血红素加氧酶-1过表达延长肝脏低温保存时间的研究

Overexpression of Heme Oxygenase-1 Extends the Cold Preservation Time of Liver

目的研究血红素加氧酶-1(heme oxygenase-1,HO-1)过表达延长肝脏低温保存的时间及其机制。方法利用大鼠肝脏离体再灌注模型,用钴-原卟啉(cobalt protoporphyrin,CoPP)和锌-原卟啉(zinc protoporphyrin,ZnPP)特异地诱导和抑制HO-1,观察肝脏保存0、6、24h,灌注2h后的胆汁生成量,灌流液AST、LDH、TNF-α和IL-6的活性,肝脏MDA的含量,肝组织HO-1蛋白表达的Western印迹,细胞凋亡情况等。结果CoPP诱导了肝组织HO-1的表达,与未诱导24h保存组相比,CoPP诱导组的肝脏灌流液AST、LDH、TNF-α和IL-6的活性以及肝脏MDA含量显著降低,胆汁生成量明显增加,凋亡细胞数量减少(P<0·05),并与未诱导6h保存组接近。给予ZnPP后,这些保护作用消失。结论HO-1过表达延长了肝脏低温保存时间,原因可能与抗氧化应激、抑制炎性因子的表达和细胞凋亡有关。

Objective To study the protective effect of heme oxygenase-1 （ HO-1 ） overexpression in extending cold preservation time of liver. Method Isolated perfused rat liver model was set up and rats were given cobah-protoporphyrin （CoPP） as an HO-1 inducer and zinc protoporphyrin （ZnPP） as an HO-1 inhibitor. Livers were preserved for 0 h, 6 h, 24 h respectively and perfused for 2 h in vitro. Bile production, levels of AST, LDH, TNF-α and IL-6, tissue MDA concentration, HO-1 expression and apoptosis were determined. Results CoPP induced HO-1 overexpression. The levels of AST, LDH, TNF-α, IL-6, tissue MDA, apoptotic cells were decreased and the bile production in CoPP treatment group was increased as compared with the 24 h preservation group without CoPP treatment （ P 〈 0. 05 ）. No significant difference was found between the results of 6 h preservation group and those of CoPP treatment group. These protective effects were abolished by the administration of ZnPP. Conclusion Overexpression of HO-1 extends the cold preservation time of liver from 6 h to 24 h. The mechanisms underlying these beneficial effects include reduced oxidative injury and inflammatory response and prevention of apoptosis.