Exosomal microRNA-618 derived from mesenchymal stem cells attenuate the progression of hepatic fibrosis by targeting Smad4

Hepatic fibrosis (HF) is a pathological phenomenon that occurs during the process of long-term damage and repair in the liver. This condition will lead to the development of cirrhosis and even liver cancer if untreated. Previous evidence has shown that exosomes derived from mesenchymal stem cells (MSCs), carrying microRNAs (miRs), can affect the pathogenesis of HF. Therefore, the present study aimed to identify novel exosomal miRs derived from MSCs that play a critical role in the progression of HF. Next, the expression data of differentially expressed miRs (DEMs) of patients with liver cirrhosis and healthy controls were obtained from the Gene Expression Omnibus dataset. DEMs were analyzed using Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Moreover, to further confirm the function of exosomal miR-618 derived from MSCs on the pathogenesis of HF in vivo, a mouse model of HF was established. The results of the present study suggested that a close associated existed between DEMs and HF. Based on the results of the bioinformatics analysis, miR-618 was one of the main downregulated miRs involved in cirrhosis. In addition, miR-618 could be transferred from MSCs to LX-2 cells via exosomes; exosomal miR-618 derived from MSCs inhibited the viability and migration of LX-2 cells that were treated with TGF-β. Furthermore, exosomal miR-618 derived from MSCs attenuated the progression of HF via targeting Smad4. These findings indicated that treatment of exosomal miR-618 derived from MSCs might serve as a new strategy for HF.