Longevity Papers

Clonal hematopoiesis (CH) is characterized by expanding blood cell clones carrying somatic mutations in healthy aged individuals and is associated with various age-related diseases and all-cause mortality. While CH mutations affect diverse genes associated with myeloid malignancies, their mechanisms of expansion and disease associations remain poorly understood. We investigate the relationship between clonal fitness and clinical outcomes by integrating data from three longitudinal aging cohorts (n=713, observations=2,341). We demonstrate pathway-specific fitness advantage and clonal composition influence clonal dynamics. Further, the timing of mutation acquisition is necessary to determine the extent of clonal expansion reached during the host individual\'s lifetime. We introduce MACS120, a metric combining mutation context, timing, and variant fitness to predict future clonal growth, outperforming traditional variant allele frequency measurements in predicting clinical outcomes. Our unified analytical framework enables standardized clonal dynamics inference across cohorts, advancing our ability to predict and potentially intervene in CH-related pathologies.

Aging is the primary risk factor for most neurodegenerative diseases, yet the cell-type-specific progression of brain aging remains poorly understood. Here, we developed human cell-type-specific transcriptomic aging clocks using high-quality single-nucleus RNA sequencing data from post mortem human prefrontal cortex tissue of 31 donors aged 18-94 years, encompassing 73,941 high-quality nuclei. We observed distinct transcriptomic changes across major cell types, including upregulation of inflammatory response genes in microglia from older samples. Aging clocks trained on each major cell type accurately predicted chronological age and remained robust in independent single-nucleus RNA-sequencing datasets, underscoring their broad applicability. These findings demonstrate the feasibility of cell-type-specific transcriptomic clocks to measure biological aging in the human brain and highlight potential mechanisms of selective vulnerability in neurodegenerative diseases. We anticipate these clocks will serve as a basis for further studies in other brain regions and more diverse populations, ultimately advancing our understanding of age-related neurodegenerative processes at the single-cell level.

Recent evidence indicates that the organization of the human neocortex is underpinned by smooth spatial gradients of functional connectivity (FC). These gradients provide crucial insight into the relationship between the brain's topographic organization and the texture of human cognition. However, no studies to date have charted how intrinsic FC gradient architecture develops across the entire human lifespan. In this work, we model developmental trajectories of the three primary gradients of FC using a large, high-quality, and temporally-dense functional MRI dataset spanning from birth to 100 years of age. The gradient axes, denoted as sensorimotor-association (SA), visual-somatosensory (VS), and modulation-representation (MR), encode crucial hierarchical organizing principles of the brain in development and aging. By tracking their development throughout the human lifespan, we provide the first ever comprehensive low-dimensional normative reference of global FC hierarchical architecture. We observe significant age-related changes in global network features, with global markers of hierarchical organization increasing from birth to early adulthood and decreasing thereafter. During infancy and early childhood, FC organization is shaped by primary sensory processing, dense short-range connectivity, and immature association and control hierarchies. Functional differentiation of transmodal systems supported by long-range coupling drives a convergence toward adult-like FC organization during late childhood, while adolescence and early adulthood are marked by the expansion and refinement of SA and MR hierarchies. While gradient topographies remain stable during late adulthood and aging, we observe decreases in global gradient measures of FC differentiation and complexity from 30 to 100 years. Examining cortical microstructure gradients alongside our functional gradients, we observed that structure-function gradient coupling undergoes differential lifespan trajectories across multiple gradient axes.

Alzheimer\'s disease (AD) risk and progression are significantly influenced by APOE genotype with APOE4 increasing and APOE2 decreasing susceptibility compared to APOE3. While the effect of those genotypes was extensively studied on blood metabolome, less is known about their impact in the brain. Here we investigated the impacts of APOE genotypes and aging on brain metabolic profiles across the lifespan, using human APOE-targeted replacement mice. Biocrates P180 targeted metabolomics platform was used to measure a broad range of metabolites probing various metabolic processes. In all genotypes investigated we report changes in acylcarnitines, biogenic amines, amino acids, phospholipids and sphingomyelins during aging. The decreased ratio of medium to long-chain acylcarnitine suggests a reduced level of fatty acid {beta}-oxidation and thus the possibility of mitochondrial dysfunction as these animals age. Additionally, aging APOE2/2 mice had altered branch-chain amino acids (BCAA) profile and increased their downstream metabolite C5 acylcarnitine, indicating increased branched-chain amino acid utilization in TCA cycle and better energetic profile endowed by this protective genotype. We compared these results with human dorsolateral prefrontal cortex metabolomic data from the Religious Orders Study/Memory and Aging Project, and we found that the carriers of APOE2/3 genotype had lower markers of impaired BCAA katabolism, including tiglyl carnitine, methylmalonate and 3-methylglutaconate. In summary, these results suggest a potential involvement of the APOE2 genotype in BCAA utilization in the TCA cycle and nominate these humanized APOE mouse models for further study of APOE in AD, brain aging, and brain BCAA utilization for energy. We have previously shown lower plasma BCAA to be associated with incident dementia, and their higher levels in brain with AD pathology and cognitive impairment. Those findings together with our current results could potentially explain the AD-protective effect of APOE2 genotype by enabling higher utilization of BCAA for energy during the decline of fatty acid {beta}-oxidation.

Our previous research suggested that mechanistic target of rapamycin (mTOR)/blood-testis barrier (BTB) mechanism is involved in the regulation of the rates of epigenetic aging of sperm, where increased activity of mTORC1 opens BTB and accelerates epigenetic aging and increased activity of mTORC2 produces opposite results - increases BTB integrity and rejuvenates sperm epigenome. In the present study, we use our newly developed epigenetic clock model to investigate whether the mTOR/BTB mechanism is involved in the epigenetic reprogramming of sperm in mice exposed to heat stress (HS) and cadmium (Cd). Our findings show that both mTOR-dependent BTB disruption caused by HS and mTOR-independent BTB disruption due to Cd exposure accelerate sperm epigenetic aging, resulting in similar changes to sperm DNA methylation patterns. These results suggest that the mTOR/BTB mechanism is a novel molecular pathway through which environmental stressors influence sperm epigenetic aging, and this pathway may be relevant to a broad range of factors, including environmental, lifestyle, dietary, and health influences.

The choroid plexus (CP) plays a critical role in maintaining central nervous system (CNS) homeostasis, producing cerebrospinal fluid, and regulating the entry of specific substances into the CNS from blood. CP dysfunction has been implicated in various neurological and psychiatric disorders, including Alzheimer's disease, Parkinson's disease, and multiple sclerosis. This study investigates the relationship between CP structural integrity and cognitive decline in normative aging, using structural and advanced magnetic resonance imaging techniques, including CP volume, diffusion tensor imaging indices (mean diffusivity, MD, and fractional anisotropy, FA) and relaxometry metrics (longitudinal, T1, and transverse, T2, relaxation times). Our results show that diminished CP microstructural integrity, as reflected by higher T1, T2, and MD values, or lower FA values, is associated with lower cognitive performance in processing speed and fluency. Notably, CP microstructural measures demonstrated greater sensitivity to cognitive decline than macrostructural measures, i.e. CP volume. Longitudinal analysis revealed that individuals with reduced CP structural integrity exhibit steeper cognitive decline over time. Furthermore, structural equation modeling revealed that a latent variable representing CP integrity predicts faster overall cognitive decline, with an effect size comparable to that of age. These findings highlight the importance of CP integrity in maintaining cognitive health and suggest that a holistic approach to assessing CP integrity could serve as a sensitive biomarker for early detection of cognitive decline. Further research is needed to elucidate the mechanisms underlying the relationship between CP structural integrity and cognitive decline and to explore the potential therapeutic implications of targeting CP function to prevent or treat age-related cognitive deficits.

Nicotinamide adenine dinucleotide (NAD) and glutathione are vital molecules that control redox-state, enzyme functions and metabolic flux in hundreds of cellular metabolic reactions. High NAD+ level occurs in fasting and has been associated with health outcomes in model systems, while low NAD+/NADH ratio occurs in specific diseases. Still, the normal, booster-treated or disease-related levels of NADs or glutathiones are not well known in humans. Here, we present a standardized technology for high-throughput quantitative measurement of NAD+, NADH, NADP+, NADPH, GSH, and GSSG from a single whole-blood sample. In healthy population (n=299;18-70 year-olds) redox metabolites follow normal distribution in blood and remain unchanged during aging. NAD-boosting increased 4-6 fold the blood NAD+ depending on individual, pointing to need of personalized dose adjustment in treatment trials. In patients with cancer, diabetes or neurodegeneration, NADs and glutathiones showed disease-dependent \'\'redox fingerprints\'\'. The evidence highlights the potential of redox profiling as an indicator of metabolic pathology and as a measure of treatment response.

Aging is a multifaceted process associated with a functional decline in cellular function over time, affecting all lifeforms. During the aging process, metabolism, a fundamental hallmark of life (1), is profoundly altered. In the context of hematopoiesis, the proper function of hematopoietic stem cells - at the apex of the blood system - is tightly linked to their energy metabolism, which in turn shapes hematopoietic output. Here, we review the latest developments in our understanding of the metabolic states and changes in aged hematopoietic stem cells, molecular players and pathways involved in aged hematopoietic stem cell metabolism, the consequences of perturbed metabolism on clonal hematopoiesis and leukemogenesis, and pharmacologic/ genetic strategies to reverse or rejuvenate altered metabolic phenotypes.

Biological ageing is known to vary among different organs within an individual, but the extent to which advanced ageing of specific organs increases the risk of age-related diseases in the same and other organs remains poorly understood.

Age and elevated intraocular pressure (IOP) are the two major risk factors for developing glaucoma, a leading cause of blindness worldwide that is characterized by the loss of retinal ganglion cells (RGCs). Although vision loss is irreversible over the long term, accumulating evidence points to short-term improvement of vision in glaucoma patients in response to certain interventions, suggesting that RGCs have the capacity to recover function. In the present study, we sought to investigate the mechanisms underlying loss and recovery of RGC function in response to aging and IOP injury, with a focus on synaptic connectivity. Using electroretinography, we found that advancing age was associated with a substantial reduction in function across all retinal layers in the absence of significant cell loss. A superimposed injury induced by IOP elevation led to the selective loss of RGC function in young and middle-aged mice that was associated with a decrease in paired excitatory synapses. RGC functional recovery after injury was significantly delayed in middle-aged mice and was mediated through different cellular mechanisms than in young mice. Whereas young mice regained excitatory synaptic inputs from bipolar cells, functional recovery in older mice was instead mediated through an increase in intrinsic RGC excitability, associated with modulation of the action potential threshold and axon initial segment length. Our findings provide new insights into the impact of advancing age on RGC resilience to IOP injury. Boosting the capacity for RGC recovery by reversing the effect of advancing age offers a new therapeutic approach for glaucoma management.

Female reproductive aging is accompanied by a dramatic rise in the incidence of egg aneuploidy. Premature loss of chromosome cohesion proteins and untimely separation of chromosomes is thought to underly high rates egg aneuploidy during maternal aging. However, because chromosome cohesion loss occurs gradually over female reproductive lifespan and cytoskeletal defects alone can predispose eggs to chromosomal abnormalities, the root causes of exponential rise in egg aneuploidy at advanced reproductive ages remain a mystery. Here, we applied high-resolution live imaging to visualize for the first time cohesion protein dynamics underpinning meiotic chromosome segregation. To discover proteins whose dysfunction accelerates aneuploidies associated with female reproductive aging, we innovated the first experimental system in which chemically induced cohesion reduction rapidly triggers aging-like chromosomal abnormalities in young eggs. By integrating this direct cohesion manipulation system with quantitative high-resolution microscopy and targeted protein degradation tools, we identified the centromeric protein CENP-A as a new factor whose aging-like depletion causes a dramatic rise in premature separation of sister chromatids. Our work illuminates cohesion loss-independent origins of age-related egg aneuploidy and provides new avenues to discover therapeutic targets for extending the female reproductive lifespan.

Aging and metabolic disorders share intricate molecular pathways, with the Forkhead box O (FOXO)- Sirtuin 1 (SIRT1) axis emerging as a pivotal regulator of cellular stress adaptation, metabolic homeostasis, and longevity. This axis integrates nutrient signaling with oxidative stress defence, modulating glucose and lipid metabolism, mitochondrial function, and autophagy to maintain cellular stability. FOXO transcription factors, regulated by SIRT1 deacetylation, enhance antioxidant defence mechanisms, activating genes such as superoxide dismutase (SOD) and catalase, thereby counteracting oxidative stress and metabolic dysregulation. Recent evidence highlights the dynamic role of reactive oxygen species (ROS) as secondary messengers in redox signaling, influencing FOXO-SIRT1 activity in metabolic adaptation. Additionally, key redox-sensitive regulators such as nuclear factor erythroid 2-related factor 2 (Nrf2) and Peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) interact with this pathway, orchestrating mitochondrial biogenesis and adaptive stress responses. Pharmacological interventions, including alpha-lipoic acid (ALA), resveratrol, curcumin and NAD

Cardiovascular diseases (CVDs) are experiencing a rapid surge and are widely recognized as the leading cause of mortality in the current aging society. Given the multifactorial etiology of CVDs, understanding the intricate molecular and cellular mechanisms is imperative. Over the past 2 decades, many scientists have focused on Sirtuins, a family of nicotinamide adenine dinucleotide-dependent deacylases. Sirtuins are highly conserved across species, from yeasts to primates, and play a crucial role in linking aging and diseases. Sirtuins participate in nearly all key physiological and pathological processes, ranging from embryogenic development to stress response and aging. Abnormal expression and activity of Sirtuins exist in many aging-related diseases, while their activation has shown efficacy in mitigating these diseases (eg, CVDs). In terms of research, this field has maintained fast, sustained growth in recent years, from fundamental studies to clinical trials. In this review, we present a comprehensive, up-to-date discussion on the biological functions of Sirtuins and their roles in regulating cardiovascular biology and CVDs. Furthermore, we highlight the latest advancements in utilizing Sirtuin-activating compounds and nicotinamide adenine dinucleotide boosters as potential pharmacological targets for preventing and treating CVDs. The key unresolved issues in the field-from the chemicobiological regulation of Sirtuins to Sirtuin-targeted CVD investigations-are also discussed. This timely review could be critical in understanding the updated knowledge of Sirtuin biology in CVDs and facilitating the clinical accessibility of Sirtuin-targeting interventions.

Exercise is one of the most potent interventions known that is able to prevent and even treat dozens of age-related dysfunctions and diseases. Despite this, much remains unknown about how its benefits are derived. Because exercise exerts such wide-ranging effects, and because a decline in protein homeostasis (proteostasis) with age has been connected to numerous age-related diseases, I hypothesized that exercise could increase the activity of proteostasis pathways like the proteasome and autophagy and that this could ameliorate age-related declines in function. I decided to use a Caenorhabditis elegans exercise paradigm to explore the effects exercise has on proteostasis because of its inherent advantages that make it an appealing model organism. Recent studies of involuntary thrashing (swimming) in C. elegans found that it was able to replicate numerous aspects of mammalian exercise, including increased mitochondrial function, increased muscle function, and gene expression profiles that resemble mammalian endurance exercise. I used this thrashing exercise paradigm to look at effects of acute exercise and the effects of multiple days of exercise on aging and proteostasis, including the autophagy-lysosome system, the proteasome, and toxic peptides. I found that exercise is able to increase proteasomal activity and autophagic flux in vivo, improved resistance to toxic peptides, and increased lifespan. One of the primary rationales for studying the mechanisms of exercise is to uncover potential mediators that can be repurposed to deliver the benefits of exercise to those unable to engage in physical activity. I hypothesized that exercise-elevated metabolite alpha-ketoglutarate, already demonstrated to improve age-related declines in flies and mice, would mimic the effects of exercise on proteostasis. Interestingly, treatment with alpha-ketoglutarate showed mixed results on measures of proteostasis, indicative of the challenges in recapitulating a complex phenomenon like exercise.

Trees are long-lived plants that develop complex, highly branched shoot systems as they grow. Their extended lifespan allows somatic mutations to accumulate along these branching structures, ultimately becoming fixed in reproductive and vegetative tissues such as leaves, flowers, and fruits. Mature trees can easily sustain tens of thousands of terminal branches, each potentially carrying mutated gametes. To avoid mutational meltdown and inbreeding depression, long-lived plants appear to have evolved mechanisms that slow mutation accumulation per unit time. How this is achieved remains unclear. Here, we show that branching architecture can limit mutation accumulation to the same extent as reducing the mutation rate itself. Tree structures that maximize branch path sharing during development constrain mutational diversity in the crown. These architectural factors can drive differences in mutation burden by orders of magnitude, even when mutation rates and terminal branch numbers are identical. Building on these insights, we show that current estimates of somatic mutation rates in trees are actually upward biased by a factor that scales with the topological characteristics of the tree. These results raise the deeper question whether somatic mutation rate differences, recently detected among tree species, reflect variation in branching strategies rather than variation in the rates themselves. It is possible that specific branching architectures have evolved not only to optimize resource allocation and structural stability but also to limit mutational load.

Cellular senescence and hypoxia-inducible factor (HIF) signaling are crucial in pulmonary aging and age-related lung diseases such as chronic obstructive pulmonary disease idiopathic pulmonary fibrosis and lung cancer. HIF plays a pivotal role in cellular adaptation to hypoxia, regulating processes like angiogenesis, metabolism, and inflammation. Meanwhile, cellular senescence leads to irreversible cell cycle arrest, triggering the senescence-associated secretory phenotype which contributes to chronic inflammation, tissue remodeling, and fibrosis. Dysregulation of these pathways accelerates lung aging and disease progression by promoting oxidative stress, mitochondrial dysfunction, and epigenetic alterations. Recent studies indicate that HIF and senescence interact at multiple levels, where HIF can both induce and suppress senescence, depending on cellular conditions. While transient HIF activation supports tissue repair and stress resistance, chronic dysregulation exacerbates pulmonary pathologies. Furthermore, emerging evidence suggests that targeting HIF and senescence pathways could offer new therapeutic strategies to mitigate age-related lung diseases. This review explores the intricate crosstalk between these mechanisms, shedding light on how their interplay influences pulmonary aging and disease progression. Additionally, we discuss potential interventions, including senolytic therapies and HIF modulators, that could enhance lung health and longevity.

Perivascular spaces (PVS) play a critical role in fluid transfer and waste clearance in the brain, but few studies have explored how alterations to perivascular fluid flow may impact brain maturation and behavior. This study aims to characterize age-related alterations to perivascular and parenchymal fluid flow characteristics across the lifespan in typically developing children (8-21 years) and aging adults (35-90 years) and assess their contribution to cognition. In this study, we employ multi-compartment diffusion models, neurite orientation dispersion and density imaging (NODDI) and tissue tensor imaging (TTI), to quantify free water diffusion characteristics within automatically defined perivascular spaces using enhanced PVS contrasts, the surrounding parenchyma, and at variable distances from the PVS. Our findings show free water diffusion characteristics within the PVS and surrounding parenchyma are associated with age and cognitive scores.

Aging and pregnancy both involve changes in many physiological systems. Some of these changes are similar, leading to suggestions that pregnancy may be a model for aging. Recent studies using DNA methylation clocks showed apparent aging during gestation which resolves postpartum. Since aging and pregnancy are complex, it is important to compare them in terms of many physiological parameters and at many time points. Here, we analyzed cross-sectional data on 62 lab tests at weekly resolution in 300,000 pregnancies and 1.4 million nonpregnant females aged 20-80. We trained a regression model to predict age from lab tests. Apparent age dropped by 8 years in early pregnancy, rose by 30 years towards delivery, and recovered postpartum. Certain systems exhibited \"rejuvenation,\" with opposite trends in pregnancy and aging, including renal, iron, and most liver tests. Others, such as coagulation, thyroid, muscle, and metabolic systems, showed apparent aging. Some systems displayed mixed trends. Notably, in the systems that showed apparent aging, the physiological mechanisms for the changes differed between pregnancy and aging. Pregnancy complications led to an additional apparent aging of 4-8 years. We conclude that pregnancy is a superficial model of aging that involves different mechanisms and rejuvenation or aging-like changes in different systems. Nevertheless, apparent age may be a convenient way to measure magnitude and direction of physiological perturbations.

The hypothalamus has been recognized as a regulator of whole-body aging. Neuropeptide Y (NPY), highly abundant in the central nervous system and produced by the hypothalamus, enhances autophagy in this brain region and mediates autophagy triggered by caloric restriction, suggesting a potential role as a caloric restriction mimetic and an aging regulator. Considering that hypothalamic NPY levels decline during aging, we investigated if reestablishment of NPY levels mitigate aging phenotype, using a mouse model of premature aging - Zmpste24

Synapse dysfunction is tightly linked to cognitive changes during aging, but underlying mechanisms driving dysfunction are minimally understood. The extracellular matrix (ECM) can potently regulate synapse integrity and plasticity. Yet the status of the brain ECM during aging remains virtually unexplored. Using novel ECM-optimized proteomic workflows, we discovered striking regional differences in ECM composition and aging-induced ECM remodeling. ECM status was also aligned with preserved synapse protein abundance across key basal ganglia nuclei. Moreover, using novel reward-learning paradigms and confocal imaging in fixed tissue, we demonstrated that reduced ECM-synapse remodeling and microglial aging phenotypes, are both linked with deficits in goal-directed behavior in aging mice. Finally, using mouse models of microglia ablation and premature microglial aging, we identified microglial aging phenotypes that promote ECM deposition and synapse numbers. Together, these foundational observations implicate glial-ECM interactions in the regulation of synapse function and cognitive abilities across the lifespan.

Most adults experience age-related cognitive decline. However, "Positive-Agers" exhibit superior cognition compared to their age-matched peers. Distinguishing between those with superior cognitive performance and those with cognitive decline over time could better inform treatment therapies in older adults. We developed an algorithm called Optimal Cognitive Scoring (OptiCS) that accurately differentiates "Positive-Agers" from "Cognitive Decliners." This study draws on a cohort of 5797 participants longitudinally enrolled in the UK Biobank. Using a predictive pipeline, OptiCS could strongly differentiate Positive-Agers versus Cognitive Decliners (area under the curve, or AUC of 83%). The top diffusion MRI attributes highlighted tracts implicated in pathological aging, including the fornix from the hippocampus, the tapetum from the splenium of the corpus callosum, and other key tracts. This study provides three key insights: (I) The proposed algorithm offers a robust cognitive scoring system for subtle cognitive changes, (II) OptiCS can use diffusion MRI to accurately gauge cognitive performance, and (III) OptiCS provides a predictive framework for early detection of cognitive decline.

Temperature profoundly impacts all living organisms, influencing development, growth, longevity, and metabolism. Specifically, when adult flies are exposed to high temperatures, there is a notable reduction in their body fat content. We investigate the roles of the insulin signaling pathway in temperature-mediated fat storage. This pathway is not only highly conserved from insects to mammals but also crucial in regulating lipid metabolism, cell proliferation, and tissue growth. The Forkhead box O (FoxO) protein functions as a key downstream signaling molecule in this pathway, mediating the inhibitory effects of insulin signaling. At elevated temperatures, direct targets of FoxO, such as insulin receptor (InR), Thor (Drosophila eukaryotic initiation factor 4E binding protein), and FoxO itself, are significantly upregulated, which indicates an inhibition of insulin signaling. Interestingly, this inhibition seems to occur independently of Drosophila insulin-like peptide (Ilp) stimuli, as not all Ilp transcripts were reduced at elevated temperatures. Furthermore, when S2R + Drosophila cells are incubated at high temperatures, there is a marked decrease in Akt phosphorylation, directly supporting the notion that elevated temperatures can inhibit insulin signaling in a cell-autonomous manner, independent of Ilp levels. Subsequent experiments demonstrated that either constitutively active InR or knockdown of FoxO prevents the reduction of body fat at high temperatures. Together, these findings highlight the critical role of the insulin signaling-FoxO branch in regulating lipid homeostasis under heat stress conditions.

Decline in ovarian function with age not only affects fertility but is also linked to a higher risk of age-related diseases in women (e.g. osteoporosis, dementia). Intriguingly, earlier menopause is linked to shorter lifespan; however, the underlying molecular mechanisms of ovarian aging are not well understood. Recent evidence suggests the gut microbiota may influence ovarian health. In this study, we characterized ovarian aging associated microbial profiles in mice and investigated the effect of the gut microbiome from young and estropausal female mice on ovarian health through fecal microbiota transplantation. We demonstrate that the ovarian transcriptome can be broadly remodeled after heterochronic microbiota transplantation, with a reduction in inflammation-related gene expression and trends consistent with transcriptional rejuvenation. Consistently, these mice exhibited enhanced ovarian health and increased fertility. Using metagenomics-based causal mediation analyses and serum untargeted metabolomics, we identified candidate microbial species and metabolites that may contribute to the observed effects of fecal microbiota transplantation. Our findings reveal a direct link between the gut microbiota and ovarian health.

Introduction: The aging lung enters into a state of irreversible cellular growth arrest characterized by senescence. While senescence is beneficial in preventing oncogenic cell proliferation, it becomes detrimental when persistent, promoting chronic inflammation and fibrosis through the senescence-associated secretory phenotype (SASP). Such senescence-related pathophysiological processes play key roles in lung diseases like chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF). However, few models accurately represent senescence in the human lung. Methods: To generate a human lung senescence in vitro model, we first generated a human induced pluripotent stem cell (hiPSC)-derived lung organoid (LO) system which was dissociated into monolayers and air-liquid interface (ALI) cultures to enhance visualization and allow uniform exposure to agents. Cellular senescence was induced using doxorubicin, a DNA-damaging agent. Senescence markers, such as {beta}-galactosidase ({beta}-gal) activity, SASP cytokine production and secretion, cell morphology, proliferative capacity, and barrier integrity were evaluated to validate the senescent phenotype. Results: The doxorubicin-induced senescent hiPSC-derived lung cells demonstrated the hallmark characteristics of cellular senescence, including increased {beta}-gal activity and increased production of the pro-inflammatory SASP cytokine IL-6 and increased secretion of TNF-. Senescent cells displayed enlarged morphology, decreased proliferation, and reduced wound repair capacity. Barrier integrity was impaired with decreased electrical resistance, and increased permeability, as well as expression of abnormal tight junction proteins and increased fibrosis, all consistent with the senescent lung. Conclusion: Our hiPSC-derived lung cell senescent model reproduces key aspects of human lung senescence and offer an in vitro tool for studying age-related lung disease mechanisms and therapeutic interventions. This model has potential applications in exploring the impact of environmental factors (e.g., toxins, infectious pathogens, etc.) on the senescent lung and assessing treatments that could mitigate pathologies associated with pulmonary aging including barrier impairment, inflammation and fibrosis.

The incidence of inflammatory bowel disease among the elderly has significantly risen in recent years, posing a growing socioeconomic burden to aging societies. Moreover, non-gastrointestinal diseases, also prevalent in this demographic, have been linked to intestinal barrier dysfunction, thus highlighting the importance of investigating aged-mediated changes within the human gut. While gastrointestinal pathology often involves an impaired gut barrier, the impact of aging on the human gastrointestinal barrier function remains unclear. To explore the effect of senescence, a key hallmark of aging, on gut barrier integrity, we established and evaluated an

Autophagy is a waste-disposal pathway that protects against age-related pathology. It is widely accepted that autophagy declines with age, yet the role that sex and diet-related obesity play during aging remain unknown. Here, we present the most comprehensive in vivo study of autophagic flux to date. We employed transgenic mice overexpressing tandem-florescent LC3B (RFP-GFP-LC3B) to measure autophagic flux in the blood (PBMCs), heart, and motor cortex neurons of aging mice that were fed regular chow or a high-fat diet for 6-, 12- or 18-months. In male mice, aging decreased autophagic flux in the heart, increased it in the blood, and had no effect in motor cortex neurons. Age-dependent changes autophagic flux were less pronounced in female mice. High-fat diet influenced autophagic flux in the blood and heart of male but not female mice. Overall, we uncovered sexual dimorphisms that underpin how autophagy changes with age across different tissues and in response to a high-fat diet.

Frontotemporal dementia (FTD) shows autosomal dominant transmission in up to a third of families, enabling the study of presymptomatic and prodromal phases. Despite self-reported well-being and normal daily cognitive functioning, brain structural changes are evident a decade or more before the expected onset of disease. This divergence between cognitive function and brain structure contrasts with the coupling of structural and functional decline after symptom onset. In healthy ageing, it has been shown that functional connectivity is a better predictor of cognitive function than volumetric structural imaging. We previously proposed that in the presymptomatic phase of genetic FTD, the maintenance of brain functional network integrity enables mutation carriers to sustain cognitive performance. However, prior work has focused on a small number of, often predefined, networks. This provides a limited and potentially biased characterisation of the substrates and moderators of brain network integration. Here, we test the hypothesis that brain-wide functional integration in FTD determines resilience to progressive pathology before symptom onset. We assess functional connectome integration in 289 presymptomatic FTD-mutation carriers using functional magnetic resonance imaging in relation to cognition and contrast with 271 family members without mutations. Because structural atrophy, functional integration and cognitive profiles are multivariate, we used canonical correlation models, supplemented by multiple linear regression models for each imaging modality. We confirmed progressive atrophy and normal cognitive function in presymptomatic carriers compared to non-carriers. Notably, functional integration was preserved in presymptomatic carriers across age, while it declined in familial non-carriers. The strongest effects were observed in cognitive control networks. The changes in functional integration in presymptomatic carriers were behaviourally relevant and independent of the severity of atrophy, suggesting a resilience mechanism in those at risk of dementia. To generate hypotheses about the genetic and neurometabolic basis of resilience, we assessed the spatial overlap between behaviourally-relevant functional integration maps and gene transcription profiles. These spatial correlations suggested resilience signatures to glial cell composition (astrocytes, microglia, oligodendrocytes), revealing cellular mechanisms inaccessible to standard neuroimaging. Our findings suggest that resilience to atrophy arises from enhanced functional integration, protecting against clinical conversion for many years in individuals at risk of dementia. This result has implications for the design of presymptomatic disease-modifying therapy trials and gives hope for therapeutic strategies aimed at enhancing resilience and ability to maintain function despite the presence of genetically determined neuropathology.

Aging is a multifaceted process influenced by intrinsic and extrinsic factors, with lipid alterations playing a critical role in brain aging and neurological disorders. This study introduces DoliClock, a lipid-based biological aging clock designed to predict the age of the prefrontal cortex using post-mortem lipidomic data. Significant age acceleration was observed in samples with autism, schizophrenia, and Down syndrome, with autism showing the most pronounced effects in aging-rate. An increase in entropy around age 40, suggests dysregulation of the mevalonate pathway and dolichol accumulation. Dolichol, a lipid integral to N-glycosylation and intracellular transport, emerged as a potential aging biomarker, with specific variants such as dolichol-19 and dolichol-20 showing unique age-related associations. These findings suggest that lipidomics can provide valuable insights into the molecular mechanisms of brain aging and neurological disorders. By linking dolichol levels and entropy changes to aging, this study highlights the potential of lipid-based biomarkers for understanding and predicting biological age, especially in conditions associated with premature aging.

Keloids are pathological scars exhibiting tumour-like aggressiveness and high recurrence rate. Here we find increased proportion of pro-inflammatory and mesenchymal fibroblast subpopulations and senescent fibroblasts, and enhanced expression of senescence-associated secretory phenotype genes using single-cell RNA sequencing analysis, as well as elevated p16 protein and more β-galactosidase-positive cells in keloids. The up-regulated p53-serine15 phosphorylation (p53-pS15) in keloids is identified by phosphospecific protein microarray and western blotting. We further demonstrate that a senolytic FOXO4-D-retro-inverso-isoform peptide (FOXO4-DRI) promotes apoptosis and decreases G0/G1 phase cells in pro-senescence models of keloid organ cultures and fibroblasts, accompanied with p53-pS15 nuclear exclusion. Our study indicates that upregulation of p53-pS15 and p16 maintains a persistent senescent microenvironment to promote cell cycle arrest and apoptosis resistance in keloid fibroblasts. FOXO4-DRI shows potential as a treatment targeting the senescence and apoptosis resistance, and holds promise as an approach to prevent the aggressiveness and relapse of keloids.

Impaired glucose uptake in the brain is an early presymptomatic manifestation of Alzheimer's disease (AD), with symptom-free periods of varying duration that likely reflect individual differences in metabolic resilience. We propose a systemic "bioenergetic capacity", the individual ability to maintain energy homeostasis under pathological conditions. Using fasting serum acylcarnitine profiles from the AD Neuroimaging Initiative as a blood-based readout for this capacity, we identified subgroups with distinct clinical and biomarker presentations of AD. Our data suggests that improving beta-oxidation efficiency can decelerate bioenergetic aging and disease progression. The estimated treatment effects of targeting the bioenergetic capacity were comparable to those of recently approved anti-amyloid therapies, particularly in individuals with specific mitochondrial genotypes linked to succinylcarnitine metabolism. Taken together, our findings provide evidence that therapeutically enhancing bioenergetic health may reduce the risk of symptomatic AD. Furthermore, monitoring the bioenergetic capacity via blood acylcarnitine measurements can be achieved using existing clinical assays.

Brain age gap (BAG) is a valuable biomarker for evaluating brain healthy status and detecting age-associated cognitive degeneration. However, the genetic architecture of BAG and the underlying mechanisms are poorly understood. Here, we estimate brain age from magnetic resonance imaging with improved accuracy using our proposed adversarial convolution network (ACN), followed by applying the ACN model to an elder cohort from UK Biobank. The genetic heritability of BAG is significantly enriched in the regulatory regions and implicated in glial cells. We prioritize a set of BAG-associated genes, and further characterize their expression patterns across brain cell types and regions. Two BAG-associated genes, RUNX2 and KLF3, are found as associated with epigenetic clock and diverse aging-related biological pathways. Finally, two BAG-associated hub transcription factors, KLF3 and SOX10, are identified as regulators of pleiotropic risk genes from diverse brain disorders. Altogether, we improve the estimation of BAG, and identify BAG-associated genes and regulatory networks that are implicated in brain disorders.

The indexed individual, from now on termed M116, was the world's oldest verified living person from January 17th 2023 until her passing on August 19th 2024, reaching the age of 117 years and 168 days (https://www.supercentenarian.com/records.html). She was a Caucasian woman born on March 4th 1907 in San Francisco, USA, from Spanish parents and settled in Spain since she was 8. Although centenarians are becoming more common in the demographics of human populations, the so-called supercentenarians (over 110 years old) are still a rarity. In Catalonia, the historic nation where M116 lived, the life-expectancy for women is 86 years, so she exceeded the average by more than 30 years (https://www.idescat.cat). In a similar manner to premature aging syndromes, such as Hutchinson-Gilford Progeria and Werner syndrome, which can provide relevant clues about the mechanisms of aging, the study of supercentenarians might also shed light on the pathways involved in lifespan. To unfold the biological properties exhibited by such a remarkable human being, we developed a comprehensive multiomics analysis of her genomic, transcriptomic, metabolomic, proteomic, microbiomic and epigenomic landscapes in different tissues, comparing the results with those observed in non-supercentenarian populations. The picture that emerges from our study shows that extremely advanced age and poor health are not intrinsically linked and that both processes can be distinguished and dissected at the molecular level.

Telomeres shorten with each cell division, acting as a chronometer of cell age. The enzyme telomerase, primarily active in stem cells, reverses telomere erosion. We have previously observed that transient transfection with human TERT mRNA extends telomeres and mitigates hallmarks of senescence in replicatively aged human cells or those affected by Hutchinson-Gilford progeroid syndrome (HGPS). However, due to its short half-life, mRNA requires frequent administration. In this study, we hypothesized that TERT circular (circ) RNA would extend the duration of telomerase expression and be more effective at reversing hallmarks of senescence in endothelial cells derived from HGPS patients. We observe that a single transfection of TERT circRNA is more effective than mRNA in the extension of telomere length, as determined by quantitative fluorescence in situ hybridization. Furthermore, TERT circRNA reduced the number of β-gal positive cells by three-fold and normalized nuclear morphology in HGPS endothelial cells (HGPS-ECs). Moreover, TERT circRNA substantially reduced senescent markers, inflammatory markers, and DNA damage markers, including Progerin, p16, p21, IL-1B, IL-6, IL-8, MCP1, and γH2AX. Additionally, it restored NO production, enhanced cell proliferation, promoted angiogenesis, improved LDL uptake, reduced mitochondrial ROS, and normalized mitochondrial membrane potential more effectively. Our data suggest that TERT circRNA is superior to linear TERT mRNA in reversing processes involved in senescence.

Work in many systems has shown large-scale changes in gene expression during aging. However, many studies employ just two, arbitrarily-chosen timepoints at which to measure expression, and can only observe an increase or a decrease in expression between "young" and "old" animals, failing to capture any dynamic, non-linear changes that occur throughout the aging process. We used RNA sequencing to measure expression in male head tissue at 15 timepoints through the lifespan of an inbred Drosophila melanogaster strain. We detected >6,000 significant, age-related genes, nearly all of which have been seen in previous Drosophila aging expression studies, and which include several known to harbor lifespan-altering mutations. We grouped our gene set into 28 clusters via their temporal expression change, observing a diversity of trajectories; some clusters show a linear change over time, while others show more complex, non-linear patterns. Notably, re-analysis of our dataset comparing the earliest and latest timepoints - mimicking a two-timepoint design - revealed fewer differentially-expressed genes (around 4,500). Additionally, those genes exhibiting complex expression trajectories in our multi-timepoint analysis were most impacted in this re-analysis; their identification, and the inferred change in gene expression with age, was often dependent on the timepoints chosen. Informed by our trajectory-based clusters, we executed a series of gene enrichment analyses, identifying enriched functions/pathways in all clusters, including the commonly seen increase in stress- and immune-related gene expression with age. Finally, we developed a pair of accessible Shiny apps to enable exploration of our differential expression and gene enrichment results.

Intensive efforts have been made to identify features that could serve as biomarkers of aging. Yet, drug-based interventions aimed at lessening the detrimental effects of getting older are lacking. This is largely attributable to tissue-specificity, sex-related differences, and to the difficulty of identifying actionable targets, which continues to pose a significant challenge. Here, we implement a bioinformatics approach revealing that aging-associated increase of the transmembrane Ectodysplasin-A2-Receptor is a prominent tissue-independent alteration occurring in humans and other species, and is particularly pronounced in models of accelerated aging. We show that strengthening of the Ectodysplasin-A2-Receptor signalling axis in myogenic precursors and differentiated myotubes suffices to trigger potent parainflammatory responses, mirroring aspects of aging-driven sarcopenia. Intriguingly, obesity, insulin-resistance, and aging-related comorbidities, such as type-2-diabetes, result in heightened levels of the Ectodysplasin-A2 ligand. Our findings suggest that targeting the Ectodysplasin-A2 surface receptor represents a promising pharmacological strategy to mitigate the development of aging-associated phenotypes.

Association of both intrinsic and extrinsic risk factors leading to accelerated skin ageing is reflected in excessive ROS production and ir/reversible mitochondrial injury and burnout, as abundantly demonstrated by accumulating research data. Due to the critical role of mitochondrial stress in the pathophysiology of skin ageing and disorders, maintained (primary care) and restored (secondary care) mitochondrial health, rejuvenation and homoeostasis are considered the most effective holistic approach to advance dermatological treatments based on systemic health-supportive and stimulating measures. Per evidence, an effective skin anti-ageing protection, wound healing and scarring quality - all strongly depend on the sustainable mitochondrial functionality and well-balanced homoeostasis. The latter can be objectively measured and, if necessary, restored in a systemic manner by pre- and rehabilitation algorithms tailored to individualised patient profiles. The entire spectrum of corresponding innovations in the area includes natural and systemic skin rejuvenation, aesthetic and reconstructive medicine, sustainable skin protection and targeted treatments of skin disorders. Contextually, mitochondria-centric dermatology is instrumental for advanced 3PM-guided approach which makes a good use of predictive multi-level diagnostics and targeted protection of skin against both - the health-to-disease transition and progression of relevant disorders. Cost-effective targeted protection and new treatment avenues focused on sustainable mitochondrial health and physiologic homoeostasis are proposed in the article including in-depth analysis of patient cases and exemplified 3PM-guided care with detailed mechanisms and corresponding expert recommendations presented.