[Regulatory effects of microRNAs on hepatic stellate cell activation and liver fibrogenesis]

Hepatic fibrogenesis (HF) is the common consequence of various chronic liver diseases (CLD) induced by a variety of pathogenic factors. The mechanism of HF involves the interactions within different types of liver cells, cytokines, chemokines, cell mediators and multiple signaling pathways in a way of networks. As a result, excessive production and deposition of extracellular matrix (ECM) mainly composed of type I and type III fibril forming collagen destroys the original morphology, structure and function of the liver. The activation of hepatic stellate cells (HSCs), the major scar forming cells in liver, plays a crucial role in hepatic fibrogenesis. MicroRNAs are a group of short, single stranded, non-coding RNAs that can inhibit mRNA expression at the transcriptional and post transcriptional levels. They can be loaded and transferred as cargos by exosomes, to regulate the function of nearby and distant receptive cells. The expressions of many microRNAs such as miR-21, miR-29, miR-708, miR-101, miR-455, miR-146, miR-193 change significantly in activated HSCs, which regulate the activation, fibrogenic function, proliferation, apoptosis and autophagy of HSCs via affecting target genes expression and signaling pathway molecules. They are important substances and regulatory mechanism that mediate the initiation and progression of HF.