Longevity Papers

Senescent cells accumulate with age and contribute to tissue dysfunction and chronic inflammation. Senolytic agents that selectively eliminate senescent cells hold therapeutic promise; however, few mechanistic classes have been established. Using Cell Painting-based morphological profiling, we identified a distinct cluster of senolytic compounds comprised of both known and novel autophagy inhibitors, including AZ191, bafilomycin A1, chloroquine, daurisoline, dauricine, MCOPPB, and its derivative MS1108. These compounds selectively eliminated senescent cells by disrupting autophagic flux. Our findings reveal senescent cell dependence on autophagy as an essential survival mechanism, define the existence of a mechanistically distinct class of senolytics acting through autophagy inhibition, and demonstrate the predictive value of Cell Painting in aging-related drug discovery. Our results provide new insights into senescent cell vulnerability and expand the therapeutic landscape for aging-related pathologies by highlighting autophagy as a targetable dependency.

Hepatocyte senescence is increasingly recognized as a pathogenic driver of metabolic dysfunction-associated steatohepatitis (MASH). Through single-nucleus transcriptomic profiling, we identified a discrete population of disease-associated hepatocytes (daHep) exhibiting enrichment for senescence markers in MASH livers. The emergence of senescent hepatocytes was associated with a marked induction of hepatic thymocyte selection associated (THEMIS) expression in both murine and human MASH. Genetic ablation of Themis, either globally or specifically in hepatocytes, resulted in significant expansion of daHep and senescent hepatocyte populations and exacerbated MASH pathology in mice. Single-nucleus transcriptomic analysis revealed a central role for THEMIS in shaping the cellular landscape of both parenchymal and nonparenchymal compartments within the MASH liver microenvironment. Conversely, adeno-associated virus-mediated overexpression of THEMIS suppressed hepatocyte senescence and attenuated diet-induced MASH. Mechanistic studies revealed that THEMIS deficiency promoted aberrant ERK phosphorylation and hepatocyte senescence. These findings establish THEMIS as a critical hepatoprotective factor that restrains hepatocyte senescence and mitigates metabolic liver disease progression.

Environmental antibiotic pollution is an underexplored contributor to gut aging and chronic intestinal diseases. We provide evidence that chronic exposure to enrofloxacin (ENR), a commonly detected veterinary antibiotic, accelerates gut aging and disease progression through a mitochondria-centered mechanism. In a population-based cross-sectional analysis, recent antibiotic use was associated with increased biological age and a higher risk of diarrhea in middle-aged and older adults, supporting a link between antibiotic exposure and impaired gut health and aging processes. Using zebrafish and intestinal epithelial cell models, we demonstrate that low-dose ENR exposure impairs intestinal function, characterized by increased permeability, reduced mucus secretion, tight junction disruption, and chronic inflammation. Multi-omics profiling revealed that ENR induced gut microbial dysbiosis, reduced metabolic diversity, and intestinal hypoxia. Mitochondrial dysfunction, particularly impaired oxidative phosphorylation, was identified as the key driver of epithelial damage. Remarkably, treatment with pyrroloquinoline quinone, a mitochondrial-targeted antioxidant, reversed ENR-induced mitochondrial injury, restored intestinal integrity, reduced inflammation, and partially normalized the microbiome. Stratified analyses in the human cohort showed that higher gut microbiota-related diet quality and antioxidant capacity mitigated antibiotic-associated aging and diarrhea risk. These findings highlight mitochondrial protection and microbiota optimization as promising therapeutic strategies.

Age-associated changes in organelle structure are often viewed as passive deterioration. Our recent work challenges this view by identifying an evolutionarily conserved, age-onset remodeling of the endoplasmic reticulum (ER) that is actively driven by ER-phagy. Across multiple cell types and organisms, the ER undergoes a reduction in volume and a shift from rough ER sheets to tubular networks. ER compositional shifts accompany these changes in morphology, with declines of the proteostasis machineries enriched within rough ER and preservation of lipid-associated enzymes tied to tubular subdomains. This remodeling occurs via autolysosomal targeting and degradation of the ER, establishing selective ER-phagy as a conserved aspect of the aging process. Notably, ER-phagy is also engaged by multiple longevity paradigms, resulting in precocious, spatial reorganization of the ER. Furthermore, ER-phagy is required for lifespan extension during mTOR impairment, indicating that ER turnover is adaptive and contributes to longevity. These findings reveal ER-phagy as a regulator of organelle architecture and age-dependent shifts in cell metabolism, thus illuminating important roles for selective autophagy in shaping organelle identity and function across the lifespan.

Senile osteoporosis (SOP) is characterized by impaired osteogenesis of bone-marrow mesenchymal stem cells (MSCs). The underlying metabolic basis remains unclear. This study aimed to identify energy-regulating pathways sustaining MSC osteogenesis during aging. Progressive activation of lipophagy was observed during MSC osteogenic differentiation, coupling lipid-droplet degradation with mitochondrial β-oxidation and ATP generation. Loss of the lipophagy receptor SPARTIN disrupted this process, leading to lipid accumulation, reduced CPT1A/CPT2 expression, suppressed oxidative phosphorylation, and impaired osteogenesis in vitro and in vivo. Conditional deletion of Spart in MSCs reproduced an osteoporosis-like phenotype in young mice. Reactivation of lipophagy using bone-tropic AAV9-LAP restored mitochondrial metabolism and bone mass in both Spart-CKO and SOP mice. Pharmacological activation with digoxin produced similar effects but induced cardiotoxicity. A senescent-neutrophil-membrane-coated nanoplatform (SNM@NP-DIG) enabled bone-targeted digoxin delivery, rescuing bone mass while minimizing cardiac injury. Overall, SPARTIN-mediated lipophagy is a critical metabolic regulator of MSC osteogenesis and represents a promising therapeutic target for senile osteoporosis.

Recent studies report that epithelial differentiated cells can undergo a reverse process called dedifferentiation in response to stem cell loss. However, the extent of this reversion and the plasticity of young versus aged-differentiated cells remain unclear. Here we show that dedifferentiated corneal epithelial cells acquire a transcriptomic state closely resembling native stem cells, sustain tissue homeostasis across lifespan and efficiently repair repeated tissue injury. Transplantation of stage-specific genetically traceable aged differentiated epithelial cells onto a denuded niche reveals reversion into a stemness-like state, restoring both quiescent and active stem cell compartments. This plasticity operates within the epithelial lineage, allowing transitions along the differentiation axis, but remains restricted across lineages, as transplanted conjunctival cells fail to regenerate the corneal stem cell pool. Mechanistically, we identify niche-derived cytokines that trigger reprogramming in vivo and enhance stemness in primary human corneal epithelial cells, revealing a conserved and therapeutically exploitable pathway for epithelial regeneration.