SVIP Suppresses CCl₄-Induced Liver Fibrosis By Inducing Autophagy

Objective:Liver fibrosis is a common pathological state,which is usually associated with chronic liver diseases caused by infection,drugs,metabolic disorders,or autoimmune imbalances.Liver fibrosis could be reversed by some antifibrosis therapies.If sustained liver fibrosis is not controlled,irreversible cirrhosis,even hepatocellular carcinoma and liver failure can be induced.Therefore,how to inhibit the development of liver fibrosis is of great significance in clinical treatment research.However there is no effective clinical therapy to suppress the pathological progression of liver fibrosis.Autophagy,the physiology process of providing energy through organelles broken and proteins degraded in eukaryotic cell,has a closely relationship with many diseases and even cancers.It was found in many researches that autophagy inhibits fibrosis by degrading collagen.SVIP,a novel small p97/VCP interacting protein,is highly expressed in central nervous system and also has been discovered in the primary culture hepatocytes of rats.SVIP can activate autophagy and especially related to starvation-induced autophagy.This study is to investigate the expression of SVIP and the level of autophagy in the process of liver fibrosis,and to discover the relationship between SVIP and hepatic autophagy during the process of hepatic fibrosis.In order to find a new target for inhibiting the development of liver fibrosis and reversing liver fibrosis,we observed the effect of SVIP on autophagy and inhibiting hepatic fibrosis in rat model of liver fibrosis.We try to explore a new way to restrain the irreversible stage of liver fibrosis.Methods:1.Detect the influence of SVIP on autophagy in Hep G2 cells by western blot and RT-PCR.2.Detect autophagy in Hep G2 cells treated with starvation by western blot and RT-PCR.3.Detect the changes of autophagy and SVIP in the process of liver fibrosis in CCl4-induced rats by western blot,RT-PCR and immunohistochemical staining.4.Investigate the alterations of autophagy and SVIP in CCl4 –induced Hep G2 cells with time by western blot and RT-PCR.5.Investigate the protection of SVIP overexpression and knockdown and starvation to Hep G2 cells by western blot and MTT.6.Investigate SVIP and autophagy in CCl4-induced rats treated with starvation by western blot,RT-PCR and immunohistochemical staining.Detect the inhibition of starvation to liver fibrosis by Masson's trichrome staining.Result:1.SVIP activates autophagy in Hep G2 cells.2.Starvation activates autophagy in Hep G2 cells and in rat liver.3.SVIP is positively related with the level of autophagy in the process of CCl4-induced liver fibrosis in rats.4.SVIP is positively related with the level of autophagy in CCl4-treated Hep G2 cells in different time5.SVIP has the protection effect on Hep G2 cells.Starvation increases the expression of SVIP to decrease the toxicity of CCl4.6.Starvation increases the expression of SVIP to alleviate CCl4-induced liver fibrosis in rats.Conclusion:1.The expression of SVIP and autophagy increased and then decreased during the development of hepatic fibrosis,suggesting that SVIP has the dynamic changes in regulating autophagy during the development of liver fibrosis,so SVIP may become a new diagnostic target in gentle,moderate and severe hepatic fibrosis,and is beneficial to the early prevention and reversal of hepatic fibrosis.2.The increased SVIP induced by starvation up-regulated the level of autophagy in liver and protected hepatocytes,suggesting that SVIP may be a new way to inhibit hepatic fibrosis by regulating autophagy,and a feasible treatment is provided for the reversal of hepatic fibrosis.