依达拉奉通过上调LMO4表达保护大鼠脑缺血再灌注损伤

Edaravone protects against cerebral ischemia-reperfusion injury in rats by upregulation of the LMO4 expression

目的探讨依达拉奉对脑缺血再灌注大鼠的神经保护机制。方法健康成年雄性SD大鼠36只，随机分为假手术组（n＝12）、模型组（n＝12）和依达拉奉组（n＝12）。采用线栓法制作局灶性脑缺血再灌注模型，缺血2 h后恢复灌注，再灌注24 h后处死动物。依达拉奉组在脑缺血再灌注即刻腹腔注射依达拉奉3 mg/kg，模型组注射等体积生理盐水。采用HE染色观察病理学改变，TUNEL染色检测缺血皮质凋亡细胞，蛋白质印迹法和免疫荧光染色检测缺血皮质LIM结构域蛋白4（LIM domain protein 4, LMO4）表达水平和阳性细胞。结果HE染色显示，假手术组细胞形态基本正常；模型组和依达拉奉组均有细胞坏死，但后者程度减轻，形态正常的细胞数量显著增多于前者（P〈0.01）。TUNEL染色显示，假手术组未见TUNEL阳性细胞；依达拉奉组缺血皮质TUNEL阳性细胞显著少于模型组（P〈0.01）。免疫荧光染色显示依达拉奉组缺血皮质LMO4阳性细胞显著多于模型组（P〈0.01），蛋白质印迹分析显示依达拉奉组缺血皮质LMO4表达水平显著高于模型组（P〈0.01）。结论依达拉奉可减轻脑缺血再灌注损伤，抑制神经细胞凋亡，其机制可能与上调LMO4表达有关。

ObjectiveTo investigate the neuroprotective mechanism of edaravone for cerebral ischemia-reperfusion injury in rats. MethodsThirty-six healthy adult male SD rats were randomly divided into three groups： a sham operation group, an ischemic model group, and an edaravone group （n=12 in each group）. A focal cerebral ischemia model was induced by the suture method. Reperfusion was resumed after 2 h of ischemia; then the animals were sacrificed at 24 h after reperfusion. Edaravone 3 mg/kg was injected intraperitoneally immediately after cerebral ischemia-reperfusion in the edaravone group. The rats in the model group were injected equal volume normal saline. HE staining was used to observe the pathological changes. TUNEL staining was used to detect apoptotic cells in the ischemic cortex. Western blot and immunofluorescent staining were used to detect the expression levels of LIM domain protein 4 （LMO4） and LMO4 positive cells.ResultsHE staining showed that cellular morphology was basically normal in the sham operation group; both the model group and edaravone group had cell necrosis, but the latter was less severe. The number of morphologically normal cells in the edaravone group was significantly more than that in the model group （P〈0.01）. TUNEL staining showed that no TUNEL positive cells in the sham operation group were observed. The TUNEL positive cells in the edaravone group was significantly less that in the model group （P〈0.01）. Immunofluorescence staining showed that the expression level of LMO4 in the ischemic cortex in the edaravone group was significantly higher than that in the model group （P〈0.01）.ConclusionsEdaravone can alleviate the cerebral ischemia-reperfusion injury and inhibit neuronal apoptosis. Its mechanism may be associated with the upregulation of LMO4 expression.