Aging Cell最新文献

mTOR inhibitors such as rapamycin are among the most robust life-extending interventions known, yet the mechanisms underlying their geroprotective effects in humans remain incompletely understood. At non-immunosuppressive doses, these drugs are senomorphic, that is, they mitigate cellular senescence, but whether they protect genome stability itself has been unclear. Given that DNA damage is a major driver of immune ageing, and immune decline accelerates whole-organism ageing, we tested whether mTOR inhibition enhances genome stability. In human T cells exposed to acute genotoxic stress, we found that rapamycin and other mTOR inhibitors suppressed senescence not by slowing protein synthesis, halting cell division, or stimulating autophagy, but by directly reducing DNA lesional burden and improving cell survival. Ex vivo analysis of aged immune cells from healthy donors revealed a stark enrichment of markers for DNA damage, senescence, and mTORC hyperactivation, suggesting that human immune ageing may be amenable to intervention by low-dose mTOR inhibition. To test this in vivo, we conducted a placebo-controlled experimental medicine study in older adults administered with low-dose rapamycin. p21, a marker of DNA damage-induced senescence, was significantly reduced in immune cells from the rapamycin compared to placebo group. These findings reveal a previously unrecognised role for mTOR inhibition: direct genoprotection. This mechanism may help explain rapamycin's exceptional geroprotective profile and opens new avenues for its use in contexts where genome instability drives pathology, ranging from healthy ageing, clinical radiation exposure and even the hazards of cosmic radiation in space travel.

Aging is a multifactorial process influenced by genetic, environmental, and metabolic factors. Dysregulated nutrient sensing and metabolic dysfunction are hallmarks of aging, and reduction of insulin/IGF-1 signaling or metabolic interventions such as caloric restriction extend lifespan across species. Endogenous metabolites reflect and mediate these metabolic cues, linking nutrient status to epigenetic and transcriptional programs by serving as cofactors for chromatin-modifying enzymes or as allosteric modulators of transcription factors. Some metabolites have emerged as key regulators of longevity, integrating into networks to concurrently influence multiple aging-related pathways. In this review, we summarize evidence supporting the lifespan-extending effects of key endogenous metabolites across diverse model organisms and discuss their mechanisms of action. These insights underscore the potential of targeting metabolic networks as a multifaceted strategy to delay aging. Finally, we consider the translational promise of metabolite-based interventions to extend healthspan while minimizing adverse effects, and we note remaining challenges such as optimal dosing, context-specific effects, and demonstrating efficacy in humans.

Neovascular age-related macular degeneration (nAMD) is a major cause of irreversible vision impairment in elderly populations, characterized by pathological angiogenesis beneath the macula. Although anti-VEGF therapies have demonstrated clinical effectiveness, significant challenges including drug resistance and the need for frequent intravitreal injections persist. As natural nanovesicles, exosomes derived from mesenchymal stem cell (MSC) can mediate intercellular communication, making them an attractive alternative for modulating cellular processes. This study explored the anti-angiogenic effects of MSC-derived exosomes in nAMD, with particular emphasis on the role of a specific exosomal lncRNA lnc-AGT-3. Our results showed that lnc-AGT-3 expression was reduced in both nAMD patients and choroidal neovascularization (CNV) models, and its overexpression effectively inhibited pathological angiogenesis in vitro and in vivo. Mechanistically, lnc-AGT-3 enhanced the p53 signaling pathway by blocking the ubiquitination and degradation of p53 and ultimately inhibited neovascularization, a process potentially linked to its direct interaction with heterogeneous nuclear ribonucleoprotein K (hnRNP K). Our findings position MSC-derived exosomes enriched with lnc-AGT-3 as an innovative therapeutic paradigm for nAMD, acting through p53 pathway modulation to potentially overcome current treatment limitations.

With the increasing trend of delayed childbearing, the decline in oocyte quality associated with advanced maternal age has emerged as a pressing concern. However, the mechanism remains unclear, and effective strategies for improvement are currently lacking. Previously, we reported that the downregulation of the mevalonate pathway in aged granulosa cells (GCs) contributed to meiotic defects in oocytes, which may implicate farnesyl pyrophosphate-mediated protein farnesylation. Nevertheless, the role of farnesylation in ovarian aging and its impact on oocytes requires further investigation. In this study, using cumulus-oocyte complexes (COCs) from young and aged female mice, we observed impaired cumulus expansion and concurrent meiotic defects during aged oocyte maturation, accompanied by significantly reduced protein farnesylation in aged GCs. Furthermore, inhibiting farnesylation with FTI-277 in young COCs recapitulated the aging phenotype, disrupting cumulus expansion and inducing meiotic defects similar to those in aged COCs. Conversely, restoring farnesylation via farnesol supplementation effectively ameliorated these deficits in both aged COCs (in vitro) and aged mice (in vivo). Proteomic analysis and experimental validation identified prostaglandin E2 synthase 2 (PTGES2) as a farnesylated protein. Mechanistically, age-related decline in PTGES2 farnesylation in GCs reduces its endoplasmic reticulum localization and impairs prostaglandin E2 (PGE2) production, thereby compromising PGE2-dependent cumulus expansion and oocyte maturation. Collectively, our findings highlight the detrimental effects of decreased farnesylation in aged GCs on oocyte quality and propose a potential therapeutic strategy for improving the developmental competence of aged oocytes.

Senescent cells display indefinite growth arrest and a pro-inflammatory, senescence-associated secretory phenotype (SASP). As the accumulation of senescent cells in tissues with age plays detrimental roles in age-related pathologies, there is much interest in finding therapeutic strategies to eliminate them or suppress the SASP. In this study, we investigated the impact of the secretome and extracellular vesicles (EVs) derived from human trophoblast stem cells (hTSCs) on senescent human fibroblasts. We found that the hTSC conditioned medium (hTSC-CM), and in particular the EVs (hTSC-EVs), significantly reduced the levels of mRNAs encoding SASP factors and the secretion of SASP factors including CXCL1, IL8, and GDF15. Proteomic analysis of hTSC-CM and EVs indicated an enrichment in proteins involved in cell adhesion, tissue repair, and remodeling of the extracellular matrix (ECM). Furthermore, incubation of senescent cells with hTSC-EVs attenuated DNA damage and inflammatory signaling, at least in part by suppressing the function of NF-κB, a major transcriptional regulator of the SASP program. Our findings underscore the value of hTSC-CM and EVs therein in therapeutic approaches directed at senescent cells.

Synaptic vesicle glycoprotein 2A (SV2A), a transmembrane protein widely localized to synaptic vesicles, serves as a key indicator of synaptic loss in Alzheimer's disease (AD). In this study, adeno-associated virus (AAV) was injected by brain stereotactic injection technique to construct SV2A-overexpressing APP/PS1 mice, then the effects of SV2A on amyloid precursor protein (APP) degradation and its molecular mechanism were further explored in vivo or in vitro. Our results demonstrated that SV2A overexpression significantly reduced Aβ plaque deposition in brain tissue of APP/PS1 mice. Mechanistically, SV2A was identified as a novel APP-binding protein that attenuated the amyloidogenic processing of APP by inhibiting its interaction with β-site APP cleaving enzyme 1 (BACE1). Furthermore, SV2A overexpression altered the subcellular distribution of APP, shifting its localization away from the endosomal-lysosomal compartments. Collectively, our findings unveil SV2A as a critical regulator of APP metabolism and propose it as a promising therapeutic target for intervening in the early pathological progression of AD.

With an aging population, the incidence of age-related hearing loss (ARHL) continues to increase. Aging cells exhibit reduced nicotinamide adenine dinucleotide (NAD⁺) levels and impaired autophagy; however, the mechanisms underlying these processes remain largely unclear. In our study, we assessed the role of nicotinamide nucleotide adenylate transferase 1 (NMNAT1) in cochlear hair cell aging using D-galactose (D-gal)-induced aging HEI-OC1 cells and cochlear explants. We observed a significant reduction in NMNAT1 expression in HEI-OC1 cells and cochlear hair cells treated with D-gal. Notably, NMNAT1 overexpression activated autophagy and decelerated hair cell aging. Metabolomic analysis revealed a dysregulated tricarboxylic acid cycle in Nmnat1-knockout cells, indicating that NMNAT1 regulates autophagy and metabolic pathways that affect hair cell aging. These findings offer novel insights into the association between autophagy and metabolism during aging and highlight NMNAT1 as a potential therapeutic target for the prevention and treatment of ARHL.

Aging drives a progressive decline in vascular health, undermining endothelial function, neurovascular coupling (NVC), and blood–brain barrier (BBB) integrity, three processes essential for maintaining cerebral perfusion and cognitive resilience. Central to these age-related deficits is mitochondrial dysfunction, which disrupts redox balance, bioenergetics, and nutrient-sensing pathways within vascular cells, thereby promoting oxidative stress, impaired mitophagy, mitochondrial fragmentation, and endothelial senescence. These molecular derangements are especially consequential in the brain's microvasculature, where the exquisite metabolic demands of neural tissue depend on intact endothelial signaling. As a result, cerebrovascular aging becomes a major driver of cognitive decline and vascular contributions to dementia. This review synthesizes current mechanistic insights into mitochondrial and endothelial pathways that shape vascular aging, with particular focus on the neurovascular unit. We further highlight emerging evidence that time-restricted feeding/eating (TRF/TRE), a circadian-aligned dietary intervention that limits food intake to a daily feeding window without reducing calories, can restore mitochondrial function, activate adaptive nutrient-sensing networks including AMPK and SIRT1, suppress mTOR signaling, and promote metabolic switching toward ketone synthesis and utilization. Through these mechanisms, TRF enhances endothelial resilience, preserves NVC and BBB integrity, and may counteract the cerebrovascular processes that accelerate cognitive aging. Understanding how TRF/TRE re-engages mitochondrial and vascular repair programs offers a translational framework for developing accessible, non-pharmacological strategies to extend healthspan and mitigate age-related cognitive impairment.

Spaceflight exposes astronauts to a combination of environmental stressors such as microgravity, ionizing radiation, circadian disruption, and social isolation that induce phenotypes of aging. However, whether these exposures accelerate biological aging remains unclear. In this exploratory study, we assessed 32 DNA methylation-based biological age metrics in 4 astronauts during the Axiom-2 mission at pre-flight, in-flight (day 4 and 7), and post-flight (return days 1 and 7). On average, Epigenetic Age Acceleration increased 1.91 years by flight day 7. Upon return to Earth, biological age decreased in all crew members, with older astronauts returning to pre-flight estimates and younger astronauts showing a biological age significantly lower than pre-flight levels. We found that shifts in immune cell composition, specifically regulatory and naïve CD4 T-cells, accounted for a significant portion of the observed age acceleration in several clock models. However, even after adjusting for cell composition, chronological age and mortality-based predictors showed acceleration during spaceflight. These findings suggest that spaceflight induces rapid, yet reversible, epigenetic changes associated with aging, positioning spaceflight as a platform to study human aging mechanisms and test geroprotective interventions.

This systematic review and meta-analysis aims to identify the most frequently reported blood-based biomarkers (BBMs) in randomised controlled trials (RCTs) addressing sarcopenia management, and to perform a preliminary evaluation of the effects of sarcopenia-specific interventions on BBMs concentrations. Medline, Embase and CENTRAL databases were searched to retrieve RCTs published until March 2024 (PROSPERO: CRD42024603238) on older participants with sarcopenia. Eligible studies applied a consensus definition of sarcopenia and reported BBM values before and after intervention. Meta-analyses were performed for BBMs reported in a minimum of 2 RCTs using a random effects model with a standardised mean difference (SMD) and a 95% confidence interval. Among 58 RCTs on sarcopenia management, only 21 (36.2%) assessed BBMs and none involved pharmacological interventions. Altogether, 47 distinct BBMs were identified. The most frequently reported were C-reactive protein, interleukin 6, tumour necrosis factor α, Insulin-like Growth Factor 1 (IGF-1). Muscle-specific BBM, follistatin, growth differentiation factor 8 and 15 were assessed in only 2 RCTs. Among non-muscle-specific BBMs, IGF-1 was significantly impacted by the studied interventions (SMD = 0.46, CI = [0.04; 0.88]). However, this change was not significant when analyses were restricted to RCTs reporting significant improvement in key sarcopenia measures. Despite substantial heterogeneity, few BBMs assessed in sarcopenia RCTs were muscle-specific and limited biomarkers responded to interventions. There is an urgent need to adopt recommendations regarding muscle-specific BBMs to be assessed in sarcopenia RCTs. Developing a standardised Core Outcome Set for sarcopenia intervention studies would enhance the standardisation of sarcopenia RCTs and ultimately improve disease management.