肝脏缺血再灌注对即早基因c-fos、c-jun表达影响的研究

Effects of hepatic ischemia/reperfusion on expression of immediate early genes c-fos and c-jun in rat

目的研究大鼠肝脏缺血再灌注中即早基因(c-fos,c-jun)表达的变化,以探讨其在细胞增殖和细胞凋亡中作用.方法选用大鼠原位肝部分缺血再灌注模型,缺血60min,于复灌后0、0.5、1、2、4、8、12和24h取材,RT-PCR检测不同时间点c-fos、c-jun mRNA的表达;应用流式细胞仪检测Ki-67抗原和Sub-G1,分别作为细胞增殖与细胞凋亡(Ap指数)的定量分析指标.结果血清ALT、AST随着复流时间的延长逐渐增高,在4 h左右达最高峰,而后渐下降,至24 h达到基线水平;Ki67在复灌后1 h开始增高,持续到24 h;在复灌后肝细胞凋亡率Ap指数也逐渐增高,峰值于复灌后12 h出现;再灌注后0.5～2.0 hc-fos和c-jun的表达均增高,1 h达高峰;4h后只有c-jun有持续较高的表达,c-fos的表达开始下降.结论缺血再灌注过程中,肝细胞的凋亡与增殖是同时存在的.c-fos和c-jun在再灌注早期和后期两种不同的表达模式提示:c-fos和c-jun共表达可能与组织修复有关,而c-jun的持续高表达可能引起细胞的凋亡.

Objective The purpose of this research was to investigate the expression of immediate early genes c-fos and c-jun following hepatic ischemia/r eperfusion(IR) and its roles in cellular regeneration and apoptosis. Methods Fifty-four Wistar rats were randomly divided into nine groups: SO, 0, 0.5, 1, 2 , 4, 8, 12, 24 h. The model of partial liver ischemia/reperfusion was used. 60 m inutes ischemia, After 0, 0.5, 1, 2, 4, 8, 12, 24 h reperfusion, the serum and l iver tissue in each group were collected to detect the serum ALT/AST , liver his topathology, expression of c-fos and c-jun mRNA. Flow cytometer was used to dete ct Ki67 and Sub-G1 as the quantity indicators of cell regeneration and apotosis respectively. Results The serum ALT and AST elevated gradually as reperfusio n time extending, reached its peak level about 4 hours, then decreased to base l evel about 24 hour. Ki67 elevated after 1 hour reperfusion, sustained high level to 24 hour. Ap index elevated gradually after reperfusion, its peak level occur red about 12 hours. Co-expression of both c-fos and c-jun occurred during 0.5 to 2 hour reperfusion, its peak time both in 1 hour, then with a decline in c-fos expression and sustained high level of c-jun expression after 4 hour. Conclusi on During liver ischemia/reperfusion, hepatocytes regeneration and apoptosis a re coexisted. Two distinct patterns of c-fos and c-jun expression are observed d uring acute(0.5~2.0 hours) and subacute (4~24 hours) phases of liver responses t o IR, these findings indicate coexpression of c-fos and c-jun may be involved i n tissue repair processes, while sustained high level expression of c-jun may be lead to apoptosis.