| Objective: 1. By dynamically observation hepatocyte proliferation and hepatocyte apoptosis in liver fibrosis, to investigate the relationship between hepatocyte proliferation , apoptosis and reversion of liver fibrosis. 2.to explore the mechanisms of hepatocyte apoptosis and the mechanisms of the antiapoptotic action of HGF in hepatocyte. Methods: Rats were randomly divided into three groups : a normal control group ,a model group and a HGF treated group.The two latter group rats were injected subcutaneously with ccl4 for 8 weeks to produce liver fibrosis. HGF was injected intraperitoneally the third group rats every day for the final 6 weeks.The rats were sacrificed after 5weeks and 8 weeks respectively. Murine sera were collected for the measurement of ALT ,AST,HA, Ⅳ -C.Excised liver tissues were fixed with 4% formaldehyde and embedded in paraffin for HE staining and VG staining.The immunohistochmical SABC technique and TUNEL methord were used to further study the PCNA expression and hepatocyte apoptosis.In addition ,Immunohistochemi -stry was performed to determine the protein of α -SMA and apoptosis related proteins Bcl-2 ,Bax,Cyt C,Caspase-3. Results: 1.Pathomorphometrical analysis: In model group on the 5th week, many fibrous tissues formed and extended into the hepatic lobules to separate them incompletely;a large ammount of inflammatory cells infiltrated in the intralobular and the interlobular regions.In model group on the 8th week, more fibrous tissues formed and the liver structure was disordered with some displacement of central veins. Many pseudolobules were observed. While in HGF treated group on the 8th week,the pathological changes of liver was rather milder (P<0.05), showing less fibrous tissue proliferation and inflammatory cell infiltration in the interlobular space by HE staining and VG staining. 2.Serum content analysis: Compared with normal control group, there was a higher level of ALT,AST,HA, Ⅳ-c in model group and HGF treated group(P<0.01). Compared with model group, serum ALT,AST,HA, Ⅳ-c content level were markedly dropped in HGF treated group at the end of the 8th week(P<0.05,respectively). 3. PCNA positive ratio analysis: Compared with normal control group, there was an increased expression of PCNA in model group and HGF treated group(P<0.01). Compared with model group at the end of the 5thweek, PCNA positive ratio was decreased in model group at the end of the 8th week (P<0.05). Compared with model group, HGF therapy enhanced the expression of PCNA at the end of the 8th week(P<0.05). 4. Apoptotic rate analysis : Compared with normal control group,there were more apoptosis hepatocyte in model group and HGF treated group. Compared with control group,the apoptotic rate of hepatocyte was decreased in HGF treated group at the end of the 8th week(P<0.05). 5. α -SMA expression analysis: Compared with normal control group ,α-SMA was highly detected in model group and HGF treated group(P<0.01)。Compared with model group,α-SMA positive cell were suppressed by HGF treatment at the end of the 8th week(P<0.05). 6. Apoptosis related proteins expression analysis: Compared with model group, Bcl-2 was up-regulated and Bax,Cyt C, Caspase-3 were down-regulated in HGF therapeutic group at the end of the 8th week(P<0.05). Conclusion: 1. Apoptosis of hepatocyte was increased compared with normal control group in liver fibrosis. A large number of apoptosis hepatocyte resulted in the badness of hepatocyte proliferation. Apoptosis of hepatocyte was the important promoter of liver fibrosis. 2. Apoptosis related proteins Bcl-2 ,Bax,Cyt C, Caspase-3 were involved in hepatocyte apoptosis of liver fibrosis. Mitochondria pathwaywas one of the mechanisms of hepatocyte pathologic apoptosis. 3. The mechanisms of reversion of liver fibrosis involved in the decreased apoptotic hepatocyte and induction of hepatocyte regenation. The antiapoptotic mechanisms of HGF depended on increased expression of Bcl-2,an inhibitor of apoptosis,and decreased expression of Bax,Cyt C,Caspase-3...
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