influence aging-related mechanisms and contribute to the ARD development.
Interventions targeting conserved aging pathways can markedly extend lifespan in model organisms, yet their efficacy declines with increasing organismal complexity. While this phenomenon is well documented, the underlying constraints remain poorly defined. Here, we integrate comparative experimental data with mechanistic insights to propose a unifying framework explaining the declining ceiling of lifespan extension. We show that in simple organisms, aging is governed by a limited number of high-leverage pathways, whereas in mammals it emerges from distributed, multi-tissue regulatory systems characterized by redundancy, feedback, and competing physiological constraints. By synthesizing findings from Caenorhabditis elegans, Drosophila melanogaster, and rodent models, we identify key determinants of this transition, including metabolic organization, genetic redundancy, endocrine regulation, microbiome interactions, and pharmacokinetic complexity.
Leukocyte telomere length (LTL) is a biomarker of cellular ageing, with shorter telomeres linked to increased risk of age-related diseases. Although adverse early-life environments have been associated with shorter LTL in later adulthood, it remains unclear whether such differences are already established by early adulthood and which early-life exposures are most influential. Using data from the Avon Longitudinal Study of Parents and Children (ALSPAC), we analysed LTL in 2014 participants at a mean age of 24.5 years, examining associations with 50 parental, childhood, and adolescent factors assessed predominantly before age 17. In a subset of 893 participants with repeated measurements at ages 17 and 24, we also examined telomere length change across late adolescence. Longer LTL was associated with older parental age at delivery, particularly maternal age, while shorter LTL was associated with maternal passive smoking during pregnancy and greater cumulative trauma exposure during adolescence. Telomere length declined by approximately 1.1% per year between ages 17 and 24, with little evidence that exposures influenced attrition rates. These findings suggest that variation in LTL by early adulthood primarily reflects prenatal and earlier developmental influences, consistent with early biological embedding.
Heat shock transcription factor HSF1 maintains proteome integrity via the induction of heat shock proteins. Here, we provide a comprehensive overview on the structure, function and regulation of HSF1 in multiple organisms. We summarize the aging-associated changes of HSF1 function, the reduced inducibility of the heat shock response, leading to a model of age-related stochastic HSF1 activity decline. Besides, we review basal, non-canonic HSF1 functions through regulating distinct transcriptional outputs which support development, reproduction, tissue proteostasis maintenance, growth- and cancer-related anabolic processes. Based on major observations in the nematode C. elegans demonstrating differential regulation of these outputs, we propose a novel mechanistic framework that draws on the life history-coupled programmed remodeling of its transcriptional function at the onset of reproduction. The HSF1 output selection model accounts for the coexistence of diminished stress inducibility with sustained or increased basal HSF1 activity and explains why broad HSF1 activation may benefit proteotoxic diseases but pose risks in cancer-prone conditions. Experimental approaches leveraging age- and tissue-specific transcriptomic, chromatin, and post-translational analyses are outlined, emphasizing selective restoration of protective HSF1 outputs over indiscriminate activation.
Circulating sex hormone levels decrease in aging, influencing cerebrovascular health. Estradiol has been shown to support female vascular and brain health, though its effects across the menopausal transition remain unknown. Similarly, the influence of testosterone and other hormones in females is not clear. In males, testosterone is associated with positive health outcomes, but the effects of estradiol and other hormones are undetermined. Here, 187 females were categorized as premenopausal, perimenopausal or postmenopausal and 154 males as younger [< 50 years] or older [50-70 years]. Magnetic resonance imaging quantified cerebral blood flow (CBF), arterial transit time (ATT), relative cerebrovascular reactivity (CVR) and a blood draw for circulating sex hormones. In females, estradiol was associated with lower ATT during perimenopause. Testosterone exhibited a U-shaped relationship with CVR in premenopausal females, yet was linked to lower CBF and CVR, and longer ATT in postmenopausal females. In males, higher testosterone was correlated with greater CBF in younger participants, while higher estradiol and follicle-stimulating hormone were associated with lower CBF in older males. These findings highlight life stage- and sex-specific associations with between hormones and cerebrovascular markers, emphasizing the potential for hormone-targeted, age and stage-specific interventions to support cerebrovascular health.
Animal lifespan depends on coordinated gene expression networks that regulate metabolic adaptation, proteostasis, and stress resilience in response to environmental challenges. Histone variants are key regulators of chromatin dynamics, orchestrating nucleosome remodeling, DNA accessibility, and gene expression. While the role of histone H3.3 in aging and animal survival has been explored across model systems, the contribution of other replication-independent histone variants remains less well-defined. Here, we demonstrate that the evolutionarily conserved histone variant HTZ-1/H2A.Z is essential for organismal survival. In the nematode Caenorhabditis elegans, loss of HTZ-1/H2A.Z disrupts gene expression programs associated with longevity, including those activated in insulin/IGF-1 deficient daf-2 mutants and in mitochondrial Complex I deficient animals. Together, our findings show that HTZ-1/H2A.Z regulates gene expression programs that coordinate metabolic and proteostatic pathways, thereby fine-tuning stress responses and promoting lifespan in animals.
Cardiac calcification is an age-associated pathological process that contributes to cardiac dysfunction, arrhythmia, and sudden cardiac death, yet its underlying mechanisms remain unclear. Cardiac fibroblasts (CFs) have emerged as key mediators of ectopic calcification through osteogenic differentiation. Proprotein convertase subtilisin/kexin type 9 (PCSK9), a key regulator of cholesterol metabolism, has been implicated in cardiovascular pathology beyond its canonical role, but its involvement in cardiac calcification is unknown. In this study, aged mice exhibited cardiac dysfunction, interstitial fibrosis, and myocardial calcium deposition, accompanied by upregulation of osteogenic markers, including Runx2, OCN, and Osx. PCSK9 expression was increased in aged hearts and enriched in DDR2-positive cells. In vitro, senescent CFs displayed enhanced osteogenic differentiation, characterized by increased calcium deposition, alkaline phosphatase activity, and elevated expression of osteogenic markers. Recombinant PCSK9 promoted osteogenic differentiation in young CFs, whereas genetic deletion of PCSK9 attenuated these effects in senescent CFs. Pharmacological experiments suggest that PCSK9-mediated osteogenic differentiation is associated with activation of the ATF4 pathway and upregulation of Runx2 expression. These findings support a role for the PCSK9-ATF4-Runx2 signaling axis in osteogenic differentiation of CFs, providing new insights into age‑related cardiac calcification and identifying this pathway as a hypothesis‑generating candidate for future investigation.
Exceptional longevity has increasingly been recognized as a distinct biological state associated with unique immune and inflammatory profiles. However, the innate immune characteristics associated with extreme aging, particularly following viral infections, remain incompletely understood. Toll-like receptors (TLRs) play central roles in pathogen sensing and inflammatory signaling, including during SARS-CoV-2 infection, yet their relationship with exceptional longevity has not been clearly defined. Here, we quantified TLR gene expression in peripheral blood from unvaccinated older adults who recovered from COVID-19 prior to vaccination (38 nonagenarians and 8 centenarians). Among the receptors analyzed, TLR2 was the only gene differentially expressed, showing lower expression in COVID-19-recovered centenarians compared with recovered nonagenarians. Importantly, this difference was not associated with COVID-19 severity, suggesting that TLR2 expression in this cohort reflects an age- and recovery-associated immune characteristic rather than clinical outcome. Exploratory comparison with centenarians without prior COVID-19 (n = 10) indicated that reduced TLR2 expression was not simply a constitutive hallmark of extreme aging, but may instead reflect a distinct post-infectious innate immune remodeling. Together, these findings identify a distinct TLR2-associated immune signature in centenarians recovered from COVID-19 and suggest that exceptional longevity may be associated with a distinct post-infectious innate immune remodeling following SARS-CoV-2 infection.
We discovered a Sjögren's disease (SjD)-like state in the programmed cell death 1+ (PD-1⁺) niches of the spleen and submandibular glands of 36-week-old female Nishiura (NI) mice, characterized by the formation of tertiary lymphoid structures (TLS) by senescence-associated (SA) immune cells, production of anti-α-amylase autoantibodies, and reduced saliva secretion. Co-culturing B220⁺/PD-1⁺ cells derived from the spleens of NI mice with CD4+/PD-1+/CD153+ (SA-Tfh) cells for 48 h enhanced IgG and senescence-associated secretion phenotype production in both cell types. Conversely, transplantation of spleen-derived SA-Tfh cells from NI mice expanded TLS in the submandibular glands of recipient mice. Meanwhile, a retrospective histopathological cohort study of seven SjD patients aged 50-70 revealed that the fibrogenic capacity per SA-Tfh cell significantly increased with age. Collectively, these data suggest that TLS formation associated with SA immune cells in the submandibular glands is a key mechanism in SjD.
Aging is a major driver of hematological impairment and a significant risk factor for hematologic malignancies. CD34⁺ hematopoietic stem and progenitor cells (HSPCs) represent a critical cellular compartment in which age-related changes converge to promote leukemogenesis. This review synthesizes contemporary findings on the interplay between intrinsic hallmarks of aging, including genomic instability, telomere attrition, epigenetic drift, and mitochondrial dysfunction, and extrinsic factors, including chronic inflammation and bone marrow niche remodeling, in the reprogramming of CD34⁺ cell fate. These alterations promote clonal hematopoiesis of indeterminate potential (CHIP), impair immune competence, and increase susceptibility to malignant transformation. Special attention is directed towards CD34⁺CD38⁻ subsets, which possess leukemic stem cell (LSC) functionality and demonstrate resistance to standard treatments. Emerging biomarkers, including CD123, CD96, IL1RAP, and CD133, are discussed in relation to disease progression and therapeutic targeting. We emphasize how aging-related inflammatory signaling and metabolic changes preferentially benefit pre-leukemic clones. Ultimately, we investigate therapeutic approaches designed to disrupt leukemogenesis by focusing on aging mechanisms, the senescent microenvironment, and vulnerabilities specific to leukemic stem cells (LSCs). This review contextualizes CD34⁺ cell biology within aging mechanisms, offering a cohesive view on illness onset and highlighting prospects for early intervention in older populations.
