Effect of Overexpression of Heme Oxygenase-1 in Graft Liver on Level of Serum TNF-α and Liver Injury Early after Liver Transplantation

Objective To investigate the effects of overexpression of heme oxygenase-1(HO-1) in the graft liver of rat on serum TNF-α and liver structure and function after liver transplantation.Methods Ninety Wistar rats were randomized into 3 groups: Saline pretreatment group(group S1,n=30),Cobalt protoporphyrin IX chloride pretreatment group(group S2,n=30) and zinc protoporphyrin IX pretreatment group(group S3,n=30).The at 24 rats were divided into donors and recipients in each experiment group and for orthotopic liver transplantation 24h after donor pretreatment,the other 6 rats were simply pretreated.At 24h after donor pretreatment and 1h,3h after portal vein reperfusion,blood samples were obtained to determine the levels of serum ALT and AST.The level of serum TNF-α was detected by radioimmunity.Simultaneously liver tissues were taken,the changes of liver tissues were observed by HE staining.The expression of HO-1 protein was detected by immunohistochemistry.Results ①There was no difference of the lever of serum ALT,AST,TNF-α for each experiment group after 24h pretreatment(P0.05).At each time point after portal vein reperfusion,the levels of ALT,AST,TNF-α in group S2 was significantly lower than that in group S1 and S3(P0.05),it in group S1 was significantly higher than that in group S3(P0.05);②Expression of heme oxygenase-1 protein was slight in group S3 and S1 after 24h pretreatment,and there was no difference between two groups.In group S2 it had increased after 24h pretreatment and was significantly higher than that in group S1 and S3(P0.05).At each time point after portal vein reperfusion,it in group S2 was significantly higher than that in group S1 and S3(P0.05),it in group S1 was significantly higher than that in group S3(P0.05);③Degree of graft liver injury at 3h after portal vein reperfusion in group S2 was lighter than that in group S1 and S3,and it in group S1 was lighter than that in group S2.Conclusion The overexpression of HO-1 protein in graft liver can decrease the releasing of serum TNF-α,improve the transplantated liver function and alleviate its injury.