血红素氧合酶-1减轻大鼠移植肝缺血再灌注损伤的作用及机制

目的 探讨血红素氧合酶-1(HO-1)减轻大鼠移植肝缺血再灌注损伤的作用及其机制.方法 选择近交系雄性SD大鼠作为肝移植的供、受者;采用单纯随机方法将48只SD大鼠随机分为对照组、抑制组和诱导组(每组供、受者各8只).对照组:供肝不用任何药物处理;抑制组:在获取供肝前24 h,经供者腹腔注射HO-1抑制剂锌原卟啉20 mg/kg进行预处理;诱导组:在获取供肝前24 h,经供者腹腔注射HO-1诱导剂钴原卟啉5 mg/kg进行预处理.获取供肝后,在4℃UW液中冷保存24 h.肝移植前检测供肝HO-1的表达水平;肝移植后6 h采血并获取移植肝标本,分离培养枯否细胞;检测受者的肝功能;检测枯否细胞培养上清中肿瘤坏死因子α(TNF-α)和白细胞介素6(IL-6)的含量;观察移植肝组织病理学表现以及枯否细胞CD14 mRNA的表达水平和蛋白含量测定.结果 移植前诱导组供肝HO-1的表达水平明显增高.移植后诱导组血清丙氨酸转氨酶(ALT)和天冬氨酸转氨酶(AST)含量明显降低;移植肝组织病理学损伤减轻;枯否细胞培养上清中TNF-α和IL-6含量减少;而且枯否细胞上的CD14 mRNA表达水平和蛋白含量也明显低于抑制组.结论 诱导供肝HO-1表达上调可能抑制了枯否细胞的激活,从而减轻大鼠移植肝缺血再灌注损伤.

Effect and mechanism of Heme oxygenase-1 alleviating rat liver graft ischemia/reperfusion injury

Objective To explore the effect and mechanism of Heme oxygenase (HO)-1 alleviating rat liver graft ischemia/reperfusion (I/R) injury. Methods Inbred male SD rats were used as donors and recipients. Forty-eight SD rats were randomly divided into control group, suppression group and induced group (donors and recipients of each group were 8,respectively). In control group, no drugs were applied. In suppression group, donors received zinc protoporphyrin (ZnPP) (i. p. ,20 mg/kg), an HO-1 inhibitor 24 h prior to harvest. In induced group, donors received cobalt protoporphyrin (CoPP) (i. p. ,5 mg/kg), an HO-1 inducer 24 h prior to harvest. All livers were harvested and stored with UW solution at 4℃ for 24 h. HO-1 expression in the livers before transplantation was assessed. The rats in all groups were killed at the 6th hour after transplantation, and liver samples were collected, and Kupffer cells were isolated and cultured. Recipients' liver function was tested, and levels of cytokines (TNF-α and IL-6) in the culture supernatant was determined. Histopathological changes of the liver grafts were examined, and the expression of CD14 mRNA and protein in Kupffer cells was detected. Results The HO-1 expression in induced group before liver transplantation was significantly increased. Postoperatively, serum transaminases in induced group were significantly reduced,the histopathological lesions of the liver grafts alleviated,the levels of TNF-α and IL-6 in the culture supernatant of Kupffer cells decreased, and the expression levels of CD14 mRNA and protein in Kupffer cells significantly reduced as compared with the suppression group. Conclusion Induced liver HO-1 up-regulation may inhibit the activation of Kupffer cells,thereby reducing rat liver graft I/R injury.