JAK2/STAT1信号通路对大鼠肝脏冷缺血及再灌注后急性肾损伤的影响

Effect of JAK2/STAT1 on acute kidney injury induced by liver cold ischemia reperfusion in rats

目的 探讨Janus激酶2/信号转导和转录激活子1（JAK2/STAT1）信号通路在大鼠肝脏冷缺血及再灌注后肾损伤中的作用及机制.方法 健康雄性SD大鼠30只,采用随机数字表法将其分为3组,每组10只：（1）IR组：建立大鼠肝脏冷缺血再灌注模型;（2）AG490组：建立大鼠肝脏冷缺血再灌注模型,建模前30 min腹腔注射JAK2特异性抑制剂AG490 10 mg/kg;（3）假手术组：大鼠仅开腹,游离肝脏周围血管及韧带后关腹.再灌注后6 h（假手术组术毕后6 h）,检测各组大鼠肾功能,肾组织氧化应激水平,HE染色法观察肾组织病理学改变,采用原位末端标记法检测肾组织细胞凋亡情况,采用蛋白质印迹法检测p-JAK2、p-STAT1及Bcl-2、Bax的蛋白水平.结果 与假手术组比较,IR组大鼠肾功能明显降低,肾病理损伤严重,肾组织氧化应激及细胞凋亡明显增加,Bcl-2/Bax比值显著降低,以及JAK2和STAT1磷酸化显著上调（P＜0.05）;与IR组比较,AG490组大鼠肾损伤减轻,肾功能得到明显改善,氧化应激水平降低,细胞凋亡显著减少,以及Bcl-2/Bax比值显著升高（P＜0.05）,与此同时,JAK2和STAT1磷酸化水平显著下调（P＜0.05）.结论 抑制JAK2/STAT1信号通路可以缓解大鼠肝冷缺血再灌注后急性肾损伤,其作用机制可能与减轻氧化应激反应及细胞凋亡水平等有关.

Objective To investigate the effect of Janus kinase2/signal transducer and activator of transcription 1 （JAK2/STAT1） signaling pathway on acute kidney injury induced by liver cold ischemia reperfusion （IR） in rats.Methods Thirty healthy male Sprague-Dawley rats,weighing 220-250 g,were assigned randomly to 3 groups （n =10/group）：sham operation group （Sham group）;liver cold ischemia reperfusion model group （I/R group）;JAK2 kinase inhibitor AG490 group （AG490 group） （AG490 at dose of 10 mg/kg was intraperitoneally injected 30 min before establishment of the model）.Other groups were given the equal volume of normal saline at the same time points.Then the rats were sacrificed at 6 h after reperfusion （at 6 h after the end of operation in Sham group）.The renal function and oxidative stress level were observed.The pathological changes of the renal tissues and nephritic cell apoptosis were analyzed,and the expression of p-JAK2,pSTAT1,Bcl-2 and Bax was detected by Western blotting.Results As compared with Sham operation group,renal histological lesion and renal dysfunction were aggravated,level of oxidative stress and apoptosis rate were increased in I/R group,the Bcl-2/Bax ratio was decreased and the expression of pJAK2 and p-STAT1 was up-regulated.As compared with I/R group,AG490 dramatically attenuated histological lesions and oxidative stress,restored the renal function,and reduced the number of apoptotic tubular epithelial cells.AG490 significantly increased the Bcl-2/Bax ratio,and inhibited the expression of p-JAK2 and p-STAT1.Conclusion Blockage of JAK2/STAT1 signaling pathway can alleviate acute kidney injury after liver cold ischemia reperfusion probable through inhibiting the oxidative stress and apoptosis.