Serum-derived miR-574-5p-containing exosomes contribute to liver fibrosis by activating hepatic stellate cells.

AIM: To investigate the association of serum exosomes miR-574-5p with liver fibrosis, and explore the effect and mechanism of serum exosomes on HSC activation. MATERIALS AND METHODS: Using serum samples collected from healthy adults and patients with liver cirrhosis, we extracted human serum exosomes via ultra-high-speed centrifugation, and co-cultured them with hepatic stellate cells (HSCs) line LX2. LX-2-mediated intake of human serum exosomes was examined by confocal microscopy. To induce liver fibrosis, we administered 20% CCl4 to mice intraperitoneally and adopted an exoEasy MIDI kit to extract serum exosomes.Liver fibrosis-related molecules were determined via qRT-PCR, Western blot, Masson staining, and Immunohistochemical staining. RESULTS: Significantly high miR-574-5p levels were expressed in serum exosomes and were positively correlated with the expression of miR-574-5p, collagen deposition, and α-SMA expression in liver tissues of mice during liver fibrosis. Compared to healthy subjects, serum exosomes from cirrhosis patients were associated with higher expression of miR-574-5p. MiR-574-5p mimic promoted the expression of α-SMA and COL1A1 mRNA and protein in LX-2, whereas miR-574-5p inhibitor exerted no effect. CONCLUSION: This article demonstrates that miR-574-5p expression in serum exosomes is positively correlated with collagen deposition and HSC activation in liver tissues during liver fibrosis.Serum exosomes potentially activate HSC through the transfer of miR-574-5p to HSC during liver fibrosis.