Longevity Papers

The transcription factor CCAAT/enhancer binding protein alpha (C/EBP) regulates cell differentiation, proliferation, and function in various tissues, including the liver, adipose tissue, skin, lung, and hematopoietic system. Studies in rats, mice, humans, and chickens have shown that CEBPA mRNA undergoes alternative translation initiation, producing three C/EBP protein isoforms. Two of these isoforms act as full-length transcription factors with N-terminal transactivation domains and a C-terminal dimerization and DNA-binding domains. The third isoform is an N-terminally truncated variant, translated from a downstream AUG codon. It competes with full-length isoforms for DNA binding, thereby antagonizing their activity. Expression of the truncated C/EBP isoform depends on the initial translation of a short upstream open reading frame (uORF) in CEBPA mRNA and subsequent re-initiation at a downstream AUG codon, a process stimulated by mTORC1 signaling. We investigated whether the ortholog of the CEBPA gene in the evolutionarily distant, short-lived African turquoise killifish (Nothobranchius furzeri) is regulated by similar mechanisms. Our findings reveal that the uORF-mediated regulation of C/EBP isoform expression is conserved in killifish. Disruption of the uORF selectively eliminates the truncated isoform, leading to unrestrained activity of the full-length C/EBP isoforms. This genetic modification significantly extended both the median and maximal lifespan and improved the healthspan of male N. furzeri. These results highlight a conserved mechanism of CEBPA gene regulation across species and its potential role in modulating the lifespan and aging phenotypes.

Pulmonary Fibrosis (PF) is a life-threatening illness that is characterized by progressive scarring in the lung interstitium. There is an urgent need for new PF therapies because current treatments only slow down the progression of fibrosis and the median life expectancy post-diagnosis is only 4 to 6 years. Since PF patients frequently exhibit telomere attrition, overexpressing telomerase, the enzyme responsible for synthesizing telomeres represents a compelling therapeutic option. In this study, we in vitro transcribed human telomerase reverse transcriptase (hTERT) mRNA using modified nucleosides (modRNA). ModRNA hTERT treatment led to transient activation of telomerase activity in a dose-dependent manner in MRC-5 cells and, importantly, in primary human alveolar type II pneumocytes (ATII cells). Consequently, the proliferative capacity was increased, concomitant with reduced DNA damage and elongated telomere length. Notably, induction of cellular immune response was only detectable at the highest modRNA concentration, and returned to normal levels within 48 hours. Next, we demonstrated that circularized, exonuclease-resistant modRNA hTERT extended the transient expression profile which may be clinically advantageous. Finally, we provided therapeutic proof of concept in organotypic 3D ex vivo human precision-cut lung slices derived from end-stage PF patients. Intriguingly, a single modRNA hTERT treatment inhibited senescence as indicated by significantly lower levels of senescence-associated {beta}-galactosidase, and pro-inflammatory IL6 and IL8. Concurrently, the key fibrosis mediators TGF{beta} and COL1A1 were markedly reduced. In conclusion, the data presented herein provide initial evidence for the potential of RNA-based hTERT therapy for treating human lung fibrosis.

The pace of aging varies between individuals and is marked by changes in DNA methylation (DNAm) including an increase in randomness or entropy. Here, we computed epigenetic scores of aging and entropy using DNAm datasets from the Women's Health Initiative (WHI). We investigated how different epigenetic aging metrics relate to demographic and health variables, and mortality risk. Income and education, two proxies of socioeconomics (SE), had consistent associations with epigenetic aging and entropy. Notably, stochastic increases in DNAm at sites targeted by the polycomb proteins were significantly related to both aging and SE. While higher income was associated with reduced age-related DNAm changes in White women, the protective effect of income was diminished in Black and Hispanic women, and on average, Black and Hispanic women had relatively more aged epigenomes. Faster pace of aging, as estimated by the DunedinPACE, predicted higher mortality risk, while the maintenance of methylation at enhancer regions was associated with improved survival. Our findings demonstrate close ties between social and economic factors and aspects of epigenetic aging, suggesting potential biological mechanisms through which societal disparities may contribute to differences in health outcomes and lifespan across demographic groups.

Ageing is a degenerative process characterised by a decline in physiological functioning of the organism. One of the core regulators of cellular ageing are telomeres, repetitive DNA sequences of TTAGGG that cap the ends of chromosomes and are maintained by the ribonucleoprotein complex, telomerase. Age-dependent progressive loss of the telomere ends eventually induces cell cycle arrest for the induction of either replicative senescence or apoptosis. It was previously established that overexpression of the 37 kDa/ 67 kDa laminin receptor (LRP/LR) increased telomerase activity and telomere length while concomitantly reducing senescence markers in aged normal cells in vitro. Therefore, it was hypothesized that elevating LRP/LR in vivo may increase telomerase activity and hinder the ageing process on an organism scale. To this end, aged C57BL/6J mice were treated/transfected to induce an overexpression of LRP::FLAG. Various physiological tests and histological analyses were performed to assess overall organism fitness as well as to discern the treatments' ability at reducing tissue degeneration and atrophy. It was found that mice overexpressing LRP::FLAG displayed improved physiological characteristics and markedly less tissue degeneration and atrophy when compared to control and non-treated mice. Alongside these improvements, certain organs displayed increased telomerase activity with a corresponding elongation in average telomere length. In addition the overexpression of LRP::FLAG significantly improved various proliferative and anti-ageing associated proteins while causing a concomitant decrease in senescence associated proteins. These findings are therefore indicative of a novel function of LRP/LR delaying the onset of senescence, while also promoting healthier ageing through elevating TERT and telomerase activity.

Therapy-induced senescence (TIS) alters calcium (Ca²⁺) flux and Mitochondria-ER Contact Sites (MERCS), revealing critical vulnerabilities in senescent cells. In this study, TIS was induced using Doxorubicin and Etoposide, resulting in an increased MERCS contact surface but a significant reduction in ER-mitochondria Ca²⁺ flux. Mechanistically, TIS cells exhibit decreased expression of IP3R isoforms and reduced interaction between type 1 IP3R and VDAC1, impairing Ca²⁺ transfer. This flux is crucial for maintaining the viability of senescent cells, highlighting its potential as a therapeutic target. Inhibition of ER-mitochondria Ca²⁺ flux demonstrates senolytic effects both in vitro and in vivo, offering a novel strategy for targeting senescent cells.

Age-related hearing loss is characterized by senescent inner ear hair cells (HCs) and reduced autophagy. Despite the improved understanding of these processes, detailed molecular mechanisms underlying cochlear HC senescence remain unclear. Transcription Factor EB (TFEB), a key regulator of genes associated with autophagy and lysosomes, crucially affects aging-related illnesses. However, intricate regulatory networks that influence TFEB activity remain to be thoroughly elucidated. The findings revealed that RONIN (THAP11), through its interaction with host cell factor C1 (HCF1/HCFC1), modulated the transcriptional activity of Tfeb, thus contributing to the mitigation (D-galatactose [D-gal]) senescent HC loss. Specifically, RONIN overexpression improved autophagy levels and lysosomal activity and attenuated changes associated with the senescence of HCs triggered by D-gal. These findings highlight the possibility of using RONIN as a viable therapeutic target to ameliorate presbycusis by enhancing the TFEB function.

Oxidative stress plays a key role in aging and related diseases, including neurodegeneration, cancer, and organ failure. Copper (Cu), a redox-active metal ion, generates reactive oxygen species (ROS), and its dysregulation contributes to aging. Here, we develop activity-based imaging probes for the sensitive detection of Cu(I) and show that labile hepatic Cu activity increases with age, paralleling a decline in ALDH1A1 activity, a protective hepatic enzyme. We also observe an age-related decrease in hepatic glutathione (GSH) activity through noninvasive photoacoustic imaging. Using these probes, we perform longitudinal studies in aged mice treated with ATN-224, a Cu chelator, and demonstrate that this treatment improves Cu homeostasis and preserves ALDH1A1 activity. Our findings uncover a direct link between Cu dysregulation and aging, providing insights into its role and offering a therapeutic strategy to mitigate its effects.

S-adenosylmethionine (SAM), produced by SAM synthases, is critical for various cellular regulatory pathways and the synthesis of diverse metabolites. Studies have often equated the effects of knocking down one synthase with broader SAM-dependent outcomes such as histone methylation or phosphatidylcholine (PC) production. Humans and many other organisms express multiple SAM synthases. Evidence in Caenorhabditis elegans, which possesses four SAM synthase genes, suggest that the enzymatic source of SAM impacts its function. For instance, loss of sams-1 leads to enhanced heat shock survival and increased lifespan, whereas reducing sams-4 adversely affects heat stress survival. Here, we show that SAMS-1 contributes to a variety of intermediary metabolic pathways, whereas SAMS-4 is more important to generate SAM for methylation reactions. We demonstrate that loss of sams-1 exerts age-dependent effects on nuclear-encoded mitochondrial gene expression, mitochondrial metabolites, and may induce mitophagy. We propose a mechanistic model where reduced SAM from SAMS-1 acts through PC to impact mitochondria, thereby enhancing survival during heat stress.

Ionizing radiation causes three divergent effects in the human body: On one side, tissue death (= deterministic effects) sets on, on the other side, mutations and cancer growth (= stochastic effects) can occur. In recent years, the additional phenomenon of accelerated aging has come to light. In the following, we argue that these seemingly contradictory radiation responses namely: (i) increased cancer growth, (ii) ablation of cancer tissue or (iii) deterministic senescence, share an underlying cause from damage at the lamin A C-terminus. In other words, besides the typically described genomic radiation impact, we propose an additional destabilization pathway via oxidation at the nuclear envelope. We propose five concrete hypotheses that draw a direct mechanistic model from radiation damage and cellular oxidative stress, to micronuclei and clinical symptoms. In conjunction with lamin B compensation, we might be able to explain why deterministic or stochastic responses dominate. If our model holds true, a novel target for radiotherapeutics and radiooncology arises, and a rationale to closer connect laminopathy and radioprotection research.

Aging changes the protein activity status to affect the body's functions. However, how aging regulates protein posttranslational modifications (PTMs) to modulate the antiviral defense ability of the body remains unclear. Here, we found that aging promotes STAT1 β-hydroxybutyrylation (Kbhb) at Lys592, which inhibits the interaction between STAT1 and type-I interferon (IFN-I) receptor 2 (IFNAR2), thereby attenuating IFN-I-mediated antiviral defense activity. Additionally, we discovered that a small molecule from a plant source, hydroxy camptothecine, can effectively reduce the level of STAT1 Kbhb, thus increasing antiviral defense ability in vivo. Further studies revealed that STAT1 O-GlcNAc modifications at Thr699 block CBP-induced STAT1 Kbhb. Importantly, fructose can improve IFN-I antiviral defense activity by orchestrating STAT1 O-GlcNAc and Kbhb modifications. This study reveals the significance of the switch between STAT1 Kbhb and O-GlcNAc modifications in regulating IFN-I antiviral immunity during aging and provides potential strategies to improve the body's antiviral defense ability in elderly individuals.

Both environmental exposures and genetics are known to play important roles in shaping human aging. Here we aimed to quantify the relative contributions of environment (referred to as the exposome) and genetics to aging and premature mortality. To systematically identify environmental exposures associated with aging in the UK Biobank, we first conducted an exposome-wide analysis of all-cause mortality (n = 492,567) and then assessed the associations of these exposures with a proteomic age clock (n = 45,441), identifying 25 independent exposures associated with mortality and proteomic aging. These exposures were also associated with incident age-related multimorbidity, aging biomarkers and major disease risk factors. Compared with information on age and sex, polygenic risk scores for 22 major diseases explained less than 2 percentage points of additional mortality variation, whereas the exposome explained an additional 17 percentage points. Polygenic risk explained a greater proportion of variation (10.3-26.2%) compared with the exposome for incidence of dementias and breast, prostate and colorectal cancers, whereas the exposome explained a greater proportion of variation (5.5-49.4%) compared with polygenic risk for incidence of diseases of the lung, heart and liver. Our findings provide a comprehensive map of the contributions of environment and genetics to mortality and incidence of common age-related diseases, suggesting that the exposome shapes distinct patterns of disease and mortality risk, irrespective of polygenic disease risk.

Dysregulated proteostasis, leading to accumulation of misfolded proteins, electron-dense aggregates (lipofuscin, LF), preamyloid oligomers (PAOs), and proteotoxic stress is a hallmark of aging. We investigated how efficiently proteostatic adaptations to chronic cardiac cyclic adenosine monophosphate (cAMP)-dependent stress change with aging in mice harboring marked, cardiac-specific over-expression of adenylyl cyclase VIII (TGAC8). We assessed protein quality control (PQC) mechanisms: ubiquitin proteasome system (UPS), autophagic flux via macroautophagy, and mitophagy in left ventricles (LVs) of TGAC8 and wild type littermates (WT) at 3-4 months and at 17-21 months of age. At 3-4 months of age TGAC8 mice exhibited markers of increased autophagic flux, measured by levels of microtubule-associated protein 1 light chain 3 (LC3), p62, and their phospho-forms in TGAC8 LV; cathepsin L1 activity was also significantly increased. In addition, canonical mitophagy signaling was enhanced, as receptors PARKIN, p62S403 and p62S349 were all upregulated, confirming a more efficient proteostasis in TGAC8 at 3-4 months vs WT. In advanced age, however, the PQC mechanisms were overwhelmed by proteotoxic stress, manifested in insufficient proteasome activity and an unbalanced autophagic flux (accelerated for markers such as LC3A in the context of a slower overall flux), leading to an increase in the accumulation of protein aggregates (increased ratio of insoluble/soluble protein fractions). Although both canonical (PARKIN, p62S403 and p62S349 receptors) and non-canonical (FKBP8 receptor) mitophagy signaling were upregulated in advanced age in TGAC8, mitophagy was markedly impaired and mitochondrial dysfunction increased. Accumulation of LF bodies, of brownish-to-black pigments, and of LC3+ and p62+-inclusions of aberrant sizes, of desmin cardiac preamyloid oligomers (PAOs) and of cleaved desmin, tagged for ubiquitination, were all increased in TGAC8 compared to young TGAC8. In contrast, the rate of protein synthesis and levels of soluble aggregates were reduced in aged vs young TGAC8, a sign of normal aging. Thus, increased proteostatic mechanisms maintain cardiac health in TGAC8 in youth (3-4 months), but long-term exposure to chronic cardiac stress, imposed by sustained activation of the AC/cAMP/PKA/Ca2+ signaling axis, results in severely dysregulated proteostasis in TGAC8 vs WT mice, associated with proteostatic insufficiency and increased cardiomyopathy that leads to accelerated cardiac aging.

The structure and function of the brain and cardiovascular system change over the lifespan. In this study, we aim to establish the extent to which age-related changes in these two vital organs are linked. Utilizing normative models and data from the UK Biobank, we estimate biological ages for the brain and heart for 2,904 middle-aged and older healthy adults, including both males and females. Biological ages were based on multiple structural, morphological, and functional features derived from brain and cardiovascular imaging modalities. We find that cardiovascular aging, particularly aging of its functional capacity and physiology, is selectively associated with the aging of specific brain networks, including the salience, default mode, and somatomotor networks as well as the subcortex. Our work provides unique insight into brain-heart relationships and may facilitate an improved understanding of the increased co-occurrence of brain and heart diseases in aging.

Age-related thymic involution precedes aging of all other organs in vertebrates and initiates the process of declining T cell diversity, which leads to eventual immune dysfunction. Whether FGF21, a liver-derived pro-longevity hormone that is also produced in thymic stroma, including by adipocytes, controls the mechanism of thymic demise is incompletely understood. Here, we demonstrate that elevation of FGF21 in thymic epithelial cells (TECs) and in adipocytes protects against thymic aging, whereas conditional hepatic overexpression did not impact thymic biology in aged mice. Notably, elevation of thymic FGF21 increased naïve CD8 T cells in aged animals and extended healthspan. Mechanistically, thymic FGF21 overexpression elevated TECs and reduced fibroadipogenic cells. Ablation of β-klotho, the obligatory co-receptor for FGF21 in Foxn1

Lysosomes catabolize lipids and other biological molecules, a function essential for cellular and organismal homeostasis. Key to lipid catabolism in the lysosome is bis(monoacylglycero)phosphate (BMP), a major lipid constituent of intralysosomal vesicles and a stimulator of lipid-degrading enzymes. BMP levels are altered in a broad spectrum of human conditions, including neurodegenerative diseases. While a lysosomal BMP synthase was recently discovered, the enzymes that mediate BMP turnover has remained elusive. Here we show that the lysosomal phospholipase PLA2G15 is a physiological BMP hydrolase. We further demonstrate that BMP resistance to hydrolysis in the lysosome is conferred by the combination of its unique sn2, sn2 esterification position and stereochemistry, as neither feature alone is sufficient to provide this resistance. Purified PLA2G15 catabolizes most BMP species derived from cell and tissue lysosomes under acidic conditions. Furthermore, PLA2G15 catalytic activity against synthesized BMP stereoisomers with primary esters was comparable to its canonical substrates challenging the long-held thought that BMP unique stereochemistry is sufficient to confer resistance to acid phospholipases. Conversely, BMP with secondary esters and S,S stereoconfiguration is intrinsically stable in vitro and requires acyl migration for hydrolysis in lysosomes. Consistent with our biochemical data, PLA2G15-deficient cells and tissues accumulate multiple BMP species, a phenotype reversible by supplementing wildtype PLA2G15 but not its catalytically dead mutant. In addition, targeting PLA2G15 to increase BMP reverses the cholesterol phenotype in Niemann Pick Disease Type C (NPC1) patient fibroblasts and significantly ameliorates disease pathologies in NPC1-deficient mice leading to extended lifespan. Our findings establish the rules that govern the stability of BMP in the lysosome and identify PLA2G15 as a lysosomal BMP hydrolase and a potential target for therapeutic intervention in neurodegenerative diseases.

Ageing of the cardiovascular system is associated with frailty and various life-threatening diseases. As global populations grow older, age-related conditions increasingly determine healthspan and lifespan. The circulatory system not only supplies nutrients and oxygen to all tissues of the human body and removes by-products but also builds the largest interorgan communication network, thereby serving as a gatekeeper for healthy ageing. Therefore, elucidating organ-specific and cell-specific ageing mechanisms that compromise circulatory system functions could have the potential to prevent or ameliorate age-related cardiovascular diseases. In support of this concept, emerging evidence suggests that targeting the circulatory system might restore organ function. In this Roadmap, we delve into the organ-specific and cell-specific mechanisms that underlie ageing-related changes in the cardiovascular system. We raise unanswered questions regarding the optimal design of clinical trials, in which markers of biological ageing in humans could be assessed. We provide guidance for the development of gerotherapeutics, which will rely on the technological progress of the diagnostic toolbox to measure residual risk in elderly individuals. A major challenge in the quest to discover interventions that delay age-related conditions in humans is to identify molecular switches that can delay the onset of ageing changes. To overcome this roadblock, future clinical trials need to provide evidence that gerotherapeutics directly affect one or several hallmarks of ageing in such a manner as to delay, prevent, alleviate or treat age-associated dysfunction and diseases.

Understanding the evolving dynamics of the brain throughout life is pivotal for anticipating and evaluating individual health. While previous research has described age effects on spectral properties of neural signals, it remains unclear which ones are most indicative of age-related processes. This study addresses this gap by analyzing resting-state data obtained from magnetoencephalography (MEG) in 350 adults (18 to 88 y). We employed advanced time-series analysis at the brain region level and machine learning to predict age. While traditional spectral features achieved low to moderate accuracy, over a hundred time-series features proved superior. Notably, temporal autocorrelation (AC) emerged as the most robust predictor of age. Distinct patterns of AC within the visual and temporal cortex were most informative, offering a versatile measure of age-related signal changes for comprehensive health assessments based on brain activity.

Chemotherapy-induced cognitive impairment (CICI), commonly referred to as "chemobrain," is a frequent and debilitating side effect experienced by cancer survivors treated with paclitaxel (PTX). Preclinical models have shown that PTX promotes cerebromicrovascular endothelial cell senescence, leading to chronic blood-brain barrier (BBB) disruption and neuroinflammation. Conversely, the elimination of senescent cells through senolytic therapies has been shown to restore BBB integrity, reduce neuroinflammation, and alleviate PTX-induced cognitive impairment. In this study, we tested the hypothesis that PTX-induced endothelial senescence alters gene expression patterns associated with BBB integrity. To investigate this, we analyzed a scRNA-seq dataset from the brains of mice treated with a clinically relevant PTX regimen alongside vehicle-treated control mice. We identified capillary endothelial cells by their distinct transcriptomic profiles and matched these profiles to known transcriptomic markers of cellular senescence. Our analysis confirmed that PTX induces senescence in capillary endothelial cells and revealed significant transcriptional alterations linked to impaired BBB function. In senescent endothelial cells, gene set enrichment analysis (GSEA) highlighted downregulated pathways associated with cell junction assembly and upregulated pathways involved in extracellular matrix remodeling and inflammatory signaling, including Vitronectin (VTN) and Pleiotrophin (PTN) pathways. Additionally, cell-cell communication analysis revealed reduced Junctional Adhesion Molecule (JAM) signaling, further implicating senescence in BBB disruption. These findings highlight endothelial senescence as a driver of BBB dysfunction through transcriptional changes and altered intercellular signaling. The enrichment of VTN and PTN pathways in the senescent state indicates a shift toward vascular remodeling and inflammation, exacerbating microvascular fragility and BBB disruption. Supported by prior experimental findings, this study suggests that targeting endothelial senescence and its downstream effects could mitigate PTX-induced BBB dysfunction and associated cognitive impairments. These results advance our understanding of CICI pathogenesis and provide a foundation for developing therapeutic strategies aimed at preserving vascular integrity.

Stroke remains a leading cause of mortality and long-term disability worldwide, underscoring the urgent need to identify novel therapeutic targets to enhance brain circuitry repair and functional recovery. This study explores the concept of longevity assurance genes, which primarily function within genetic pathways responsible for repair and maintenance. These pathways encompass molecular and metabolic processes as well as organ- and system-level functions. To investigate this, we employed comparative transcriptomics to analyze gene expression patterns across three age groups with progressively decreasing brain plasticity: native postnatal day seven brains, and young and old naïve and lesioned rat male brains. Analysis revealed a highly symmetrical distribution of upregulated and downregulated genes in postnatal day 7 brains. In contrast, the gene expression profiles of post-stroke brains exhibited significant asymmetry, with a disproportionate increase in upregulated genes compared to downregulated ones in both young and old post-ischemic brains. Gene variance in juvenile brains predominantly reflected processes associated with brain plasticity (e.g., Dcx, Tubb2b, Dok4, Dpysl5) and cell proliferation (e.g., Bex4). Conversely, gene expression variance in young and aged post-stroke brains was largely linked to inflammatory pathways, driven by cytokine and chemokine signaling. Notably, several genes specifically upregulated in aged brains were identified, including Ehd4, Fut7, Lilrb4, Plek, Slfn13, Slc14a1, and Smpdl3a. Immune genes that facilitate synaptic plasticity during early postnatal brain development-through processes such as pruning and sprouting to establish new connections in response to external stimuli-also contribute to post-stroke damage, confirming the concept of antagonistic pleiotropy. Our results suggest that targeting age-related immune responses could be an effective therapeutic strategy for stroke recovery.

Aging is a significant risk factor for male fertility and can lead to severe developmental disorders in offspring. It disrupts testicular function and spermatogenesis, resulting in sperm abnormalities and DNA fragmentation. Male aging alters the genome and epigenome of germ cells due to persistent oxidative stress caused by the cumulative effects of environmental factors over a lifetime. At the molecular level, DNA damage occurs and is poorly repaired due to impaired DNA repair pathways, leading to unrepaired lesions and de novo mutations. Aging also creates distinct epigenetic landscapes that modify gene expression in germ cells, affect the DNA damage response, and generate de novo DNA and epigenetic mutations that are transmitted to the sperm and inherited by the offspring. This review discusses current knowledge on the age-associated effects on male germ cells and the genomic and epigenomic mechanisms contributing to altered male reproductive health and outcomes in progeny. We propose a male reproductive aging threshold, where cumulative exposure to risk factors leads to oxidative stress, impaired spermatogenesis, and altered reproductive outcomes. Finally, we discuss novel interventions to prevent premature testicular aging and emphasize the need for public health policies and counseling guidelines for men seeking paternity.

Exosomes are small vesicles with diameters ranging from 30 to 150 nm. They originate from cellular endocytic systems. These vesicles contain a rich payload of biomolecules, including proteins, nucleic acids, lipids, and metabolic products. Exosomes mediate intercellular communication and are key regulators of a diverse array of biological processes, such as oxidative stress and chronic inflammation. Furthermore, exosomes have been implicated in the pathogenesis of infectious diseases, autoimmune disorders, and cancer. Aging is closely associated with the onset and progression of numerous diseases and is significantly influenced by exosomes. Recent studies have consistently highlighted the important functions of exosomes in the regulation of cellular senescence. Additionally, research has explored their potential to delay aging, such as the alleviatory effects of stem cell-derived exosomes on the aging process, which offers broad potential for the development and application of exosomes as anti-aging therapeutic strategies. This review aims to comprehensively investigate the multifaceted impact of exosomes while concurrently evaluating their potential applications and underscoring their strategic significance in advancing anti-aging strategies.

The blood-brain barrier (BBB) is a specialized vascular structure that protects the brain microenvironment from toxins and pathogens in the blood. At the same time, the BBB presents a significant challenge for drug development, as it restricts the entry of most therapeutics into the brain. In this review, we first examine recent findings on the molecular and cellular architecture of the BBB, emphasizing the diverse mechanisms that facilitate the transport and exchange of molecules between the blood and the brain. We discuss current knowledge on the heterogeneity of the BBB along the arteriovenous axis and across different brain regions. Then, we explore the molecular and functional changes in the BBB that occur during normal aging, neurodegeneration, and acute brain injuries and how prolonged BBB impairment affects transport mechanisms and disease progression. Additionally, we discuss novel developments in drug delivery strategies to transport small molecules, biologicals or cellular therapeutics across the BBB. Finally, we examine therapeutic opportunities to restore the BBB and discuss future directions in the field.

Assessing impact on the hallmarks of aging has emerged as a novel method for prioritizing dual-purpose longevity therapeutic targets and developing drugs simultaneously targeting aging and disease. Cellular senescence, a central hallmark of aging, progressively induces cellular growth arrest and accelerates the production of a pro-inflammatory senescence-associated secretory phenotype (SASP). TGF-β signaling is situated at the center of multiple senescence-associated and aging-associated signaling pathways, and its inhibition may be favorable for aging-related disorders. A recently developed Traf2- and Nck-interacting kinase (TNIK) inhibitor, INS018_055, was identified as a potent, novel anti-fibrotic agent affecting multiple hallmarks of aging across fibrotic diseases. Thus, we hypothesized that TNIK is a potential senescence modulator and INS018_055 could attenuate senescent cell accumulation to treat specific age-related pathological processes. Using a fully automated robotics laboratory designed for automated, highly parallel, and iterative phenotypic and multi-omic analyses, we determined that pharmacological or siRNA-mediated TNIK inhibition decreased cellular senescence in multiple experimental senescence models. INS018_055 mechanistically demonstrated senomorphic activity through its reduction of SASP. Furthermore, transcriptomics analysis revealed that INS018_055 treatment reduced aging signatures and extracellular matrix fibronectin through TGF-β signaling. These findings reveal TNIK's previously unappreciated role in cellular senescence and INS018_055's senomorphic potential in mitigating processes well-established as driving organismal aging. Thus, TNIK inhibition as a novel senomorphic strategy may inform future therapeutic approaches for diverse aging-related diseases.

Dynamic changes in cell size are associated with development and pathological conditions, including aging. Although cell enlargement is a prominent morphological feature of cellular senescence, its functional implications are unknown; moreover, how senescent cells maintain their enlargement state is less understood. Here we show that an extensive remodeling of actin cytoskeleton is necessary for establishing senescence-associated cell enlargement and pro-inflammatory senescence-associated secretory phenotype (SASP). This remodeling is attributed to a balancing act between the SASP regulator GATA4 and the mechanosensor YAP on the expression of the Rho family of GTPase RHOU. Genetic or pharmacological interventions that reduce cell enlargement attenuate SASP with minimal effect on senescence growth arrest. Mechanistically, actin cytoskeleton remodeling couples cell enlargement to the nuclear localization of GATA4 and NF-κB via the Linker of Nucleoskeleton and Cytoskeleton (LINC) complex. RhoU protein accumulates in mouse adipose tissue under senescence-inducing conditions. Furthermore, RHOU expression correlates with SASP expression in adipose tissue during human aging. Thus, our study highlights an unexpected instructive role of cell enlargement in modulating the SASP and reveals a mechanical branch in the senescence regulatory network.

The Drosophila melanogaster (fruit fly) misexpression suppressor of Ras 4 (MESR4) gene encodes a potential transcription factor and plays critical roles in various biological processes, including embryonic development, lipid metabolism, eye-antennal development, and germline stem cell differentiation. However, whether it is involved in modulating intestinal homeostasis remains elusive. In this study, we provide compelling evidence demonstrating that MESR4 is a bona fide regulator in preventing age-onset intestinal leakage and dysbiosis in adult flies. Mechanistically, MESR4 is predominantly located at the nucleus of intestinal cells and controls the expression of bag-of-marbles (bam), thereby restricting the excessive activation of immune deficiency signaling during aging. The silencing of Relish (Rel), which encodes a key transcription factor of the immune deficiency signaling pathway, reverses the beneficial effects of MESR4 in mediating intestinal barrier function and fly lifespan. Collectively, our studies uncover an undescribed function of Drosophila MESR4 in the maintenance of intestinal homeostasis and overall organismal fitness.

As the only gateway governing nucleocytoplasmic transport, the nuclear pore complex (NPC) maintains fundamental cellular processes and deteriorates with age. However, the study of age-related roles of single NPC components remains challenging owing to the complexity of NPC composition. Here we demonstrate that the master energy sensor, AMPK, post-translationally regulates the abundance of the nucleoporin NPP-16/NUP50 in response to nutrient availability and energetic stress. In turn, NPP-16/NUP50 promotes transcriptomic activation of lipid catabolism to extend the lifespan of Caenorhabditis elegans independently of its role in nuclear transport. Rather, the intrinsically disordered region (IDR) of NPP-16/NUP50, through direct interaction with the transcriptional machinery, transactivates the promoters of catabolic genes. Remarkably, elevated NPP-16/NUP50 levels are sufficient to promote longevity and metabolic stress defenses. AMPK-NUP50 signaling is conserved to human, indicating that bridging energy sensing to metabolic adaptation is an ancient role of this signaling axis.

Progeria syndromes are very rare, incurable premature aging conditions recapitulating most aging features. Here, we report a whole genome, multiparametric CRISPR screen, identifying 43 genes that can rescue multiple cellular phenotypes associated with progeria. We implement the screen in fibroblasts from Néstor-Guillermo Progeria Syndrome male patients, carrying a homozygous A12T mutation in BAF. The hits are enriched for genes involved in protein synthesis, protein and RNA transport and osteoclast formation and are validated in a whole-organism Caenorhabditis elegans model. We further confirm that BAF A12T can disrupt protein synthesis rate and fidelity, which could contribute to premature aging in patients. This work highlights the power of multiparametric genome-wide suppressor screens to identify genes enhancing cellular resilience in premature aging and provide insights into the biology underlying progeria-associated cellular dysfunction.

As the global population continues to age, the prevalence of age-related diseases is increasing, significantly influencing social and economic development, the stability of social security systems, and progress in medical technology. Ferroptosis, a recently discovered form of programmed cell death driven by iron-dependent lipid peroxidation, has emerged as a key area of research. Studies have revealed a strong association between ferroptosis and senescence. In this article, we systematically summarize the molecular mechanisms and associated signaling pathways underlying ferroptosis, emphasizing its pivotal role in the onset and progression of age-related diseases. By providing new perspectives, we aim to advance understanding of the pathogenesis of age-related diseases and guide the development of effective intervention strategies.

Toll-like receptor 5 (TLR5) plays a critical role beyond its traditional function in innate immunity, significantly impacting metabolic regulation and liver health. Previously, we reported that TLR5 activation extends the healthspan and lifespan of aging mice. This study demonstrates that TLR5 deficiency leads to pronounced metabolic abnormalities with age, primarily affecting liver metabolic functions rather than intestinal inflammation. Comprehensive RNA sequencing analysis revealed that TLR5 deficiency induces gene expression changes in liver tissue similar to those caused by the methionine-choline deficient (MCD) diet, particularly affecting lipid metabolism and circadian rhythm-related genes. TLR5 knockout (TLR5 KO) mice displayed an increased propensity for liver fibrosis and lipid accumulation under the MCD diet, exacerbating liver pathology. Both hepatocytes and hepatic stellate cells in TLR5 KO mice were functionally impacted, leading to metabolic dysfunction and fibrosis. These findings suggest that TLR5 could be a significant target for addressing metabolic diseases that arise and worsen with aging. Furthermore, understanding the mechanisms by which TLR5 activation extends healthspan could provide valuable insights into therapeutic strategies for enhancing longevity and managing age-related metabolic disorders.