Extracellular vesicles from Yiguanjian-primed bone-marrow mesenchymal stem cells ameliorate chronic liver fibrosis via miR-7045-5p.

BACKGROUND: Liver fibrosis is a crucial pathological stage in the progression of chronic liver diseases. Yiguanjian (YGJ), a Chinese herbal formula, exhibits anti-inflammatory, anti-fibrotic, and hepatoprotective effects. Extracellular vesicles from bone-marrow mesenchymal stem cells (BMSC-EVs) have shown potential in treating various disorders, including liver fibrosis. This study investigated the regulatory effects of EVs from YGJ-preconditioned BMSCs (YGJ-EVs) on TGF-β1-stimulated hepatic stellate cells (HSCs) and their therapeutic potential in a mouse model of liver fibrosis, with a focus on identifying the causative microRNA cargo. METHODS: YGJ-EVs and control EVs were isolated from BMSC culture supernatants and characterized via western blotting, transmission electron microscopy, and nanoparticle tracking analysis. Their cellular uptake in vitro and in vivo was evaluated using DIR labeling. To identify candidate miRNAs mediating YGJ-EV bioactivity, miRNA microarray analysis was conducted. To assess the effect of YGJ-EVs on liver fibrosis, TGF-β1-activated HSC cells were treated with YGJ-EVs or control-EVs for 24 h, and then the expression of proteins related to fibrotic activation (COL1-A1 and α-SMA), lysosomal biogenesis (LAMP1, TPP1, CTSD, and CTSB) mitophagy (p62, LC3, PINK1, and Parkin), and the Akt/AMPK/TFEB pathway was assessed. To determine whether miR-7045-5p is the causative factor, HSC cells transfected with miR-7045-5p were similarly analyzed. RESULTS: miRNA microarray analysis revealed miR-7045-5p upregulation in YGJ-EVs versus control EVs. In CCl(4)-treated mice, YGJ-EV-derived miR-7045-5p ameliorated the liver fibrosis, improved the hepatic function, and suppressed the HSC activation by inhibiting the Akt/AMPK/TFEB pathway. In vitro, miR-7045-5p overexpression attenuated TGF-β1-induced HSC activation. CONCLUSION: YGJ increases miR-7045-5p abundance in BMSC-EVs. YGJ-EVs alleviate liver fibrosis by delivering the anti-fibrotic miRNA miR-7045-5p, which inhibits the Akt/AMPK/TFEB pathway, thereby promoting lysosomal biogenesis and mitophagy in HSCs.