Shh/Gli1信号通路在异氟醚后处理减轻大鼠脑缺血-再灌注损伤中的作用

目的评价Shh/Gli1信号通路在异氟醚后处理减轻大鼠脑缺血-再灌注损伤中的作用。方法清洁级健康雄性SD大鼠44只,6~8周龄,体重220~280 g,采用随机数字表法将其分为四组:假手术组(S组)、缺血-再灌注组(IR组)、缺血-再灌注+异氟醚后处理组(ISO组)和环巴胺+缺血-再灌注+异氟醚后处理组(CYC组),每组11只。采用线栓法栓塞大脑中动脉90 min、再灌注24 h制备脑缺血-再灌注损伤模型。ISO组大鼠在再灌注即刻吸入1.5%异氟醚。CYC组大鼠在缺血前30 min腹腔注射Shh/Gli1信号通路特异性抑制剂环巴胺10 mg/kg。再灌注24 h后,所有大鼠进行神经行为学评分,采用TTC法测定脑梗死体积,HE染色和尼氏染色观察病理学改变,TUNEL染色观察海马CA1区细胞凋亡,免疫荧光和Western blot法测定Shh和Gli1蛋白含量。结果与S组比较,IR组、ISO组和CYC组大鼠神经行为学评分明显升高,脑梗死体积明显增大,坏死和凋亡细胞明显增多,组织病理学损伤严重,Shh和Gli1蛋白含量明显增加(P<0.05)。与IR组比较,ISO组神经行为学评分和脑梗死体积明显降低,坏死和凋亡明显减少,组织病理学损伤明显减轻,Shh和Gli1蛋白含量明显增加(P<0.05)。与ISO组比较,CYC组神经行为学评分明显升高,脑梗死体积明显增大,坏死和凋亡细胞明显增多,组织病理学损伤明显加重,Shh和Gli1蛋白含量明显减少(P<0.05)。结论 Shh/Gli1信号通路激活参与了异氟醚后处理减轻大鼠脑缺血-再灌注损伤的过程。

Role of Shh/Gli1 signaling pathway in the treatment of cerebral ischemia-reperfusion injury after isoflurane post-conditioning in rats

Objective To evaluate the role of the Shh/Gli1 signaling pathway in the treatment of cerebral ischemia-reperfusion(IR) injury after isoflurane post-conditioning in rats. Methods Forty-four healthy male Sprague-Dawley rats, 6-8 weeks, weighing 220-280 g, were randomly divided into 4 groups(n=11 for each group): sham operation group(group S), ischemia-reperfusion group(group IR), ischemia-reperfusion+isoflurane post-conditioning group(group ISO) and cyclopamine+ischemia-reperfusion+isoflurane post-conditioning group(group CYC). Rats were subjected to middle cerebral artery occlusion for 90 min and reperfusion for 24 h. Group ISO received 1.5% isoflurane post-conditioning when reperfusion was initiated. In group CYC, the specific inhibitor of the Shh/Gli1 signaling pathway, cyclopamine, was injected at a dose of 10 mg/kg, 30 min before ischemia intraperitoneally. The neurobehavioral score was performed 24 hours after reperfusion. The cerebral infarction volume was determined by TTC method. The pathological results were observed by HE staining and Nissl staining. The apoptosis of hippocampus CA1 was observed by TUNEL staining. The expression levels of Shh and Gli1 were determined by immunofluorescence and Western blot. Results Compared with group S, the neurobehavioral scores, cerebral infarction volume, necrosis and apoptosis were significantly increased, histopathological damage was more sever, and Shh and Gli1 expression was significantly up-regulated in the groups IR, ISO and CYC(P < 0.05). Compared with group IR, the neurobehavioral scores and cerebral infarction volume were reduced significantly, necrosis and apoptosis were decreased, and the histopathological damage was further attenuated accompanying the highest expression levels of Shh and Gli1 in group ISO(P < 0.05). Compared with group ISO, neurobehavioral scores and cerebral infarction volume were raised significantly, necrosis and apoptosis were increased significantly, histopathological damage was aggravated significantly, as well as Shh and Gli1 expression levels were down-regulated significantly in group CYC(P < 0.05). Conclusion Activation of the Shh/Gli1 signaling pathway is involved in the treatment of cerebral IR injury after isoflurane post-conditioning in rats.