急性肝功能衰竭大鼠肝组织细胞因子信号转导抑制因子及肝细胞凋亡的动态变化

目的 建立急性肝功能衰竭（ALF）大鼠模型,观察其细胞因子信号转导抑制因子（SOCS）在肝组织中的表达及肝细胞凋亡的动态变化.方法 将雄性SD大鼠经腹腔注射D-胺基半乳糖（D-GaIN）800 mg/kg和LPS 8 μ g/只建立急性肝功能衰竭大鼠模型（模型组）,并设正常对照组,模型组分别于注射D-GaIN/LPS后2、6、12、24、48h时留取大鼠血及肝脏标本;同时采用免疫组化法检测大鼠肝组织中SOCS-1和SOCS-3蛋白表达;ELISA法测定血清TNF-α、tFN-γ水平;TUNEL法检测原位细胞凋亡.结果 模型组大鼠各时点的血清TNF-α、IFN-γ水平均较对照组增高（均P〈0.01）,且均于造模后6h时达峰值,后逐渐降低;模型组大鼠造模后6、12、24、48h时肝组织凋亡指数均高于对照组（均P〈0.05）;模型组大鼠各时点的肝组织SOCS-1和SOCS-3蛋白表达水平均较对照组明显增高（均P〈0.01）.且均于12 h达峰值,后逐渐降低.结论 急性肝功能衰竭可诱导体内SOCS表达上调,其改变可能与TNF-α、IFN-γ水平的变化及肝细胞凋亡密切相关,提示SOCS可能在急性肝功能衰竭的病理过程起重要作用.

Dynamic changes of cytokine signaling suppressors and hepatocyte apoptosis in rats with acute liver failure

Objective TO investigate the dynamic changes of cytokine signaling suppressors （SOCSs） expression and hepatocyte apoptosis in rats with acute liver failure （ALF）. Methods The ALF model was induced by intraperitoneal injection of D-galactosamine and lipopolysaccharide （D-GalN/LPS）. The serum and liver tissue samples were collected at 2h, 6h, 12h, 24h and 48h after D-GalN/LPS injection. The expressions of SOCS-1 and SOCS-3 proteins in liver tissue were detected by immunohistochemistry. The serum TNF-α and IFN-γ, levels were measured by ELISA. Hepatocyte apoptosis was examined by TUNEL assay. Results The serum levels of TNF-α and IFN-γ in ALF group were significantly increased and peaked at 6h, then gradually decreased. Compared with the control group, the serum levels of TNF-α and IFN-γ in ALF group were higher at each time points （all P〈0.01）. In ALF group, the apoptosis indices of liver cells at 6 h, 12h, 24h, and 48h were significantly higher than those in control group （all P〈0. 05）. The expressions of SOCS-1 and SOCS-3 were remarkably higher than those in control group and reached the peak at 12h （P〈0.01）, then gradually decreased. Conclusion There is a up-regulated expression of SOCSs in ALF, which is associated with serum TNF-α and IFN-γ levels and liver cell apoptosis. The results suggest that SOCSs may play an important role in the pathogenesis of acute liver failure.