全脑缺血再灌注后大鼠耳蜗组织内巢蛋白与神经生长因子的表达

Expressions of nestin and NGF of cochlea in rats after whole cerebral ischemia-reperfusion

目的：观察大鼠全脑缺血再灌注后耳蜗组织细胞巢蛋白（neuroepithelial stem protein,nestin）与神经生长因子（NGF）的表达。方法：66只健康SD大鼠随机分成正常组、假手术组、脑缺血再灌注组。采用四动脉闭塞法制作大鼠全脑缺血再灌注损伤模型,在脑缺血30 min再灌注后设置6 h、1 d、3 d、7 d、14 d 5个不同时间点,应用免疫荧光染色和免疫组化SABC法观察耳蜗组织细胞nestin与NGF的表达。结果：正常组和假手术组成年大鼠耳蜗组织细胞nestin不表达或微弱表达,NGF有适度表达。脑缺血再灌注后耳蜗组织nestin阳性表达1 d轻微增加,3 d明显增加,7 d达高峰,至14 d逐渐下降,但仍较假手术组高;NGF表达6 h即增加,1~3 d达高峰,7~14 d逐渐下降,但仍高于假手术组。结论：脑缺血再灌注能上调成年大鼠耳蜗组织细胞nestin与NGF的表达,诱导内源性耳蜗干细胞的原位激活。

Objective： To investigate the expressions of neuroepithelial stem cell protein（nestin） and nerve growth factor（NGF） in cochlear cells of rats after the whole cerebral ischemia/reperfusion.Methods： A total of 66 healthy Sprague-Dawley rats were randomly divided into the normal group,sham group,and cerebral ischemia/reperfusion（I/R） group.The whole cerebral ischemia/reperfusion injury models were established using the four-artery-occlusion-method.At the different time points of 6 h、1 d、3 d、7 d、14 d after 30 min of cerebral ischemia-reperfusion the expressions of nestin and NGF in cochlear cells were respectively observed with the methods of immunofluorescent staining and immunohistochemistry SABC.Results： Nestin had no expression or weak expressions and NGF moderate expressions within the cochleae cells of the adult rats in the normal group and sham group.After cerebral ischemia/reperfusion injury the nestin expression within cochlear tissue increased slightly in 1 day,increased markedly in 3 days,peaked in 7 days,then decreased gradually until at the 14th day,but were still higher than that in the sham group,and the NGF expression increased significantly in 6 h,increased markedly in 1 day,peaked in 3 days,decreased gradually during the 7th-14th days,but were still higher than that in the sham group.Conclusion： The study implies that cerebral ischemia/reperfusion can upregulate the expressions of nestin and NGF in cochleae cells of adult rats,and induce the in-situ activation of endogenous cochlear stem cells.