ABSTRACT
Objective To investigate the anti-apoptosis effects of heme oxygenase-1 (HO-1) in a mouse model of liver ischemia-reperfusion ( IR ) injury and to analyze the possible mechanisms . Methods A cell model of hypoxia/reoxygenation injury was established after transfecting mouse liver AML12 cells with HO-1 small interfering RNA ( siRNA) . Real-time PCR and Western blot assay were performed to detect the changes of HO-1, B-cell lymphoma 2 (Bcl2) and caspase-3 at the cellular level. The mouse models of liver ischemia-reperfusion injury were established with/without pretreatments with cobalt proporphyrin (CoPP), CoPP+znic proporphyrin ( ZnPP) and/or ZnPP. The levels of aspartate transaminase ( AST) and alanine transaminase ( ALT) in serum samples were measured. Immunohistochemistry was used to analyze the chan-ges of caspase-3. Western blot assay was used to detect the expression of HO-1 and Bcl2 at protein level. The pathological changes of liver tissues were observed under light microscope. The apoptosis of hepatocytes was observed by using Tunel assay. Results Decreased expression of HO-1 and Bcl2 and increased expres-sion of caspase-3 were observed in the model of hypoxia/reoxygenation injury by pre-transfecting the AML12 cells with HO-1 siRNA. Compared with the IR injury group, the CoPP pretreatment group showed lower lev-els of AST and ALT (P<0. 05) and alleviated pathological damages in liver tissues. Moreover, the expres-sion of caspase-3 was inhibited, but the expression of HO-1 and Bcl2 were enhanced. Less apoptotic cells was detected by the Tunel assay (P<0. 05). However, these protective effects could be suppressed by adding ZnPP. Conclusion HO-1 has anti-apoptotic effects in the in vitro model of hypoxia/reoxygenation. CoPP can upregulate the expression of HO-1 and play the role of anti-apoptosis in a mouse model of liver is-chemia-reperfusion injury.