凋亡相关分子的表达上调在免疫性肝损伤中的作用探讨

检测刀豆蛋白A(concanavalin A,ConA)诱导的小鼠急性肝损伤模型中凋亡相关分子的表达,并探讨其意义。以小鼠尾静脉注射15 mg/kg ConA建立急性肝损伤模型;AnnexinⅤ染色检测肝细胞的凋亡率;流式细胞术检测不同时间点肝细胞表面凋亡受体Fas、DR5的表达,以及肝浸润淋巴细胞表面凋亡配体FasL、TRAIL的表达。结果显示,与正常小鼠肝细胞凋亡率3.36%±0.69%相比,ConA诱导小鼠急性肝损伤后肝细胞的凋亡率显著上升,12 h为13.52%±0.68%,24 h达20.92%±0.66%。同时,肝细胞表面Fas、DR5的表达明显上升,肝浸润淋巴细胞表面FasL、TRAIL亦呈显著上调表达。结果表明,在ConA诱导的急性肝损伤发生发展过程中,肝细胞表面凋亡相关分子Fas、DR5与肝浸润淋巴细胞表面凋亡配体FasL、TRAIL的表达上调以及相互作用是导致肝损伤的重要因素。

Upregulated expression of apoptosis-associated molecules in ConA-induced liver injury

To determine whether the higher expression of apoptosis associated molecules on hepatocytes or liver infiltrating lymphocytes leading to the liver injury in ConA-induced hepatitis murine model,15mg/kg ConA was injected intravenously into BALB/c mice,liver injury was evaluated by serum transaminase assay and H-E staining.The apoptosis of hepatocytes was detected by flow cytometry via Annexin Ⅴ staining.The expression of Fas and DR5 on hepatocytes and the expression of FasL and TRAIL on liver-infiltrating lymphocytes were measured by FACS analysis too.Results showed that the apoptosis of hepatocytes was 13.52%±0.68% at 12 hours and 20.92%±0.66% at 24 hours after ConA injection,which were significantly higher than the control group.The Fas and DR5 positive hepatocytes were upregulated at 12 and 24 hours after ConA administration as compared with the control group.Simultaneously,the FasL and TRAIL expression of liver-infiltrating lymphocytes also increased at 12 and 24 hours after ConA administration as compared with the control group.Our data suggested that the increased proportion of apoptosis associated molecules on hepatocytes and liver-infiltrating lymphocytes might mediate the apoptosis of hepatocytes,consequently resulting in the liver injury.