Longevity Papers

Skeletal muscle aging is characterized by a functional decline in muscle stem cells (MuSCs), yet the key regulatory mechanisms driving this deterioration remain poorly understood. By integrating transcriptomic profiles from aged MuSCs with data from C2C12 cells exposed to spaceflight conditions (which mimic an aging-like phenotype), we identified MORF4-related gene on chromosome 15 (MRG15) as a putative epigenetic regulator involved in age-related myogenic decline. Using a MuSC-specific inducible knockout (iKO) mouse model, we found that loss of MRG15 severely compromises myogenic differentiation and muscle regeneration. Subsequent RNA sequencing of iKO MuSCs, combined with ChIP-seq analysis of histone modifications, revealed that MRG15 modulates the chromatin landscape of myogenic genes through interaction with MyoD, thereby facilitating transcriptional activation and differentiation. Our findings establish MRG15 as a critical epigenetic regulator that cooperates with MyoD to orchestrate chromatin remodeling, thereby promoting transcriptional activation of the myogenic program. Dysregulation of MRG15 may underlie impaired muscle regeneration during aging.

Characterizing cellular aging is essential for understanding age-related diseases. While tissue-level studies reveal broad age-associated changes, they often reflect compositional shifts rather than cell-level reprogramming. The cellular damage hypothesis posits that aging involves the accumulation of DNA, chromatin, and other damage across molecular layers, increasing transcriptional entropy. Existing supervised methods for detecting cellular senescence yield cell type-specific senescence scores but rely on labeled data and lack generalizability. Here, we introduce a first-principles framework for quantifying transcriptional entropy in single cells as each cell's deviation from a transcriptomic manifold, capturing breakdown of transcriptional coordination. This unsupervised approach identifies aging-affected cell types and distinguishes two cellular aging mechanisms: loss of expression precision and activation of stress-response pathways in high entropy cells. Applied to Tabula Muris Senis and SenNet Multiome datasets, transcriptional entropy correlates with chromatin-based mitotic age and highlights regenerative tissue compartments as most affected by aging.

Epigenetic aging is a hallmark of chronic diseases, arising from sustained injuries and unresolved repairs. To investigate cell-type-specific epigenetic alterations, we built a cross-species single-cell multi-omics atlas of DNA methylomes, chromatin accessibilities, and transcriptomes on healthy, injured (human) and aging (mouse) kidneys. We identified accelerated epigenetic aging dominated by tubular epithelia in diseased kidneys. The pathological state mirrors transcriptional trajectories observed in normal aging, driven by the preferential dysregulation of lineage-specific genes lacking CpG islands. Spatially, these epigenetic changes mapped to pathological niches of failed repair. Co-profiling of single-cell DNA methylation and 3D genome architecture revealed that epithelial repair states in disease undergo significant higher-order genome reorganizations, activating genes associated with renal decline. Our findings demonstrate that epithelial aging is driven by a collapse of 3D chromatin structure and local methylome integrity, which silences cell identity and promotes a non-resolving repair state.

Cardiac aging is a major driver of cardiovascular diseases and associated mortality, yet its therapeutic options are limited. While long interspersed nuclear element-1 (LINE-1) retrotransposons are known to drive cellular senescence, their role in cardiac aging is poorly defined. Here we showed that LINE-1 expression increased in the heart with age. To investigate their role in cardiac aging, we generated cardiomyocyte-specific Mov10-knockout mice, which failed to suppress LINE-1. These mice developed LINE-1 derepression, cardiac dysfunction and premature cardiac aging by 3 months of age, accompanied by cGAS-STING activation. Pharmacological inhibition of LINE-1 reverse transcription (with 3TC) or STING (with H-151) suppressed cGAS-STING activation and attenuated senescence in Mov10-knockout H9C2 cells. Notably, both inhibitors improved cardiac function and reduced cardiac inflammation and senescence phenotypes in naturally aged mice. Together, our findings establish LINE-1 as a driver of cardiac aging via cGAS-STING activation, highlighting LINE-1 and its downstream effectors as therapeutic targets for age-related cardiac dysfunction.

The intestine plays a crucial role in regulating metabolism and immunity, with functional decline occurring during injury and ageing. Stimulating the neogenesis of intestinal stem cells (ISCs) by activating the WNT/β-catenin signalling pathway represents a promising approach for intestinal tissue regeneration and injury repair. However, effective oral delivery of functional WNT signalling agonists to the gut remains challenging. Herein, we report a potent WNT/β-catenin signalling-inducing small extracellular vesicles (sEV) that can be administered orally and present remarkable therapeutic efficacy. We demonstrate that active R-spondin1 (RSPO1) protein can be loaded onto the surface of sEV via heparan sulfate proteoglycans. Notably, sEV-delivered RSPO1 (evRSPO1) effectively induces WNT/β-catenin signalling-inducing activity, enhances ISCs proliferation, and supports intestinal organoid growth in vitro. Importantly, oral administration of evRSPO1 activates the WNT/β-catenin signalling pathway in the cryptic stem cell niche, thereby accelerating tissue repair and regeneration in a radiation-induced intestinal injury model. Furthermore, evRSPO1 treatment induces ISCs proliferation and reverses the intestinal senescence phenotype in aged mice. Collectively, this study establishes evRSPO1 as a potential first-in-class, orally deliverable therapeutic that overcomes biological barriers to activate ISCs, enabling efficient intestinal tissue repair and rejuvenation.

Achilles tendinopathy represents a prototypical musculoskeletal disorder driven by a self-perpetuating "inflammaging" vicious cycle, where chronic inflammation and stem cell senescence mutually reinforce to precipitate tissue failure. Current therapeutics inadequately address the complex intercellular signaling fueling this loop. Herein, we present a reactive oxygen species (ROS)-responsive photothermal cascade nanoplatform (LT-NPs) that couples Licochalcone A delivery with mild near-infrared (NIR) hyperthermia (∼42 °C). Unlike conventional ablative therapies, this platform leverages mild thermal stress as a safe, generalized immunometabolic modulator. Mechanistically, we identify the mitochondrial DNA (mtDNA)-cGAS-STING axis as the pivotal "bridge" connecting mitochondrial dysfunction to immune dysregulation. The LT-NPs-NIR system dismantles this pathology via a synergistic "dual-lock" strategy: (1) mild photothermal heating induces heat shock protein 70 (HSP70) to seal mtDNA leakage; and (2) released Licochalcone A directly inhibits the downstream STING sensor. Crucially, this intervention re-engineers the dysregulated crosstalk between the immune niche and tendon stroma: by reprogramming M1 macrophages toward a reparative M2 phenotype and simultaneously rescuing tendon stem/progenitor cells (TSPCs) from senescence-associated secretory phenotype (SASP)-mediated senescence, the platform effectively uncouples the reciprocal feedback loop between inflammation and degeneration. In vivo, this orchestrated restoration of the microenvironment significantly suppresses heterotopic ossification and recovers biomechanical function. Consequently, the "mild photothermal cascade" concept establishes a versatile therapeutic paradigm, offering a scalable strategy to resolve the intricate inflammation-senescence crosstalk across a broad spectrum of age-related pathologies.

Cellular senescence is a stress-induced cellular state that contributes to tissue dysfunction, chronic inflammation, and a broad range of aging-associated pathologies. The accumulation of senescent cells (SnCs) disrupt normal tissue function, positioning them as drivers of pathological decline and therapeutic targets for aging intervention. Accordingly, multiple senescence-targeted strategies have been developed, including senolytics, senomorphics, senescence immunotherapy, and restoration-oriented interventions. These approaches aim to mitigate senescence-driven pathology by eliminating senescent cells, modulating their secretory activity, or restoring cellular function. Ongoing advancements will require precise stratification of senescent states, careful assessment of long-term safety, and the integration of optimized delivery systems for targeted therapeutic outcomes.

Elucidating the mechanisms of aging is impeded by its stochastic, multi-scale nature and cellular heterogeneity, challenges that are compounded by the overwhelming volume of biomedical literature and the complexity of genome-wide datasets. To overcome these barriers, we present PersonaAI, an interactive agentic-AI framework that acts as a digital co-scientist. By integrating literature-based reasoning with autonomous in silico validation, PersonaAI synthesizes over 560,000 aging-related publications via retrieval-augmented generation (RAG) to propose mechanistic hypotheses. These hypotheses are subsequently validated by autonomous agents utilizing single-cell RNA-seq data. Using a temporal cutoff strategy restricted to pre-2020 literature, we demonstrate that PersonaAI can generate hypotheses effectively validated by post-2021 discoveries, proving its capacity for inference beyond simple information retrieval. In application, the system identified senescent Cirbp+ hepatocytes as a liver-intrinsic aging program and uncovered a middle-aged, male-specific decline in adipose stem and progenitor cells, driven by vascular niche deterioration and disrupted VEGF-VEGFR signaling. These results establish PersonaAI as a scalable platform that augments human intuition with autonomous data-driven validation, providing a generalizable platform for accelerating discovery in aging biology.

Skin aging is characterized by a progressive decline in regenerative capacity, primarily driven by fibroblast senescence, oxidative stress, chronic inflammation, and the degradation of type I/III collagen, culminating in an extracellular matrix (ECM) imbalance. Current injectable fillers-such as hyaluronic acid, collagen, and PLLA-provide temporary structural support but fail to address the underlying cellular senescence or restore ECM homeostasis, highlighting the need for regenerative biomaterials. Silk fibroin (SF), a natural protein, self-assembles into a β-sheet-rich scaffold that structurally supports fibroblasts in depositing collagen and elastin, thereby improving the skin's ECM, accelerating wound healing, and promoting tissue regeneration. However, its role in modulating fibroblast senescence and ECM remodeling remains unclear. This study demonstrates that SF provides a suitable microenvironment for the adhesion and proliferation of fibroblasts, reducing the accumulation of SASP factors and facilitating the transition of fibroblasts from a senescent to a functional state. Furthermore, SF improves the skin microenvironment by reducing reactive oxygen species (ROS) and matrix metalloproteinase (MMP) expression through modulation of the ROS-MAPK-AP-1-MMP signal pathway, thereby delaying collagen degradation in aged skin. These findings reveal that SF uniquely rejuvenates fibroblasts and restores ECM homeostasis through a non-inflammatory mechanism, distinguishing it from conventional fillers that rely on inflammatory pathways for collagen induction. This work establishes SF as a next-generation injectable biomaterial with dual targeting of cellular senescence and ECM imbalance, offering a transformative strategy for regenerative dermatology and personalized anti-aging approaches.