2480-P: Effect of Visceral Adipose Tissue Derived–EVs in Promoting NASH-Associated Hepatic Fibrosis

Introduction and Objective: Visceral adipose tissue (VAT) is a metabolically active endocrine organ that contributes to the development and severity of non-alcoholic fatty liver disease (NAFLD). Increasing evidence suggests that VAT-derived factors play a critical role in driving non-alcoholic steatohepatitis (NASH)-associated liver fibrosis. However, the potential contribution of extracellular vesicles derived from VAT (VAT-EVs) under NASH conditions to liver fibrogenesis has not been fully elucidated. Methods: VAT-EVs isolated from HFHC diet-induced NASH mice were used to investigate their effects on liver fibrosis in vivo and in vitro. IVIS and EVs uptake assays were performed to assess the internalization of VAT-EVs by hepatic stellate cells. MicroRNA sequencing was conducted to identify differentially expressed miRNAs in VAT-EVs. Transcriptomic analysis and luciferase reporter assays were used to determine downstream target genes and pathways, followed by adenovirus-mediated rescue experiments for mechanistic validation. Results: VAT-EVs could be efficiently internalized by hepatic stellate cells. VAT-EVs derived from NASH mice markedly promoted liver fibrosis in vivo and upregulated fibrogenic gene expression in stellate cells in vitro. MicroRNA sequencing combined with integrative analysis identified exosomal miR-501-3p as a key mediator of liver fibrogenesis. Notably, inhibition of miR-501-3p in VAT-EVs significantly attenuated hepatic fibrosis both in vivo and in vitro. Mechanistically, TGFBR3 was identified as a direct target of miR-501-3p, and restoration of TGFBR3 expression substantially abrogated the pro-fibrotic effects induced by miR-501-3p. Conclusion: NASH mice-derived VAT-EVs promoted liver fibrosis by miR-501-3p/TGFBR3/Smad axis. Disclosure Y. Wang: None. X. Xiao: None. Funding National Natural Science Foundation of China(82070873)