The Effect And Mechanism Of Lipopolysaccharide On Hepatic Progenitor Cells Involved In Liver Fibrosis

Objective Liver fibrosis is a common pathological process of liver disease in the repair process,as an important stage in liver disease,the further development can lead to cirrhosis or even hepatocellular carcinoma(HCC),which shows that there is great significance for further study of liver fibrosis.Hepatic progenitor cells(HPCs),as stem cells,play a significant role in liver disease.HPCs can differentiate into hepatocytes or bile duct epithelial cells to repair hepatic damage.However,some researches suggested that the HPCs can also be the initial cells of HCC.Different microenvironment directly determines the different roles of HPCs in liver fibrosis.Lipopolysaccharide(LPS),also known as endotoxin,is an important composition in tumor microenvironment,which can promote the occurrence and development of liver fibrosis.HPCs can also promote liver fibrosis under certain conditions.In addition,the biological characteristics of HPCs are easily affected by the microenvironment.At present,the specific role of HPCs in liver fibrosis and the effect of LPS on differentiation of HPCs are not clear.Therefore,in this study,we will study the effect of HPCs on liver fibrosis and the role of LPS in the process,and further explore its mechanism.Methods1?The rat liver injury model was established by CCl4.Then,WB-F344 cells were transplanted to the rat with liver injury.The changes of liver fibrosis were observed by H&E staining,immunohistochemistry,Sirius red and Masson staining.2?The level of LPS in rat portal vein was detected by ELISA.The effect of WB-F344 cells on liver fibrosis was observed after removal of LPS in the intestine of rats by antibiotics.3?The morphological changes of WB-F344 cells were observed after stimulated with different concentrations of LPS in vitro.The effect of LPS on the differentiation of WB-F344 cells was detected by RT-PCR and Western blot.4 ? To study the possible mechanism of LPS on the differentiation of HPCs,the activation of the relevant signaling pathway was detected by Western blot in vitro.The effects of LPS on the differentiation of HPCs were observed after treated with the inhibitor of related signal pathway.Results1?In rat liver injury model with CCl4,WB-F344 cells transplantation significantly aggravated liver fibrosis.2?In rat liver injury model with CCl4,the level of LPS in portal was significantly increased.The degree of liver fibrosis was alleviated followed by reducing the level of LPS with antibiotic.Meanwhile,in rat liver injury model,WB-F344 cells with green fluorescentce were clustered in the liver lobe and had a tendency to become mesenchymal cells.3?LPS inhibited the differentiation of WB-F344 cells into hepatocytes and bile duct epithelial cells,promoted the differentiation of WB-F344 cells into myofibroblasts.4?The hedgehog signaling pathway was activated in WB-F344 cells after cultured with LPS.The effect of LPS on the differentiation of WB-F344 cells into myofibroblasts was significantly inhibited by GDC-0449,the inhibitor of Hedgehog signaling pathway.Conclusion Our results indicated that HPCs transplantation promoted liver fibrosis in rat liver injury model with CCl4,and LPS played an important role in this process.In vitro,LPS inhibited the normal differentiation of HPCs and induced the differentiation of HPCs into myofibroblasts.LPS promoted the differentiation of HPCs into myofibroblasts through activating the hedgehog signaling pathway,which aggravated liver fibrosis in rats.