Biomarkers that correlate with age are essential tools for understanding aging and lifespan variation. DNA methylation (DNAm) changes predictably with age in parts of the genome. In humans, epigenetically "old" individuals relative to their chronological age also have a reduced…
Abstract
Biomarkers that correlate with age are essential tools for understanding aging and lifespan variation. DNA methylation (DNAm) changes predictably with age in parts of the genome. In humans, epigenetically "old" individuals relative to their chronological age also have a reduced life expectancy but whether the link between epigenetic age and lifespan is a general feature remains an open question. We explored age-related changes in DNAm in the zebra finch (Taeniopygia castanotis), a key avian model species, using 100 longitudinal wholegenome methylomes from 50 captive adults monitored until their natural death. We found genome-wide hypomethylation with age, with DNAm decreasing faster in individuals with shorter lifespans and identified 29 CpG sites where DNAm changed significantly with age. We developed an epigenetic aging clock based on 119 CpG sites, that predicted chronological age with high accuracy (median absolute deviation = 0.68 years, 8.2% of maximum lifespan in our dataset). Females raised in large broods, which have shorter lifespans, showed increased epigenetic age acceleration, consistent with faster biological aging. However, epigenetic age acceleration did not predict lifespan or remaining lifespan. In contrast, the within-individual rate of change in epigenetic age significantly predicted lifespan: faster epigenetic aging was associated with a shorter lifespan. Moreover, a "doom" clock, trained to predict post-sampling lifespan, successfully predicted remaining lifespan. Our findings provide the first evidence that DNAm provides a window into biological aging in birds, showing how early-life environments shape the aging trajectory via the epigenome and underscore the value of longitudinal data in aging studies.
AI-generated longevity analysis. Check claims against the paper.
Summary
The paper claims that the rate of change in DNA methylation (epigenetic aging) predicts natural lifespan in zebra finches, providing the first evidence of a DNAm-based biological aging marker in birds. This is relevant because it extends the understanding of epigenetic aging mechanisms beyond mammals to a key avian model, offering insights into the generalizability of aging clocks and the impact of early-life environment on biological aging trajectories, though it is a descriptive study rather than an intervention.
Most vertebrates and insects undergo senescence: as they age, their rate of mortality increases while reproduction declines. We present data from a 34-y study on 3,285 colonies of known age in the western harvester ant,
Abstract
Most vertebrates and insects undergo senescence: as they age, their rate of mortality increases while reproduction declines. We present data from a 34-y study on 3,285 colonies of known age in the western harvester ant,
AI-generated longevity analysis. Check claims against the paper.
Summary
The paper demonstrates that the replacement of the queen ant's body (soma) by her workers effectively resets her biological age, allowing her to live indefinitely and reproduce without senescence. This is a landmark finding in evolutionary biology and aging research because it provides a natural, empirical example of "negative senescence" and biological rejuvenation, directly challenging the universal assumption that aging is an inevitable, irreversible process in complex multicellular organisms.
Ribophagy plays a critical role in maintaining ribosome quality, yet how ribosomes are marked for autophagic recognition remains poorly understood. Here, we identify the methyltransferase Dot1/DOT1L as a conserved regulator of ribophagy that generates an "eat-me" signal through…
Abstract
Ribophagy plays a critical role in maintaining ribosome quality, yet how ribosomes are marked for autophagic recognition remains poorly understood. Here, we identify the methyltransferase Dot1/DOT1L as a conserved regulator of ribophagy that generates an "eat-me" signal through methylation of Rpl12, thereby regulating ribosome quality. Under nutrient deprivation, Dot1 methylates Rpl12 at K41 and K48 in Saccharomyces cerevisiae, enhancing its interaction with Atg11 and initiating ribophagy through the TOR-Atg1-Rpl12 signaling axis. In mammals, starvation induces partial cytoplasmic translocation of DOT1L, where it colocalizes with and methylates RPL12. In Drosophila, ribosomes incorporating Gpp (the Dot1 homolog)-methylated RpL12 show strong colocalization with the autophagosome marker Atg8a. Flies carrying methylation-deficient RpL12 mutants exhibit impaired ribophagy, developmental abnormalities, accelerated aging, muscle degeneration, and reduced stress resistance. Collectively, these findings reveal that Dot1-mediated Rpl12 methylation generates a conserved "eat-me" signal that links nutrient availability to ribosome quality control and lifespan regulation.
AI-generated longevity analysis. Check claims against the paper.
Summary
Dot1-mediated methylation of Rpl12 acts as a conserved "eat-me" signal that initiates ribophagy to maintain ribosome quality and regulate lifespan. This paper is relevant because it identifies a specific molecular mechanism linking nutrient sensing to ribosome quality control, a fundamental process in cellular homeostasis, and demonstrates that defects in this pathway lead to accelerated aging and reduced stress resistance in model organisms, thereby addressing a root cause of aging rather than a symptom.
Aging is a major risk factors for metabolic dysfunction-associated steatotic liver disease (MASLD). However, the mechanisms by which aging disrupts hepatocyte transcriptional networks to drive metabolic dysfunction remain poorly understood. Hepatocyte nuclear factor 4 alpha…
Abstract
Aging is a major risk factors for metabolic dysfunction-associated steatotic liver disease (MASLD). However, the mechanisms by which aging disrupts hepatocyte transcriptional networks to drive metabolic dysfunction remain poorly understood. Hepatocyte nuclear factor 4 alpha (HNF4) is a master regulator of hepatocyte identity and metabolic homeostasis, but its role in liver aging has not been defined. Here, we perform a comprehensive multi-omic profiling of young and aged mouse livers combined with targeted HNF4 functional studies to define how aging remodels HNF4-dependent gene regulation and whether HNF4 can be a target to reverse age-associated liver dysfunction. Despite preserved HNF4 expression with age, aging was associated with reduced HNF4 chromatin occupancy and transcriptional activity, accompanied by epigenetic remodeling, including changes in histone acetylation, chromatin accessibility, and DNA methylation. Integration and comparison of HNF4 CUT&RUN with hepatocyte-specific Hnf4a deletion in young and aged livers identified high-confidence overlapping but distinct young- and old- specific HNF4 target gene networks. In young hepatocytes, HNF4 coordinates two complementary transcriptional programs: activation of genes governing hepatocyte identity, lipid metabolism, and metabolic function, while simultaneously inhibiting alternative developmental, proliferative, and inflammatory programs. Spatial transcriptomic analyses further revealed zone-specific specialization of HNF4-dependent gene programs. Aging selectively disrupted these regulatory networks, resulting in compromised liver identity and metabolic gene programs, de-repression of inflammatory pathways and alternative cellular identity programs and disrupted hepatocyte zonation, consistent with age-dependent lipidomic and metabolic changes, hepatic fat accumulation, and immune infiltration. Hepatocyte-specific Hnf4a deletion in young mice recapitulated key features of liver aging, including impaired hepatocyte identity, metabolic dysfunction, steatosis, inflammatory activation and altered hepatic immune-cell composition, while deletion in aged mice further exacerbated steatosis, inflammation, and hepatic dysfunction. Conversely, hepatocyte-specific HNF4 restoration in aged mice significantly reduced hepatic steatosis and lipid accumulation, restored fatty acid metabolic programs, and partially reversed age-associated transcriptional changes. However, inflammatory and interferon-associated programs were not uniformly reversed, revealing differential responsiveness of metabolic and inflammatory pathways to HNF4 restoration. Together, these findings identify age-associated impairment of HNF4 activity as a functional contributor to liver aging, linking dysregulation of hepatocyte identity, metabolic homeostasis, and inflammatory control to age-associated hepatic dysfunction. Importantly, the selective reversibility of metabolic defects following HNF4 restoration establishes HNF4 as a promising strategy for preserving hepatocyte homeostasis and reversing age-associated hepatic metabolic dysfunction.
AI-generated longevity analysis. Check claims against the paper.
Summary
The paper claims that age-associated repression of HNF4α activity is a causal driver of liver metabolic dysfunction and that restoring HNF4 activity can reverse these age-related defects. This is relevant to longevity research because it identifies a specific molecular mechanism (transcriptional dysregulation of a master regulator) that contributes to the physiological decline of a major organ with age, and demonstrates that intervening on this pathway can restore function, thereby addressing a root cause of age-related organ failure rather than just treating symptoms.
Cellular senescence, a hallmark of aging, is accompanied by a striking expansion of the cell's lysosomal compartment, yet the pathway leading to increased lysosomal content remains unresolved. Here, we demonstrate that the master lysosomal transcriptional regulator TFEB is…
Abstract
Cellular senescence, a hallmark of aging, is accompanied by a striking expansion of the cell's lysosomal compartment, yet the pathway leading to increased lysosomal content remains unresolved. Here, we demonstrate that the master lysosomal transcriptional regulator TFEB is activated during senescence through a pathway that involves conjugation of ATG8 onto single membranes (CASM). Using various senescence inducers, we show that senescence induction triggers robust TFEB nuclear translocation and upregulation of TFEB target genes. In contrast, inhibition of the core CASM machinery by CRISPR-mediated deletion of either ATG16L1, ATG12, or ATG5 markedly reduced senescence-induced TFEB nuclear translocation. In ATG16L1-KO cells, reconstitution with WT ATG16L1 but not the CASM-defective ATG16L1F467A mutant restored both ATG8 lipidation on the lysosomal surface and TFEB activation. Moreover, expression of the Salmonella effector protein SopF, a previously described specific CASM inhibitor, similarly blocked senescence-induced TFEB translocation. Functionally, upon stress, CASM-deficient cells exhibited a pronounced shift away from senescence and toward a cell death fate, a phenotype reversed by expressing a constitutively active form of TFEB. Together, these findings identify CASM-dependent TFEB activation as an essential mechanism enabling senescence-associated lysosomal expansion and suggest that lysosomal capacity modulates cell fate decisions in the aftermath of acute stress.
AI-generated longevity analysis. Check claims against the paper.
Summary
CASM-dependent TFEB activation is an essential mechanism enabling senescence-associated lysosomal expansion and modulates cell fate decisions. This paper identifies a specific molecular pathway (CASM) that drives a key cellular hallmark of aging (lysosomal expansion in senescent cells), providing a mechanistic insight into how cells manage stress and decide between senescence and death, which is fundamental to understanding the biology of aging.
Protein aggregation and altered protein solubility indicate proteostatic decline, yet their roles in skeletal muscle aging remain poorly understood. We combined light and electron microscopy, quantitative proteomics, and stable-isotope labeling of skeletal muscle to investigate…
Abstract
Protein aggregation and altered protein solubility indicate proteostatic decline, yet their roles in skeletal muscle aging remain poorly understood. We combined light and electron microscopy, quantitative proteomics, and stable-isotope labeling of skeletal muscle to investigate age-associated changes in protein insolubility, and their responses to exercise and rapamycin. Aged muscle accumulated distinct aggresome and amyloid-positive aggregates despite unchanged bulk insoluble protein content. Instead, aging altered the abundance and soluble-insoluble shifts of lower-abundance proteins across cellular components, particularly mitochondrial, nuclear and extracellular matrix proteins, with greater changes in females. These changes were not broadly explained by intrinsic protein aggregation propensity. Exercise and rapamycin partially reversed age-associated changes in abundance and partitioning without increasing protein synthesis. Together, these findings highlight sex- and cellular component-dependent changes in protein insolubility as important, modifiable aspects of skeletal muscle proteostasis, and indicate that proteostatic maintenance may be a more important target than anabolism for muscle aging.
AI-generated longevity analysis. Check claims against the paper.
Summary
The paper claims that aging-driven skeletal muscle protein insolubility is compartment-specific and modifiable by proteostasis-directed treatments like exercise and rapamycin. This is relevant because it identifies a specific mechanistic driver of muscle aging (proteostatic decline) and demonstrates that interventions targeting protein quality control, rather than just muscle mass, can mitigate age-related physiological changes, offering a potential strategy for extending healthspan.
Non-human primates are an ideal model for interrogating the genetic basis of human lifespan and resilience due to their long lifespan compared to other model organisms, development of similar age-related chronic conditions, and genetic similarity. However, like humans…
Abstract
Non-human primates are an ideal model for interrogating the genetic basis of human lifespan and resilience due to their long lifespan compared to other model organisms, development of similar age-related chronic conditions, and genetic similarity. However, like humans, statistical methods for modeling survival suffer from the challenges of dealing with non-proportionality of hazards, large numbers of living individuals that must be censored, and loss-to-follow-up over studies that may last a decade or more. Here we overcome these challenges through the use of pseudo-observations of Restricted Mean Survival Time as a measure of resilience to the acute challenge of radiation exposure and chronic challenges of aging and a Western-style diet in rhesus macaques (Macaca mulatta) from the Wake Forest Non-Human Primate Radiation Late Effects Cohort. Our whole-exome analysis used Genome-wide Efficient Mixed Model Association (GEMMA) to identify variants associated with longevity, and a subsequent Gene Set Enrichment Analysis (GSEA) highlighted the cadherin and integrin signaling pathways as central to this resilience. As dysregulation of cell adhesion and extracellular matrix signaling is central to the development of fibrosis, we tested the functional relevance of these signals using a targeted Combined Annotation Dependent Depletion (CADD) score-weighted Sequence Kernel Association Test-Optimal (SKAT-O) analysis of GSEA leading-edge genes from both the cadherin and integrin pathways. This linked variant burden in PCDHGA5, PCDHGA3, PCDHGB2, PCDHA11, and PSENEN to the severity of myocardial fibrosis, and in IBSP, PDGFD, and LAMC2 to the severity of pulmonary fibrosis observed at necropsy. Critically, we note that the genetic variants are not caused by the radiation but rather create an underlying risk for disease that is then exacerbated by the acute and persistent stressors challenging these animals' intrinsic resilience. The success of this method in identifying biologically relevant genetic variants underlying survival in animals undergoing a strong challenge to their resilience highlights not only the role of genes predisposing animals to fibrosis in lifespan, but the overall utility of pseudo-observations in overcoming the limitations of survival analyses in humans and other long-lived species.
AI-generated longevity analysis. Check claims against the paper.
Summary
The paper claims that using pseudo-observations of Restricted Mean Survival Time in rhesus macaques identifies specific genetic variants in cadherin and integrin pathways that predispose individuals to fibrosis and reduced resilience to aging and radiation stress. This is relevant because it identifies specific genetic mechanisms underlying intrinsic resilience and lifespan in a non-human primate model, offering potential targets for understanding the genetic basis of healthy aging, though the impact is limited by the specific context of radiation exposure and the use of a single cohort.
Cellular senescence acts as a core driver of chronic diseases and tissue degeneration. Conventional small-molecule senolytics face critical limitations including poor target specificity and off-target toxicity when eliminating heterogeneous senescent cell populations. This…
Abstract
Cellular senescence acts as a core driver of chronic diseases and tissue degeneration. Conventional small-molecule senolytics face critical limitations including poor target specificity and off-target toxicity when eliminating heterogeneous senescent cell populations. This review systematically discusses senescence-targeted engineered chimeric antigen receptor (CAR)-T immunotherapy, which achieves targeted clearance of pathological senescent cells by recognising specific surface markers. It summarises target-antigen evaluation frameworks, analyzes aged immunosuppressive microenvironment barriers and corresponding engineering strategies, and outlines composite efficacy assessment systems and tiered biomarker-monitoring workflows. Key translational bottlenecks such as imperfect antigen specificity and immune escape are also addressed. Preclinical studies verify organ function restoration and healthspan extension, while clinical evidence remains limited. Future integration of CAR-T technology with smart nanocarriers, synthetic biology and artificial intelligence will promote its clinical translation for senescence-associated disorders.
AI-generated longevity analysis. Check claims against the paper.
Summary
This review evaluates the potential of engineered CAR-T cells to target and eliminate senescent cells, a core driver of aging, as an alternative to small-molecule senolytics. The paper is relevant because it addresses the root cause of aging (cellular senescence) by proposing a novel immunotherapeutic mechanism to clear senescent cells, although it is a review of preclinical advances rather than a primary breakthrough study.
The gut microbiota-derived metabolite trimethylamine N-oxide (TMAO) is an established risk factor for cardiovascular and renal diseases, yet its role in driving kidney aging remains poorly defined. Circular RNAs (circRNAs) have emerged as critical regulators of cellular…
Abstract
The gut microbiota-derived metabolite trimethylamine N-oxide (TMAO) is an established risk factor for cardiovascular and renal diseases, yet its role in driving kidney aging remains poorly defined. Circular RNAs (circRNAs) have emerged as critical regulators of cellular senescence, but their integration with systemic metabolic cues in aging processes is largely unknown. Here, we identify a novel signaling axis through which TMAO accelerates renal senescence by dysregulating a specific circRNA pathway. We demonstrate that TMAO treatment induces a senescent phenotype in renal tubular epithelial cells and promotes kidney aging in mice, as evidenced by increased senescence-associated β-galactosidase activity and elevated expression of p53, p21, and p16. Mechanistically, TMAO significantly upregulates the expression of circVmn2r1, a circRNA we previously identified as a key promoter of kidney aging. This upregulation triggers the activation of the the nucleotide-binding domain, leucine-rich repeat-containing family, pyrin domain-containing 3 (NLRP3) inflammasome, leading to increased caspase-1 cleavage and elevated levels of the pro-inflammatory cytokines pro-IL-1β and pro-IL-18. Crucially, genetic knockdown of circVmn2r1
AI-generated longevity analysis. Check claims against the paper.
Summary
TMAO accelerates renal tubular epithelial cell senescence by upregulating circVmn2r1, which activates the NLRP3 inflammasome. This paper is relevant because it identifies a specific molecular mechanism (TMAO-circVmn2r1-NLRP3) linking a systemic metabolic factor to the fundamental process of cellular senescence in the kidney, offering a potential target for intervening in age-related renal decline rather than just treating symptoms.
How diet shapes aging and age-related diseases marked by senescent cell accumulation remains unclear. Here we report vanadyl sulfate (VS), a mineral dietary supplement, as a senolytic agent. Oral VS ameliorates phenotypes of aging and diverse age-related disorders and extends…
Abstract
How diet shapes aging and age-related diseases marked by senescent cell accumulation remains unclear. Here we report vanadyl sulfate (VS), a mineral dietary supplement, as a senolytic agent. Oral VS ameliorates phenotypes of aging and diverse age-related disorders and extends lifespan in male mice. Integrated functional omics analyses show that senescent cells exhibit globally reduced proteome cysteine reactivity but increased expression and apparent cysteine reactivity of proteins essential for endoplasmic reticulum proteostasis. This redox-proteostasis state is linked to glutathione disulfide (GSSG) accumulation and can be recapitulated by GSSG delivery in nonsenescent cells. Mechanistically, VS inactivates reactive cysteines and promotes disulfide bond formation in senescent cells, leading to protein misfolding, aggregation and ultimately cell death. Glutathione reductase downregulation promotes GSSG accumulation, distinguishing senescent from nonsenescent cells and conferring selective susceptibility to VS. Our findings reveal an exploitable redox-proteostasis vulnerability of senescent cells with therapeutic potential to ameliorate aging.
AI-generated longevity analysis. Check claims against the paper.
Summary
Vanadyl sulfate acts as a senolytic agent by exploiting a specific redox-proteostasis vulnerability in senescent cells, characterized by glutathione disulfide accumulation and altered cysteine reactivity, to induce cell death and extend lifespan in mice. This paper is relevant because it identifies a novel mechanism for senolysis and demonstrates that a dietary supplement can target the accumulation of senescent cells, a key driver of aging, thereby directly addressing a root cause of age-related decline rather than just treating symptoms.
Nicotinamide Adenine Dinucleotide (NAD) is a critical cellular coenzyme whose decline associates with various chronic and inflammatory diseases. Improved NAD restoration may reduce disease risks and extend healthy lifespan. We report here that certain commensal bacteria…
Abstract
Nicotinamide Adenine Dinucleotide (NAD) is a critical cellular coenzyme whose decline associates with various chronic and inflammatory diseases. Improved NAD restoration may reduce disease risks and extend healthy lifespan. We report here that certain commensal bacteria including specific probiotic species produce (amide-)N-methylnicotinamide (N-MNA), which is a structural isomer of methylnicotinamide, a nicotinamide degradative metabolite. Patients with gut dysbiosis and inflammation show reduced stool N-MNA. Stable isotope tracing revealed that N-MNA can be rapidly taken up and incorporated into NAD redox reactions by intestinal epithelial cells (IECs) and non-IECs of fruit fly, mouse, and human. Genetic and pharmacological analyses suggest that N-MNA is converted to NAD
AI-generated longevity analysis. Check claims against the paper.
Summary
The paper claims that commensal bacteria produce (amide-)N-methylnicotinamide (N-MNA), a metabolite that is rapidly taken up by intestinal cells and converted into NAD, thereby linking gut microbiome composition directly to host NAD+ homeostasis. This is relevant to longevity because NAD+ decline is a fundamental hallmark of aging, and identifying a microbial source for a novel NAD precursor suggests a potential mechanism by which the microbiome influences systemic metabolic aging and offers a new avenue for NAD+ restoration therapies.
Rapamycin, an mTOR inhibitor, continues to be investigated for hypothesized physiological, disease prevention, and longevity benefits, but few studies have been conducted in humans. Using US national organ transplant registry data, one of the largest real-world datasets…
Abstract
Rapamycin, an mTOR inhibitor, continues to be investigated for hypothesized physiological, disease prevention, and longevity benefits, but few studies have been conducted in humans. Using US national organ transplant registry data, one of the largest real-world datasets examining chronic rapamycin exposure in humans, we compared the Kaplan-Meier survival age distribution of 4885 kidney transplant recipients prescribed rapamycin compared to 6589 recipients not prescribed rapamycin. Recipients were followed a median of 11 years and 6443 died during the study period. Propensity score weighting was used to adjust for exposure group differences in age, BMI, diabetes, and 15 other factors. After adjusting for demographic and clinical differences between groups, the median survival age of 64.6 years in the rapamycin group and 64.3 years in the non-rapamycin group were statistically similar (95% confidence interval for median survival age difference -1.6, 2.0 years). In this large cohort of kidney transplant recipients who were alive with a functioning graft at 1 year post-transplant, we did not observe a meaningful improvement in long-term survival with mTOR inhibition.
AI-generated longevity analysis. Check claims against the paper.
Summary
The paper claims that chronic rapamycin exposure does not provide a meaningful improvement in long-term survival in kidney transplant recipients. This is relevant because rapamycin is a leading candidate for human lifespan extension, and this large-scale real-world study provides critical negative evidence regarding its efficacy in a specific human population, directly impacting the field's understanding of mTOR inhibition's potential for longevity.
Biological aging is complex and resists any single mechanistic narrative. This article develops a conceptual framework for aging biology through a series of brief statements on central topics in the field, with the goal of discussing aging simply, directly and accessibly. The…
Abstract
Biological aging is complex and resists any single mechanistic narrative. This article develops a conceptual framework for aging biology through a series of brief statements on central topics in the field, with the goal of discussing aging simply, directly and accessibly. The organizing principle is that aging is a default outcome of living: because biological processes are inherently imperfect, deleterious changes (the deleteriome) accumulate over time and progressively erode functional reserve. The deleteriome provides a unifying framework for molecular damage, regulatory drift, maladaptive remodeling, and system-level failure, without reducing aging to individual genes, pathways, compartments, hallmarks, or pathologies. Evolution does not program aging; it shapes maintenance and renewal systems that oppose this trajectory with limited fidelity and unavoidable trade-offs. Aging begins during development, following an early embryonic phase of rejuvenation. Modern biomarkers make biological age imperfectly but increasingly measurable. Biological age is heterogeneous across cells, organs, and systems, modifiable by interventions and environment, and in some contexts partially reversible or resettable, although aging itself is irreversible. This model links first principles of aging to measurement, intervention, and longer-term strategies, with the goal of clarifying how substantial longevity gains might be achieved, both within and beyond existing species-level constraints.
AI-generated longevity analysis. Check claims against the paper.
Summary
The paper proposes that aging is a default outcome of living driven by the accumulation of a "deleteriome" of imperfect biological processes, rather than a programmed event. This is a conceptual review that synthesizes existing knowledge into a unified framework, offering a clear perspective on the inevitability of aging and the limits of intervention, but it does not present new experimental data or a novel mechanistic discovery.
Gut microbiota dysbiosis caused by a high-fat diet disrupts hematopoietic stem cell (HSC) homeostasis; however, the underlying mechanisms remain unclear. Here, we identify gut microbial secondary bile acid deoxycholic acid (DCA) as a key mediator of HSC dysfunction in mice…
Abstract
Gut microbiota dysbiosis caused by a high-fat diet disrupts hematopoietic stem cell (HSC) homeostasis; however, the underlying mechanisms remain unclear. Here, we identify gut microbial secondary bile acid deoxycholic acid (DCA) as a key mediator of HSC dysfunction in mice. Plasma DCA levels were elevated during aging, consistent with previously reported increases in high-fat diet-fed mice. Chronic DCA administration upregulated Spred1 in mouse HSCs, as also observed during aging, contributing to HSC loss. DCA treatment in Spred1-deficient mice triggered myeloproliferative neoplasm-like disease, highlighting Spred1's role in mediating a trade-off between HSC aging and tumor suppression. Unexpectedly, DCA-counteracting ursodeoxycholic acid also promoted age-associated expansion of myeloid-biased mouse HSCs. In contrast, a high-fiber diet lowered plasma DCA levels and mitigated aging-associated HSC decline. Our findings reveal that systemic gut microbial metabolites, particularly secondary bile acids, critically affect HSC fate, and suggest that dietary interventions targeting the gut microbiota can regulate hematopoietic homeostasis.
AI-generated longevity analysis. Check claims against the paper.
Summary
The paper claims that gut microbial secondary bile acid deoxycholic acid (DCA) disrupts hematopoietic stem cell homeostasis by upregulating Spred1, linking dietary interventions to the mitigation of age-associated HSC decline. This is relevant to longevity because it identifies a specific, modifiable systemic mechanism (dietary fiber affecting gut metabolites) that directly influences a fundamental aspect of biological aging (stem cell exhaustion and immune aging), rather than merely treating a downstream symptom.
Hematopoietic aging is marked by declining regenerative capacity and a shift from lymphoid to myeloid output. Previous studies have focused primarily on hematopoietic stem cells (HSCs), yet whether aging uniformly remodels the hematopoietic stem and progenitor cell (HSPC)…
Abstract
Hematopoietic aging is marked by declining regenerative capacity and a shift from lymphoid to myeloid output. Previous studies have focused primarily on hematopoietic stem cells (HSCs), yet whether aging uniformly remodels the hematopoietic stem and progenitor cell (HSPC) compartment, or selectively affects distinct populations, remains largely unknown. To address this, we profile HSCs and multipotent progenitors MPP1-6 from young and aged mice across transcriptomic, epigenomic, metabolomic and lipidomic layers, together with single-cell division and in vivo serial transplantation assays. We identify young MPP6 (negative for CD150, CD34, CD48 and CD135) as an HSC-like, lymphoid-biased population with long-term reconstitution capacity, positioned within the top-tier of the differentiation hierarchy and marked by low global chromatin accessibility and metabolic activity. Upon aging, MPP6 preserved long-term lymphoid reconstitution, underwent limited transcriptional and regulatory remodeling, and did not accumulate polyunsaturated phospholipids or show mitochondrial oxidation. By contrast, most HSPCs, and particularly HSCs, underwent pronounced age-associated changes, including myeloid-biased expansion, metabolic rewiring, extensive distal regulatory alteration and accumulation of long-chain polyunsaturated phospholipids linked to increased oxidative stress. Pseudotime analysis further resolved the aged MPP6 compartment into two subsets, including a dormant, lymphoid-biased Dlk1-expressing population characterized by reduced mitochondrial activity, which was distinctly affected by inflammatory challenge in vivo. Together, these findings establish MPP6 as a comparatively resilient population within the aged HSPC compartment and suggest that it may represent a potential target for restoring hematopoietic balance.
AI-generated longevity analysis. Check claims against the paper.
Summary
The paper claims that the MPP6 multipotent progenitor population is uniquely resilient to age-associated remodeling compared to HSCs, preserving lymphoid reconstitution capacity. This is relevant to longevity research because it identifies a specific cellular compartment that retains regenerative potential in aged hematopoiesis, offering a mechanistic insight into why aging is not uniform across stem cell lineages and suggesting a potential target for restoring hematopoietic balance, though it remains a descriptive study in mice without direct interventions to extend lifespan.
The Mexican cavefish, Astyanax mexicanus, is a powerful evolutionary model for investigating how adaptation to extreme environments reshapes vertebrate physiology. Multiple cave populations have independently evolved under subterranean conditions, acquiring traits including…
Abstract
The Mexican cavefish, Astyanax mexicanus, is a powerful evolutionary model for investigating how adaptation to extreme environments reshapes vertebrate physiology. Multiple cave populations have independently evolved under subterranean conditions, acquiring traits including insulin resistance, persistent hyperglycaemia, increased adiposity, altered sleep patterns, hypoxia tolerance and extensive metabolic reprogramming. Despite these differences, cavefish exhibit lifespans comparable to those of surface fish, while selected traits, including fertility and locomotor performance, appear to be better preserved with age. These observations challenge the assumption that persistent metabolic dysfunction necessarily entails accelerated functional decline and raise the possibility that cavefish have evolved mechanisms of ageing resilience. This narrative review examines evidence linking cave adaptation to biological processes relevant to ageing, focusing on nutrient sensing, lipid metabolism, mitochondrial function, redox homeostasis and immune regulation. Rather than eliminating metabolic stress, cave-associated adaptations may buffer some of its downstream consequences, preserving selected physiological functions. Evidence is evaluated within the framework of the hallmarks of ageing, considering genomic instability, telomere dynamics, deregulated nutrient sensing, mitochondrial dysfunction and chronic inflammation, while identifying major knowledge gaps regarding epigenetic alterations, loss of proteostasis, macroautophagy, cellular senescence, stem-cell exhaustion, altered intercellular communication and dysbiosis. The available evidence supports A. mexicanus as a comparative model for investigating how chronic environmental and metabolic stress can be uncoupled from selected aspects of functional decline. Distinguishing delayed ageing from enhanced tolerance or compensation in response to accumulated damage will be essential to establish the extent and mechanisms of ageing resilience in this species.
AI-generated longevity analysis. Check claims against the paper.
Summary
The paper proposes that cavefish have evolved mechanisms of ageing resilience that buffer the downstream consequences of chronic metabolic stress, thereby preserving selected physiological functions despite persistent metabolic dysfunction. This is a narrative review that synthesizes existing evidence on a comparative model organism to explore the uncoupling of metabolic stress from functional decline, offering a conceptual framework for understanding ageing resilience rather than presenting new experimental data or a direct intervention strategy.
Stresses occurring transiently and early in life can have long-standing consequences for health, even long after the stress has resolved. Many environmental stressors converge on activating the integrated stress response (ISR), whose major effector is ATF4. However, it remains…
Abstract
Stresses occurring transiently and early in life can have long-standing consequences for health, even long after the stress has resolved. Many environmental stressors converge on activating the integrated stress response (ISR), whose major effector is ATF4. However, it remains unknown whether transient ATF4-ISR activation early in life is a mediator of life and healthspan. Here we used inducible, reversible ATF4 gain-of-function in Drosophila to determine how the timing, duration and tissue of ATF4 activation determine ageing outcomes. We found that ATF4 induction confined to early adulthood extended healthspan, reducing mortality risk by approximately 50% across all ages and improving neuromuscular function in aged flies. Multi-organ transcriptomics showed that the acute ATF4 transcriptional response was transient, as expected, but replaced by a distinct, secondary transcriptional programme of metabolic remodelling that was associated with decreased total body protein content. By using tissue-specific ATF4 induction, we found that transient ATF4 activation in neurons was sufficient to extend lifespan, slow age-related locomotor decline and increase starvation resistance in old age. This neuron-restricted activation prevented the costs to body weight and fecundity induced by ubiquitous ATF4 activation. Transient neuronal ATF4 left a lasting non-autonomous imprint on the fat body at old age: induction of heterochromatin genes, reduced transposable element expression, and increased mitochondrial respiratory capacity. These findings show that the duration and tissue of ISR-ATF4 activation are the key determinants of ATF4 actions that promote healthy ageing, while revealing a brain-to-fat body axis initiated by neuronal ATF4 that results in lasting systemic adaptation.
AI-generated longevity analysis. Check claims against the paper.
Summary
A transient pulse of neuronal ATF4 activation in early adulthood installs a durable, non-autonomous transcriptional and metabolic programme in the fat body that extends lifespan and healthspan. This is highly relevant because it identifies a specific, transient, and tissue-restricted intervention (neuronal ISR activation) that bypasses the typical metabolic costs of systemic stress responses to produce long-term systemic adaptation and healthy aging, offering a precise mechanistic target for longevity research.
Telomeric repeat-containing RNA (TERRA) has long been viewed as a constitutive component of telomeres. However, accumulating experimental evidence suggests that TERRA is instead a stress-responsive signal produced specifically at dysfunctional telomeres. Across yeasts and…
Abstract
Telomeric repeat-containing RNA (TERRA) has long been viewed as a constitutive component of telomeres. However, accumulating experimental evidence suggests that TERRA is instead a stress-responsive signal produced specifically at dysfunctional telomeres. Across yeasts and mammals, TERRA abundance changes as telomeres shorten or become damaged, engaging the appropriate maintenance pathway through interactions with shelterin, chromatin regulators and DNA repair factors, and through the controlled formation of RNA:DNA hybrids (R-loops). In telomerase-negative cells, transient accumulation of TERRA and R-loops promotes homology-directed telomere elongation. In telomerase-positive cells, TERRA appears to direct telomerase activity selectively toward short telomeres. When telomere damage remains unresolved, sustained TERRA expression and persistent R-loops drive cells toward senescence, inflammatory signaling and crisis-associated cell death. We propose here that TERRA functions as a molecular rheostat at damaged telomeres: transient and spatially controlled induction restores chromosome-end integrity, whereas persistent accumulation results in the removal of compromised cells from the proliferative pool. Defining how cells set these switch points will be essential for elucidating how TERRA shapes ageing and disease and for harnessing its therapeutic potential.
AI-generated longevity analysis. Check claims against the paper.
Summary
The paper proposes that TERRA functions as a molecular rheostat where transient induction restores telomere integrity while persistent accumulation drives senescence and cell death. This is relevant to longevity because it identifies a specific molecular mechanism governing the transition from cellular maintenance to aging-associated senescence, offering potential targets for intervening in the fundamental processes of cellular aging.
How progenitor cells couple their metabolic state to the regulation of fate and differentiation remains a fundamental question in tissue development and regeneration. Here, we identify a nutrient-responsive circuit that links progenitor anabolism to differentiation in the…
Abstract
How progenitor cells couple their metabolic state to the regulation of fate and differentiation remains a fundamental question in tissue development and regeneration. Here, we identify a nutrient-responsive circuit that links progenitor anabolism to differentiation in the Drosophila midgut. We show that the mTORC1 downstream effector PWP1 is necessary and sufficient for differentiation of intestinal stem cell progeny toward the absorptive lineage in fed animals. In progenitors with high mTORC1 activity, PWP1 controls gene expression to promote Hedgehog (Hh) signaling, which cell autonomously drives progenitor differentiation into enterocytes. This circuit is constrained by feedback regulation, as elevated Hh activity inhibits mTORC1 and consequently excludes PWP1 from the nucleus. Disruption of the mTORC1-PWP1-Hh axis causes a progressive failure of enterocyte turnover during aging and reduced lifespan. While the aged midguts retain their barrier function, defective renewal leads to aging-associated deregulation of intestinal metabolism. Collectively, these observations support the concept of growth-dependent licensing of differentiation, whereby the nutrient-responsive anabolic state of a progenitor cell controls its lineage progression, consequently enabling organ renewal.
AI-generated longevity analysis. Check claims against the paper.
Summary
The paper demonstrates that the mTORC1-PWP1-Hedgehog signaling axis is required for nutrient-responsive intestinal stem cell differentiation and that its disruption leads to reduced lifespan in Drosophila. This is relevant because it identifies a specific molecular mechanism linking nutrient sensing to tissue renewal and lifespan, providing a potential target for interventions aimed at maintaining organ homeostasis during aging.
Microbial diets and their metabolites can influence host aging, yet identifying geroprotective compounds from complex culture matrices remains challenging. Here, a diet supplemented with the human gut-derived Enterococcus faecium SI194 extended the mean lifespan of…
Abstract
Microbial diets and their metabolites can influence host aging, yet identifying geroprotective compounds from complex culture matrices remains challenging. Here, a diet supplemented with the human gut-derived Enterococcus faecium SI194 extended the mean lifespan of Caenorhabditis elegans by 23.24%, improved aging-associated phenotypes, and enhanced SKN-1-responsive signaling. No lifespan extension was detected in skn-1(zu67) mutants, consistent with the involvement of SKN-1. To prioritize metabolites for independent phenotypic evaluation, we integrated untargeted metabolomics with structure-based virtual screening against glycogen synthase kinase-3 (GSK-3), a negative regulator of SKN-1. Among 71 structurally annotated features enriched in the OP50-SI194 liquid-culture preparation, the feature annotated as obtusifolin had the most favorable Vina docking score. A single 100-ns molecular dynamics trajectory supported the conformational persistence of the modeled GSK-3-Obt complex under the simulated conditions. Exogenous obtusifolin (Obt; 30μM) extended mean lifespan by 14.55%, reduced DCFH-DA-derived fluorescence and age-associated intestinal autofluorescence, and increased gst-4p::GFP fluorescence. These findings support the geroprotective effects of the SI194-supplemented diet and exogenous Obt as distinct interventions and illustrate the workflow's utility for candidate prioritization. Future studies should clarify Obt's contribution to SI194-associated lifespan extension and its relationship with SKN-1 and GSK-3.
AI-generated longevity analysis. Check claims against the paper.
Summary
Obtusifolin, a metabolite identified via metabolomics-guided virtual screening, extends C. elegans lifespan by 14.55% through SKN-1-dependent pathways. This is a solid but incremental study that validates a specific workflow for identifying geroprotectors from microbial diets, offering a modest contribution to the field of dietary geroprotection without providing a novel mechanism or transformative breakthrough.