Transcriptomics Reveals Mesenchymal Stem Cell-Derived Exosomes Activate Hepatocyte Longevity-Regulating Pathway in Acute-On-Chronic Liver Failure

Background: Acute-on-chronic liver failure (ACLF), a rapidly progressive condition with high short-term mortality in patients with chronic liver disease, has shown therapeutic responsiveness to mesenchymal stem cell-derived exosomes (MSC-exos) in preclinical studies, where exosome administration significantly attenuates hepatic injury. To comprehensively delineate the mechanistic basis of this therapeutic effect, we conducted integrated miRNA and mRNA sequencing analyses on liver tissues obtained from exosome-treated ACLF murine models. Methods: Mice subjected to a CCl4-based acute-on-chronic liver injury regimen received saline or an MSC-derived extracellular vesicle (EV) preparation intravenously through the tail vein. Liver miRNA and mRNA profiles were examined by differential expression, GSEA, functional enrichment, exploratory LASSO feature selection and integrative network analysis. Expression measurements were complemented by senescence-associated transcript assays, a Cat 3′UTR reporter assay and CCK-8 assessment in cell models. Results: Exosome treatment significantly activated longevity-regulating pathways, mitophagy, and glutathione metabolism in ACLF mice, concurrent with characteristic remodeling of hepatic immune infiltration involving follicular helper T cells, activated NK cells, and macrophage subpopulations. Hepatic injury severity demonstrated positive correlations with mmu-let-7j and Mmp27, and negative associations with mmu-let-7f-2-3p and Tmem8b. The reconstructed miRNA-mRNA network converged on FoxO signaling-mediated regulation of oxidative stress, cellular senescence and autophagy, with FoxO/Catalase (Cat) identified as core regulators. Experimental studies confirmed that MSC-derived exosomes downregulated miR-7b-5p in hepatocytes and enhanced Cat expression, with attenuation of cellular senescence. Conclusions: Integrative transcriptomic analysis revealed that MSC-exos activate the FoxO/Cat axis through miRNA-mRNA interactome remodeling, thereby orchestrating coordinated antioxidant, pro-autophagic, and anti-senescence effects alongside immune microenvironment reprogramming in liver failure. These findings establish a pivotal theoretical framework for developing exosome-based therapeutic strategies targeting hepatic disorders.