Longevity Papers

This study investigates the association between dietary methyl donor nutrients intake and phenotypic aging. This cross-sectional study comprised 27,211 adult participants from the NHANES 2005-2018. The methyl-donor nutritional quality index (MNQI) was calculated by assessing the intake of the seven methyl donor nutrients: protein, folate, choline, riboflavin, vitamin B6, vitamin B12, and zinc. Phenotypic age acceleration (PhenoAge.Accel) was calculated using biochemical markers to assess biological aging. Weighted generalized linear regression models were utilized to assess the associations between MNQI and PhenoAge.Accel, and the impact of different demographic and health characteristics was evaluated through interaction effect tests. After adjusting for various potential confounding factors, a significant negative association was found between MNQI and PhenoAge.Accel (β = - 0.66; 95% CI - 0.91, - 0.40; P < 0.0001), indicating that an increase in MNQI is associated with a slowdown in PhenoAge.Accel. Furthermore, subgroup analysis indicated stronger negatively association between MNQI and PhenoAge.Accel in males (β = - 0.94; 95% CI - 1.36, - 0.52) with significant interactions (P

Elevated heme levels, a consequence of hemolysis, are strongly associated with increased susceptibility to bacterial infections and adverse sepsis outcomes, particularly in older populations. However, the underlying mechanisms remain poorly understood. Using a cecal ligation and puncture (CLP) model of sepsis, we demonstrate that elevated heme levels correlate with Kupffer cell loss, increased bacterial burden, and heightened mortality. Mechanistically, we identify mitochondrial damage as a key driver of heme- and bacterial-induced Kupffer cell PANoptosis, a form of cell death integrating pyroptosis, apoptosis, and necroptosis, as well as cellular senescence. Specifically, heme activates phospholipase C gamma (PLC-γ), facilitating the translocation of cleaved gasdermin D (c-GSDMD) to mitochondria, resulting in GSDMD pore formation, mitochondrial dysfunction, and the release of mitochondrial DNA (mtDNA) during bacterial infection. This mitochondrial damage amplifies PANoptosis and triggers the cGAS-STING signaling pathway, further driving immune senescence. Notably, PLC-γ inhibition significantly reduces mitochondrial damage, cell death, and senescence caused by heme and bacterial infection. Furthermore, we show that hemopexin, a heme scavenger, effectively mitigates sepsis-induced Kupffer cell death and senescence, enhances bacterial clearance, and improves survival outcomes in both young and aged mice. These findings establish mitochondrial damage as a central mediator of heme induced Kupffer cell loss and highlight PLC-γ inhibition and hemopexin administration as promising therapeutic strategies for combating sepsis associated immune dysfunction.

Sarcopenia, defined as the progressive loss of skeletal muscle mass and function associated with ageing, has devastating effects in terms of reducing the quality of life of older people. Muscle ageing is characterised by muscle atrophy and decreased capacity for muscle repair, including a reduction in the muscle stem cell pool that impedes recovery after injury. Histone deacetylase 11 (HDAC11) is the newest member of the HDAC family and it is highly expressed in skeletal muscle. Our group recently showed that genetic deficiency in HDAC11 increases skeletal muscle regeneration, mitochondrial function and globally improves muscle performance in young mice. Here, we explore for the first time the functional consequences of HDAC11 deficiency in old mice, in homeostasis and during muscle regeneration. Aged mice lacking HDAC11 show attenuated muscle atrophy and postsynaptic fragmentation of the neuromuscular junction, but no significant differences in the number or diameter of myelinated axons of peripheral nerves. Maintenance of the muscle stem cell reservoir and advanced skeletal muscle regeneration after injury are also observed. HDAC11 depletion enhances mitochondrial fatty acid oxidation and attenuates age-associated alterations in skeletal muscle fatty acid composition, reducing drastically the omega-6/omega-3 fatty acid ratio and improving significantly the omega-3 index, providing an explanation for improved muscle strength and fatigue resistance and decreased mortality. Taken together, our results point to HDAC11 as a new target for the treatment of sarcopenia. Importantly, selective HDAC11 inhibitors have recently been developed that could offer a new therapeutic approach to slow the ageing process.

Gut microbiota alteration during the aging process serves as a causative factor for aging-related cognitive decline, which is characterized by the early hallmark, hippocampal synaptic loss. However, the impact and mechanistic role of gut microbiota in hippocampal synapse loss during aging remains unclear. Here, we observed that the fecal microbiota of naturally aged mice successfully transferred cognitive impairment and hippocampal synapse loss to young recipients. Multi-omics analysis revealed that aged gut microbiota was characterized with obvious change in Bifidobacterium pseudolongum (B.p) and metabolite of tryptophan, indoleacetic acid (IAA) in the periphery and brain. These features were also reproduced in young recipients that were transplanted with aged gut microbiota. Fecal B.p abundance was reduced in patients with cognitive impairment compared to healthy subjects and showed a positive correlation with cognitive scores. Microbiota transplantation from patients who had fewer B.p abundances yielded worse cognitive behavior in mice than those with higher B.p abundances. Meanwhile, supplementation of B.p was capable of producing IAA and enhancing peripheral and brain IAA bioavailability, as well as improving cognitive behaviors and microglia-mediated synapse loss in 5 × FAD transgenic mice. IAA produced from B.p was shown to prevent microglia engulfment of synapses in an aryl hydrocarbon receptor-dependent manner. This study reveals that aged gut microbiota -induced cognitive decline and microglia-mediated synapse loss that is, at least partially, due to the deficiency in B.p and its metabolite, IAA. It provides a proof-of-concept strategy for preventing neurodegenerative diseases by modulating gut probionts and their tryptophan metabolites.

We have previously reported that when autophagy is suppressed in endothelial cells (ECs), a glycolytic defect limits shear-stress -induced ATP production to an extent that purinergic 2Y1 receptor (P2Y1R)-mediated activation of EC nitric oxide (NO) synthase (eNOS) is compromised. Subsequently we demonstrated the functional relevance of this finding in arteries from mice with genetic, pharmacological, and age-associated EC autophagy impairment. Using gain and loss of function approaches in vitro, we further revealed that p-PKCδ

Oxidative DNA damage is closely linked to the onset of various age-related diseases. A significant oxidation product, 8-oxo-7,8-dihydroguanine (8OG), has been considered an important epigenetic-like marker in regulating gene expression. Accurately quantifying the locus-specific 8OG levels is crucial for understanding its functional roles in disease induction and gene regulation. In this study, we developed a glycosylase cleavage-mediated extension stalling (GCES) method for the locus-specific detection and quantification of 8OG in genomic DNA. This method utilizes the 8OG-DNA glycosylase Pab-AGOG, which induces single-strand breaks in DNA containing 8OG. The resulting cleavage is then assessed and quantified by using quantitative real-time PCR (qPCR). We successfully applied this strategy to evaluate locus-specific 8OG in synthesized DNA and genomic DNA from HEK293T, HeLa, and HepG2 cell lines under oxidative stress or triclosan treatment. The results demonstrate that the GCES method is accurate and suitable for the site-specific quantification of 8OG in both synthesized and genomic DNA from biological samples. We observed an increased level of 8OG in genomic DNA from biological samples treated with H

This study investigates how miR-146a-5p, found in adipose tissue-derived small extracellular vesicles (sEV), influences mitochondrial autophagy and its impact on delaying skeletal muscle aging through the targeting of Fbx32. The findings highlight miR-146a-5p as crucial in skeletal muscle development and aging, influencing autophagy, apoptosis, differentiation, and proliferation, collectively impacting muscle atrophy. In C2C12 cells, miR-146a-5p mimics decreased apoptosis, autophagy, and reactive oxygen species (ROS) levels, while enhancing ATP production; conversely, miR-146a-5p inhibitors had the opposite effects. Furthermore, miR-146a-5p-enriched sEV from adipose tissue alleviated skeletal muscle atrophy in aged mice and promoted muscle fiber growth and repair by regulating mitochondrial autophagy and apoptosis. Mechanistically, miR-146a-5p modulated mitochondrial autophagy in myoblasts by targeting Fbx32 and impacting the FoxO3 signaling pathway. This led to a notable decrease in apoptosis-related gene expression, reduced ROS production, and elevated ATP levels. In conclusion, miR-146a-5p derived from WAT-sEV modulates myoblast autophagy, apoptosis, ROS, and differentiation through the Fbx32/FoxO3 signaling axis. This work presents a novel molecular target and theoretical framework for delaying skeletal muscle aging and developing therapies for skeletal muscle-related disorders.

Preserving hematopoietic stem cell (HSC) functionality is essential for maintaining healthy blood and the immune system throughout life. HSC function declines with age; however, the underlying mechanisms are not fully understood. Using an inducible mosaic mouse model to overexpress the transcription factor Bcl11a in the hematopoietic compartment, we found that an aging-related increase in Bcl11a mitigated HSC functional decline, promoted IL-1β production in the bone marrow (BM), and accelerated HSC attrition in a non-cell-autonomous manner. Aging-related inflammation in the BM enhanced Bcl11a and Fc receptor (FcR) expression in HSCs, and FcR signaling induced HSC differentiation. This was counteracted by Bcl11a through repression of

A chronic increase in mTORC1 signaling is implicated in reduced longevity, altered metabolism, and mitochondrial dysfunction. Abnormal mTORC1 signaling may also be involved in the etiology of sarcopenia. To better understand the role of mTORC1 signaling in the regulation of muscle metabolism we developed an inducible muscle specific DEPDC5 knockout model which results in constitutively active mTORC1 signaling. We hypothesized that constitutively active mTORC1 signaling in skeletal muscle would alter the metabolomic and lipidomic response to an acute bout of exercise. Wild-type (WT) and DEPDC5 muscle specific knockout (KO) mice were studied at rest and following a 1 hr bout of treadmill exercise. Acute exercise induced an increased reliance on glycolytic and PPP metabolites in the muscle of mice with hyperactive mTORC1. Lipidomic analysis showed an increase in triacylglycerols (TGs) in KO mice. While exercise had a pronounced effect on muscle metabolism, the genotype effect was larger, indicating that constitutively active mTORC1 signaling exerts a dominant influence on metabolic and lipidomic regulation. We conclude that increased mTORC1 signaling shifts muscle metabolism toward greater reliance on non-oxidative energy sources in response to exercise. Understanding the mechanisms responsible for these effects may lead to the development of strategies for restoring proper mTORC1 signaling in conditions such as aging and sarcopenia.

Telomere length regulation is essential for genome stability as short telomeres can trigger cellular senescence and apoptosis constituting an integral aspect of biological aging. Telomere biology disorders (TBDs) such as dyskeratosis congenita (DC) are rare, inherited diseases with known mutations in at least 16 different genes encoding components of the telomere maintenance complexes. The precise role of TEN1, part of the CST complex (CTC1, STN1, and TEN1), and the consequences of its loss of function in vivo are not yet known. We investigated the first viable murine model of

The LRRK2 G2019S mutation is known to have a high penetrance rate associated with Parkinson's disease (PD), prevalent across both familial and sporadic PD cases and implicated in neurodegenerative mechanisms. This mutation disrupts several key cellular processes, particularly affecting the endoplasmic reticulum and mitochondrial functions in neural stem cells (NSCs), which are crucial for protein homeostasis and energy metabolism. Although aging is a major risk factor for PD, the complex interplay between LRRK2 G2019S and aging-related cellular dysfunction in NSCs remains poorly understood. In this study, we performed a comprehensive transcriptomic analysis to characterize the temporal transcriptional changes in LRRK2 G2019S-carrying NSCs across sequential passages, resembling cellular aging. BAC DNA-mediated correction of the LRRK2 mutation significantly restored dysregulated cellular processes, including endoplasmic reticulum-associated protein processing, mitochondrial function, and vesicular trafficking pathways, thereby restoring cellular homeostasis in NSCs. Notably, aged NSCs harboring the LRRK2 G2019S mutation exhibited pronounced alterations in epithelial-mesenchymal transition or TGF-β signaling, exacerbating declines in NSC function. Our findings elucidate the molecular mechanisms underlying LRRK2 G2019S-mediated pathogenesis in aging NSCs and highlight the therapeutic potential of genetic correction strategies for PD treatment.

The self-renewal capacity of intestinal stem cells (ISCs) declines with aging, leading to a loss of homeostasis and an increased susceptibility to intestinal diseases. Despite the established significance of lipid metabolism and epigenetic regulation in ISC function, the molecular mechanisms that connect these processes to aging-related ISC dysfunction remain elusive. Here, we demonstrate that Histone 3 lysine 36 trimethylation (H3K36me3) caused by SETD2 is critical for ISC stemness. We found that H3K36me3 deficiency results in reduced ISC proliferation and differentiation, disrupts fatty acid oxidation (FAO) metabolism, and induces ISC senescence. Mechanistically, the loss of H3K36me3 triggers the activity of the SWI/SNF chromatin remodeling complex and leads to increased chromatin accessibility and enhancer activation, which alters FAO- and senescence-related gene expression. Importantly, we discover that metabolic intervention can prevent the senescence of ISC due to H3K36me3 deficiency. Our findings reveal a crucial role for H3K36me3 in maintaining the epigenetic landscape that orchestrates FAO metabolism and determines intestinal stem cell functions, emphasizing the role of FAO as a key modulator between H3K36me3 and ISC aging, suggesting that metabolic intervention may help mitigate age-related ISC dysfunction.

Autophagy is a crucial cellular process that facilitates the degradation of damaged organelles and protein aggregates, and the recycling of cellular components for the energy production and macromolecule synthesis. It plays an indispensable role in maintaining cellular homeostasis. Over recent decades, research has increasingly focused on the role of autophagy in regulating adult stem cells (SCs). Studies suggest that autophagy modulates various cellular processes and states of adult SCs, including quiescence, proliferation, self-renewal, and differentiation. The primary role of autophagy in these contexts is to sustain homeostasis, withstand stressors, and supply energy. Notably, the dysfunction of adult SCs during aging is correlated with a decline in autophagic activity, suggesting that autophagy is also involved in SC- and aging-associated disorders. Given the diverse cellular processes mediated by autophagy and the intricate mechanisms governing adult SCs, further research is essential to elucidate both universal and cell type-specific regulatory pathways of autophagy. This review discusses the role of autophagy in regulating adult SCs during quiescence, proliferation, self-renewal, and differentiation. Additionally, it summarizes the relationship between SC aging and autophagy, providing therapeutical insights into treating and ameliorating aging-associated diseases and cancers, and ultimately promoting longevity.

Bone fractures and related complications are a significant concern for older adults, particularly with the growing aging population. Therapeutic interventions that promote bone tissue regeneration are attractive for geriatric fracture repair. Extracellular adenosine plays a key role in bone homeostasis and regeneration. Herein, we examined the changes in extracellular adenosine with aging and the potential of local delivery of adenosine to promote fracture healing using aged mice. Extracellular adenosine level was found to be significantly lower in aged bone tissue compared to young mice. Concomitantly, the ecto-5'-nucleotidase CD73 expression was also lower in aged bone. Local delivery of adenosine using injectable, in situ curing microgel delivery units yielded a pro-regenerative environment and promoted fracture healing in aged mice. This study offers new insights into age-related physiological changes in adenosine levels and demonstrates the therapeutic potential of adenosine supplementation to circumvent the compromised healing of geriatric fractures.

While traditionally regarded as \"noise\", blood-oxygenation-level-dependent (BOLD) fMRI fluctuations coupled to systemic physiology--such as heart rate and respiratory changes--also hold valuable information about brain vascular properties and autonomic function. In this study, we leverage these physiological BOLD signals to characterize age-related changes in brain physiology. Using a large dataset from the Lifespan Human Connectome Project Aging study, we investigated how the spatiotemporal BOLD-fMRI signatures of autonomic physiology, specifically heart rate and respiratory variation, change with advancing age. Our findings reveal that aging is associated with globally slower respiratory fMRI responses, alongside faster cardiac fMRI responses and enhanced brain-cardiac signal coupling. Moreover, we show that the impact of age on physiological fMRI signals exhibits a notable turning point after age 60, suggesting a critical role of declining vascular health and autonomic function in aging. The potential impact of age-related changes in brain structure, tissue perfusion, and in-scan arousal states on the identified physiological fMRI patterns is also tested and discussed. Altogether, our results underscore significant age effects in the fMRI signatures of systemic physiology, emphasizing the pivotal role of altered vascular properties and autonomic function in aging. Methodologically, this study also demonstrates the utility of resting-state fMRI for extracting multi-parametric information about brain physiology, offering new biomarker opportunities that complement established functional connectivity metrics.

Insufficiency in nutrient availability, oxidative stress and autophagy failure are fundamental factors for the decline of bone mass and strength with aging. Accumulating evidence indicates that these factors affect normal autophagosomal or lysosomal activities which are the major force in clearance of aggregated or damaged proteins. Cathepsin D (CtsD), the principal lysosomal aspartate protease and a main endopeptidase, exists in the skeleton during development or homeostasis. However, the molecular and cellular mechanisms of CtsD mediated autophagosome or lysosome function in the skeletal homeostasis remain unclear. In the present study, we showed that deletion of CtsD dramatically decreased bone mass in the 3-week old mutant mice compared with their control littermates as indicated by decreased bone volume (BV), bone volume / total volume (BV/TV), bone surface (BS), trabecular number, trabecular thickness and increase trabecular separation in the microCT analysis. Histomorphometry analysis revealed that the phenotype was characterized by decreased osteoblast numbers, osteoblast surface/bone surface and mineral apposition rate, increased osteoclast numbers, osteoclast surface/bone surface and erosion surface/bone surface. At molecular level, siRNA medicated inactivation of CtsD in MC3T3E1 cells attenuated osteoblastic differentiation and downregulated LC3B expression, which was accompanied by decreased levels of P62, p-Akt and p-GSK3beta in osteoblasts. Intriguingly, inactivation of CtsD in RAW264.7 cells increased osteoclast differentiation with decreased LC3B expression but upregulated P62 level. This was accompanied by alterations in the formation of autophagosome and differential transcription profiles associated with the autophagy pathway during the differentiation of osteoblasts and osteoclasts. The results suggest that CtsD mediated autophagy pathway plays important roles in regulation of bone mass and homeostasis through distinct mode of actions in osteoblasts and osteoclasts, and CtsD may serve as a potential therapeutic target for the maintenance of bone mass.

Age-related macular degeneration (AMD) is a leading cause of blindness in the elderly, with dysfunction of the retinal pigment epithelium (RPE) central to disease pathogenesis. Using our uniquely developed MLST8 (MTOR associated protein, LST8 homolog) knock-in animal model with RPE-specific overexpression, which drives MTOR (mechanistic target of rapamycin kinase) upregulation, we demonstrate that increased MTOR complexes 1 and 2 in the RPE disrupts macroautophagy/autophagy by suppressing autophagosome formation genes and impairing MAP1LC3/LC3 processing. This leads to autophagosome accumulation and defective autolysosome formation, driving RPE dysfunction and AMD-like pathology, including subretinal debris build up and photoreceptor degeneration. Notably, MTOR inhibition with torin1 treatment or CRYBA1 overexpression rescues these defects, restoring autophagy and RPE integrity. Our findings reveal that autophagy disruption mediated by both MTORC1 and MTORC2 drives AMD-like pathology in our mouse model, establishing autophagy regulation as a promising avenue for therapeutic intervention in this vision-threatening disease.

This study investigates the effectiveness of quercetin (QUE) in preventing sarcopenia via the PI3K/AKT signaling pathway. Thirty SD rats were categorized into three groups: a young control group (Y), an old control group (O), and an old QUE-supplemented group (O + QUE). Body weight and grip strength were monitored weekly during the experiment. Soleus and gastrocnemius muscle weights, gastrocnemius tissue pathological examination, cell apoptosis, and mitochondrial damage were evaluated using HE, TUNEL staining, electron microscopy, and JC-1 staining. Biochemical assays and molecular biology techniques (qPCR and Western blot) were used to assess oxidative stress markers and the expression of sarcopenia-related genes and proteins. QUE supplementation increased muscle weight and improved grip strength in aged rats. Furthermore, QUE supplementation alleviated tissue damage, apoptosis, enhanced antioxidant capacity, and decreased damage to oxidative stress and mitochondria in the gastrocnemius of old rats. Molecular assessments revealed downregulation of muscle degradation markers (MuRF1, Atrogen-1, Bnip3) and upregulation of PI3K/AKT pathway proteins, suggesting a mechanistic pathway through which QUE mitigates sarcopenia. QUE maybe modulate the PI3K/AKT pathway to alleviate oxidative stress, mitochondrial damage, and muscle degradation due to aging, highlighting its potential as a therapeutic agent against sarcopenia.

Chaperone-mediated autophagy (CMA) is a selective autophagic pathway that targets specific proteins for lysosomal degradation, playing a crucial role in maintaining cellular homeostasis. Recent research has highlighted the involvement of CMA in aging and age-related diseases, yet its regulation remains complex. The study by Khawaja et al. provides novel insights into the sex-specific and cell-type-specific regulation of CMA during aging. This commentary discusses the key findings of this study, their implications for autophagy and aging research, and potential future directions. Understanding these regulatory mechanisms is essential for developing targeted therapies to combat age-related diseases and promote healthy aging.

Age-related proteinopathies, including Alzheimer's and Parkinson's disease, are driven by the toxic accumulation of misfolded proteins, particularly intrinsically disordered proteins (IDPs), that overwhelm cellular proteostasis. The proteasome is responsible for the clearance of these proteins, but it is unclear why it fails to do so in these diseases. Here, we report a novel strategy employing a C. elegans model with a hyperactive 20S proteasome (3{Delta}N) to achieve selective activation. This activation robustly enhances the degradation of IDPs and misfolded proteins, markedly reduces oxidative damage, and significantly improves ER-associated degradation (ERAD). Notably, aggregation-prone substrates, such as endogenous vitellogenins and human alpha-1 antitrypsin (ATZ), are efficiently cleared. Proteomic and transcriptomic reprogramming reveals systemic adaptations characterized by increased protein turnover and enhanced oxidative stress resistance, independent of superoxide dismutases. Strikingly, proteasome hyperactivation extends lifespan and enhances stress resistance independently of known proteostasis pathways including the canonical unfolded protein response mediated by xbp-1. Our findings provide substantial support for a "20S pathway" of proteostasis that alleviates protein aggregation and oxidative stress, offering a promising therapeutic strategy for neurodegenerative diseases.

This book chapter will focus on modifications to chromatin itself, how chromatin modifications are regulated, and how these modifications are deciphered by the cell to impact aging. In this chapter, we will review how chromatin modifications change with age, examine how chromatin-modifying enzymes have been shown to regulate aging and healthspan, discuss how some of these epigenetic changes are triggered and how they can regulate the lifespan of the individual and its naïve descendants, and speculate on future directions for the field.

Aging is associated with a progressive decline in circulating insulin-like growth factor- 1 (IGF- 1) levels in humans, which has been implicated in the pathogenesis of sarcopenia. IGF- 1 is an anabolic hormone that plays a dual role in maintaining skeletal muscle health, acting both directly on muscle fibers to promote growth and indirectly by supporting the vascular network that sustains muscle perfusion. However, the microvascular consequences of IGF- 1 deficiency in aging muscle remain poorly understood. To elucidate how impaired IGF- 1 input affects skeletal muscle vasculature, we examined the effects of endothelial-specific IGF- 1 receptor (IGF- 1R) deficiency using a mouse model of endothelial IGF- 1R knockdown (VE-Cadherin-CreER

NAD+ is an important cofactor involved in regulating many biochemical processes in cells. An imbalance in NAD+/NADH ratio is linked to many diseases. NAD+ is depleted in diabetes, cardiovascular and neurodegenerative diseases, and in aging, and is increased in tumor cells. NAD+ is generated in cells via the de novo, Preiss-Handler, and salvage pathways. Most of the cellular NAD+ is generated through Nampt activation, a key rate-limiting enzyme that is involved in the salvage pathway. Restoration of NAD+/NADH balance offers therapeutic advantages for improving tissue homeostasis and function. NAD+ is known to benefit and restore the body's physiological mechanisms, including DNA replication, chromatin and epigenetic modifications, and gene expression. Recent studies elucidate the role of NAD+ in cells utilizing transgenic mouse models. Translational new therapeutics are positioned to utilize the NAD+ restoration strategies for overcoming the drawbacks that exist in the pharmacological toolkit. The present review highlights the significance of Nampt-NAD+ axis as a major player in energy metabolism and provides an overview with insights into future strategies, providing pharmacological advantages to address current and future medical needs.

Purpose: The glymphatic system facilitates brain waste clearance via cerebrospinal fluid (CSF) flow, and its dysfunction has been linked to aging and neurodegeneration. However, clinically accessible methods to quantify glymphatic function in humans remain limited. This study aimed to examine the potential of dynamic 18F-FDG PET for measuring ventricular CSF clearance - as a surrogate marker of glymphatic function. Specifically, we evaluated its association with age, its test-retest reliability, and the feasibility of reduced scan durations for clinical applicability. Methods: We analyzed 72 baseline 18F-FDG PET scans from participants enrolled in a prior depression trial. Time-activity curves (TACs) were extracted from the lateral ventricles and fitted with a {gamma}-variate model to estimate influx (_in) and clearance (_out) parameters. Associations with age and clinical factors were examined using correlation and multiple linear regression. Test-retest reliability was assessed in 11 placebo-treated participants who underwent repeat scans eight weeks apart. A feasibility analysis tested whether shorter scan windows could yield comparable clearance estimates. Results: _out showed a strong negative correlation with age (r = -0.680, p < 0.001), while _in was not significantly age-related. Age remained a significant predictor of _out after adjusting for sex, ventricle size, and depression severity. A positive association between _out and depression severity was observed after covariate adjustment. Test-retest analysis yielded an intraclass correlation coefficient of 0.702 for _out, indicating moderate-to-good reproducibility. A shortened 30-minute scan window (starting 30 minutes post injection) preserved strong correlations with both _out and age, supporting the potential for abbreviated imaging protocols. Conclusion: Dynamic 18F-FDG PET provides a reliable and noninvasive method to quantify ventricular CSF clearance, revealing age-related decline indicative of glymphatic impairment. The method demonstrates reproducibility over time and retains key clearance metrics even with shortened scan durations. These findings establish a clinically feasible 18F-FDG PET-based approach for studying brain clearance and glymphatic function in aging and disease.

Myocardial infarction (MI) has high morbidity and mortality, and the macrophage senescence-associated secretory phenotype (SASP) plays a central role in M1 healing. α-Lipoic acid (ALA) alleviates MI by regulating the function of macrophages, although the relationship between ALA and macrophage senescence remains unclear. To investigate macrophage SASP in MI, we performed single-cell RNA sequencing (scRNA-seq) on the GEO GSE163465 dataset, along with qPCR and western blot analyses to assess SASP expression in macrophages subjected to hypoxia and ALA treatment. Immunofluorescence was used to detect SASP distribution. Coculture and animal experiments were performed to assess the therapeutic effects of ALA on macrophage senescence and cardiomyocyte ischemic injury. scRNA-seq revealed an age-independent senescent propensity of macrophages in MI. Increased expression of H2A.X, CCL7, IL1β, and CDKN1A, along with decreased SOD2 expression, confirmed that macrophage SASP occurred after hypoxia, with oxidative stress and energy metabolism involved in the process. ALA inhibited the degradation of SIRT1 and promoted the Nrf2 nuclear translocation, alleviating macrophage senescence and myocardial ischemic injury. Age-independent macrophage SASP occurred during MI. Macrophage SASP was induced by ROS and mitochondrial dysfunction. ALA alleviated SASP by decreasing ROS generation and autophagy flux while increasing SIRT1 levels, and Nrf2 nuclear translocation. ALA ameliorated MI injury.

Age-related cognitive impairment (ARCI) is linked to β-amyloid (Aβ) accumulation and disrupted blood-brain barrier (BBB) transport via receptors for advanced glycation end products (RAGE) and low-density lipoprotein receptor-related protein 1 (LRP1). This study examines electroacupuncture (EA) effects on cognition, hippocampal pathology, neurotransmitters, and the RAGE/LRP1 system in senescence-accelerated mouse prone 8 (SAMP8) mice. EA at Zusanli (ST36) and Baihui (GV20) improved cognitive performance, reduced hippocampal neuronal degeneration, elevated cerebrospinal fluid dopamine, norepinephrine, serotonin, and 5-hydroxyindoleacetic acid, and decreased Aβ42 levels. EA downregulated hippocampal RAGE, vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1), upregulated LRP1 and apolipoprotein E (ApoE), promoting Aβ clearance. NF-κB expression remained unchanged, suggesting alternative anti-inflammatory pathways. Thus, EA offers a promising non-pharmacological treatment for ARCI.

Clonal dominance characterizes hematopoiesis during aging and increases susceptibility to blood cancers and common nonmalignant disorders. VEXAS syndrome is a recently discovered, adult-onset, autoinflammatory disease burdened by a high mortality rate and caused by dominant hematopoietic clones bearing somatic mutations in the UBA1 gene. However, pathogenic mechanisms driving clonal dominance are unknown. Moreover, the lack of disease models hampers the development of disease-modifying therapies. In the present study, we performed immunophenotype characterization of hematopoiesis and single-cell transcriptomics in a cohort of nine male patients with VEXAS syndrome, revealing pervasive inflammation across all lineages. Hematopoietic stem and progenitor cells (HSPCs) in patients are skewed toward myelopoiesis and acquire senescence-like programs. Humanized models of VEXAS syndrome, generated by inserting the causative mutation in healthy HSPCs through base editing, recapitulated proteostatic defects, cytological alterations and senescence signatures of patients' cells, as well as hematological and inflammatory disease hallmarks. Competitive transplantations of human UBA1-mutant and wild-type HSPCs showed that, although mutant cells are more resilient to the inflammatory milieu, probably through the acquisition of the senescence-like state, wild-type ones are progressively exhausted and overwhelmed by VEXAS clones, overall impairing functional hematopoiesis and leading to bone marrow failure. Our study unveils the mechanism of clonal dominance and provides models for preclinical studies and preliminary insights that could inform therapeutic strategies.

A global obesity pandemic, coupled with an increasingly ageing population, is exacerbating the burden of cardiovascular disease. Indeed, clinical and experimental evidence underscores a potential connection between obesity and ageing in the pathogenesis of various cardiovascular disorders. This is further supported by the notion that weight reduction not only effectively reduces major cardiovascular events in elderly individuals but is also considered the gold standard for lifespan extension, in obese and non-obese model organisms. This review evaluates the intricate interplay between obesity and ageing from molecular mechanisms to whole organ function within the cardiovascular system. By comparatively analysing their characteristic features, shared molecular and cell biological signatures between obesity and ageing are unveiled, with the intent to shed light on how obesity accelerates cardiovascular ageing. This review also elaborates on how emerging metabolic interventions targeting obesity might protect from cardiovascular diseases largely through antagonizing key molecular mechanisms of the ageing process itself. In sum, this review aims to provide valuable insight into how understanding these interconnected processes could guide the development of novel and effective cardiovascular therapeutics for a growing aged population with a concerning obesity problem.

Aging is an inevitable biological process, driven in part by increased oxidative stress, which accelerates cellular damage and contributes to immune system dysfunction. Therefore, targeting oxidative stress has emerged as a potential strategy. Pyrroloquinoline quinone (PQQ), a potent antioxidant, has demonstrated significant efficacy in reducing oxidative stress and modulating immune responses, making it a promising therapeutic candidate. In this study, we investigated the effects of aging on the hematopoietic immune system (HIS) through single-cell RNA sequencing (scRNA-seq) of spleen and bone marrow cells in murine models. Our results revealed widespread age-related inflammation and oxidative stress within immune cell populations. Notably, long-term PQQ supplementation improved physiological parameters and reduced blood inflammatory factors levels in aged mice. Subsequent scRNA-seq analysis demonstrated that PQQ supplementation effectively reduced oxidative stress levels across various HIS cell types and reversed aging-related phenotypes, such as inflammatory responses and immunosenescence. Additionally, PQQ reversed aging-induced disrupted signaling and restored immune homeostasis, particularly in B cells and hematopoietic stem cells (HSCs). Importantly, we identified critical molecular targets, including ASPP1, which mediates PQQ's anti-apoptotic effects in B cells, and Yy1 and CD62L, which were upregulated by PQQ to restore HSCs self-renewal and differentiation potential. Furthermore, the machine learning program and experimental validation demonstrated the senolytic and senomorphic effects of PQQ in vivo and vitro. These findings underscore PQQ's potential not only in mitigating oxidative stress but also in restoring immune homeostasis and promoting cellular regeneration, highlighting its therapeutic potential in addressing immune aging and improving physiological function.

Reprogramming of aged donor tissue cells into induced pluripotent stem cells (A-iPSC) preserved the epigenetic memory of aged-donor tissue, defined as genomic instability and poor tissue differentiation in our previous study. The unbalanced expression of RNA exosome subunits affects the RNA degradation complex function and is associated with geriatric diseases including premature aging and cancer progression. We hypothesized that the age-dependent progressive subtle dysregulation of EXOSC2 (exosome component 2) causes the aging traits (abnormal cell cycle and poor tissue differentiation). We used embryonic stem cells as a tool to study EXOSC2 function as the aging trait epigenetic memory determined in A-iPSC because these aging traits could not be studied in senesced aged cells or immortalized cancer cells. We found that the regulatory subunit of PP2A phosphatase, PPP2R5E, is a key target of EXOSC2 and this regulation is preserved in stem cells and cancer.

Neurodegenerative diseases including Alzheimer's and Parkinson's disease are age-related disorders which severely impact quality of life and impose significant societal burdens. Cellular senescence is a critical factor in these disorders, contributing to their onset and progression by promoting permanent cell cycle arrest and reducing cellular function, affecting various types of cells in brain. Recent advancements in regenerative medicine have highlighted "R3" strategies-rejuvenation, regeneration, and replacement-as promising therapeutic approaches for neurodegeneration. This review aims to critically analyze the role of cellular senescence in neurodegenerative diseases and organizes therapeutic approaches within the R3 regenerative medicine paradigm. Specifically, we examine stem cell therapy, direct lineage reprogramming, and partial reprogramming in the context of R3, emphasizing how these interventions mitigate cellular senescence and counteracting aging-related neurodegeneration. Ultimately, this review seeks to provide insights into the complex interplay between cellular senescence and neurodegeneration while highlighting the promise of cell-based regenerative strategies to address these debilitating conditions.

The development of age-related neurodegenerative diseases is associated with the accumulation of damaged and misfolded proteins. Such proteins are eliminated from cells by proteolytic systems, mainly by 20S proteasomes, whose activity declines with age. Its stimulation has been recognized as a promising approach to delay the onset or ameliorate the symptoms of neurodegenerative disorders. Here we present peptidomimetics that are very effective in stimulating the proteasome in biochemical assays and in cell culture. They are stable in human plasma and capable of penetrating the cell membranes. The activators demonstrated the ability to enhance h20S degradation of α-synuclein and tau, whose aggregates are involved in the development of Parkinson's and Alzheimer's diseases, respectively. The peptidomimetics did not show cytotoxicity to HEK293T and primary hippocampal cells. Additionally, these compounds were highly effective in reducing the amount of phosphorylated α-synuclein aggregates in hippocampal neurons in a mouse embryonic cell model.