The Role Of Slit2/Robo4/Rho Signaling Pathway In Monocrotaline-induced Hepatic Sinusoidal Obstruction Syndrome In Rats And The Intervention Study Of Low Molecular Weight Heparin On Its

Objective1.To explore the function of Slit2/Robo4/Rho signaling pathway in monocrotaline-induced hepatic sinusoidal obstruction syndrome(HSOS),rat model of hepatic sinus obstruction syndrome(HSOS)was induced by Monocrotaline.2.To explore the protective effect of low molecular weight heparin(LMWH)on the rat model of hepatic sinus obstruction syn drome(HSOS)induced by MCT.Methods1.34 rats were randomly divided into control group and experimental group.Rats of experimental group were established with monocrotaline(MCT)by gastric lavage(160 mg/kg),and randomly sacrificed after model making for 1 day,2 days and 4 days.Rats of control group were sacrificed after modeling for 4 days.Serum alanine aminotransferase(ALT)and aspartate aminotransferase(AST)were measured by chemical method.Liver tissue damage was observed by HE staining and Masson staining.α-SMA protein expression in rat liver was measured by immunohistochemistry.The related indexes of Slit2/Robo4/Rho signaling pathway were measured by Western blot and RT-qPCR.2.24 rats were randomly divided into control group,MCT group and low molecular weight heparin group.The rats of MCT group were established with monocrotaline(MCT)by gastric lavage(160 mg/kg).The rats of LMWH group were treated by monocrotaline(MCT)by gastric lavage(160 mg/kg)and hypodermic injection of low molecular weight heparin(1.8 mg/kg).The rats were sacrificed on the 2nd day after modeling.The experiment was finished on the 2nd day after modeling.Serum alanine aminotransferase(ALT)and aspartate amin-otransferase(AST)were measured by chemical method Liver tissue damage was observed by HE staining and Masson staining.The liver Slit2、Robo4、RhoA、ROCK 1、ROCK2、MMP-9 protein expression were measured by Western blot.Results1.Compared with the control group,The liver index of the experimental group increased(P<0.05)serum AST of the 2-day group andhe 4-day group increased 4(P<0.01),serum ALT of the 2-day group increased(P<0.01).After a single intragastric administration of MCT(160 mg/kg),the congestion of hepatic sinues,the degeneration of hepatocyte and central venous endothelial cell injury of the 1-day group were obeserved,the congestion and dilatation of hepatic sinues of the 2-day group was obvious,hepatic pathological changes were more serious of the 4-day group and perisinusoidal fibrosis was seen in of the 4-day group.α-SMA protein expression inrat liver of all treatment groupwas significantly higher than the control group(P<0.01)The expression of Slit2 and Robo4 mRNA and proteinin each experimental group were lower than that of the control group(P<0.01)and gradually decreased with the prolonged administration time(P<0.05),while the expression of RhoA、Rac1、Cdc42、MMP-2 and MMP-9 mRNA and proteinnin each experimental group were higher than that of the control group(P<0.01)and gradually increased(P<0.05).2.Compared with the control group,the liver index of MCT group and low molecular weight heparin group increased(P<0.01),and the serum ALT、AST of MCT group increased(P<0.01).Compared with MCT group,the liver index in low molecular weight heparin group decreased(P<0.05),the serum ALT、AST inlow molecular weight heparin group deseased(P<0.01).The liver lobule structure of the control group was normal,hepatic sinus congestion and hepatocyte degeneration were not obesenved in the control group,while the liver pathology in the MCT group showed hepatic sinus congestion,hepatocyte degeneration,central vein endothelial injury and collagen deposition in hepatic sinus.The liver pathological injury in low molecular weight heparin group was alleviated compared with that in the MCT group.Compared with the control group,the expression of Slit2、Robo4 protein in the liver of MCT group decreased(P<0.01).The expression of Slit2、Robo4 protein in low molecular weight heparin group was higher than that in MCT group(P<0.05).,The protein expression of RhoA、ROCK1、ROCK2 and MMP-9 in MCT group was higher than that in control group(P<0.01),while the protein expression of RhoA、ROCK1、ROCK2 and MMP-9 in low molecular weight heparin group was lower than that in MCT group(P<0.01)Conclusions1.Rat HSOS was induced by single MCT,and rat liver injury was progressively aggravated.Slit2/Robo4/Rho Signaling Pathway,hepatic stellate cell activation and increase of MMP-2 and MMP-9 may be one of the important mechanisms of HSOS induced by MCT2.Rat Hepatic injury induced by MCT was alleviated with low molecular weight heparin intervention.which may be related to up regulating Slit2/robo4 expression,down regulating RhoA/ROCK signal trans duction and expression.