大鼠肝脏缺血再灌注对JNK通路表达影响的研究

Role of JNK cascade pathway in hepatic ischemia/reperfusion injury in rat

目的观察肝缺血再灌注对JNK通路中JNK活化的情况和c-junmRNA表达的影响,以探讨其在肝脏缺血再灌注损伤中的作用。方法60只Wistar大鼠随机分成缺血再灌注组(IR),与假手术组(SO组),利用肝原位部分缺血再灌注模型,于复灌后0、0.5、1、2、4、8、12和24h取材,应用免疫组织化学的方法对磷酸化的JNK(p-JNK)进行免疫组化检测以及RT-PCR法检测各组c-junmRNA的表达,并作半定量分析,观察其在缺血再灌注中的变化。结果p-JNK在缺血后即有轻度地增高,但在再灌注后30min开始增高明显,持续到再灌注后4h,高峰出现在再灌注后2h。在IR组再灌注后0.5～2hc-junmRNA的表达增高,1h达高峰;4h后c-junmRNA仍有持续较高的表达。结论缺血再灌注可以增加JNK的磷酸化水平以及c-junmRNA的转录水平,JNK通路可能在缺血再灌注损伤中取至关重要的作用。

[Objective] To study activation of JNK and transcription of c-jun mRNA in hepatic ischemia-reperfusion, in order to explore its roles in hepatic ischemia-reperfusion injury. [Methods] The orthotopic partial hepatic ischemia/reperfusion animal model was used. 60 Wistar rats were randomly divided into group ischemia/reperfusion （IR）, and group sham operation （SO）. Liver tissue was harvested at 0, 0.5, 1, 2, 4, 8, 12 and 24 h after ischemia] reperfusion. The phosphorylated JNK was detected by immunohistochemistry and c-jun mRNA was detected by RT- PCR, half-quantitative analysis was made to study its expression changes in IR settings. [Results] Phospho-JNK increased slightly after ischemia and increased significantly at 30 minutes after reperfusion in IR group, the high level was kept to 4 hours after reperfusion, and its peak time occurred at 2 hours after reperfusion. The expression mRNA of c-jun increased from 0.5h to 2 h, reached peak level at 1 h, and kept high expression after 4 h reperfusion. [Conclusion] Ischemic reperfusion can increase the phosphorylation level of JNK and transcription level of c- jun mRNA. These results suggest that JNK cascade pathway may play a vital role in the ischemia-reperfusion injury.