重组腺病毒介导的血管生长素基因转染对大鼠局灶性脑缺血的治疗作用

Recombinant adenoviral vector-mediated gene transfer of angiogenin enhances brain repair following ischemia-reperfusion injury in rat

目的观察重组腺病毒介导的血管生长素(ANG)基因转染对局灶性脑缺血再灌注大鼠脑组织的作用。方法制备重组血管生长素腺病毒(Ad-ANG,含绿色荧光蛋白基因)及重组绿色荧光蛋白腺病毒(Ad-GFP)。清洁级雄性SD大鼠随机分成Ad-ANG治疗组和Ad-GFP对照组。线栓法制作脑缺血再灌注模型,缺血90min再灌24h后两组大鼠分别侧脑室注射Ad-GFP或Ad-ANG。Longa法观察两组大鼠神经功能缺失评分;于注射后1d、3d、7d和14d制备脑组织冰冻切片,观察脑内绿色荧光蛋白表达情况,并进行HE染色、vWF因子免疫组化染色、ANG免疫组化染色及细胞凋亡检测。结果 Ad-ANG治疗组在治疗后3d、7d神经功能缺失评分较Ad-GFP对照组有明显改善(P<0.05);两组大鼠侧脑室注射重组腺病毒后1d、3d时荧光显微镜下可见室管膜周围及脉络丛有较强的绿色荧光;HE染色可见Ad-ANG治疗组皮层神经元结构清晰,间质水肿、核固缩、核溶解程度较对照组明显减轻;ANG免疫组化结果显示Ad-ANG治疗组大鼠缺血脑组织ANG阳性细胞数在观察各时间点均显著高于Ad-GFP对照组(P<0.01);vWF染色及凋亡检测显示3d、7d、14d时Ad-ANG治疗组大鼠缺血侧脑内微血管密度显著高于Ad-GFP对照组(P<0.01),凋亡细胞数显著少于Ad-GFP对照组(P<0.05)。结论侧脑室注射方式转染Ad-ANG能使脑缺血大鼠脑内ANG阳性细胞数增加,并促使缺血脑区血管生成,减少神经元的凋亡,促进神经功能的恢复,对缺血再灌注损伤脑组织有保护作用。

Objective To observe the effects of angiogenin（ANG） gene transfection into lateral cerebral ventricle against acute ischemia/reperfusion injury in rats.Methods Prepare recombinant angiogenin adenovirus（including green fluorescent protein gene,Ad-ANG） and green fluorescent protein recombinant adenovirus（Ad-GFP） were prepared.Male adult SD rats were randomly divided into ANG group and GFP group.Transient（90min） focal cerebral ischemia was induced by middle cerebral artery occlusion（MCAO）.Ad-ANG or Ad-GFP was injected respectively into the lateral cerebroventricle of the rats at 24h after reperfusion.Neurological deficits were observed in different groups.Rats were sacrificed at in 1d,3d,7d and 14d after injection for fluorescence detection.HE staining,immunohistochemical and TUNEL studies were preformed.Results ANG improved neurological deficits（P〈0.05） in 3d,and 7d group.GFP expression distributed apart from the ventricle and reached a peak at on 3 days ANG inhibited the neuronal deformation shown by HE staining.In Ad-ANG group,ANG-positive cells distinctly increated（P〈0.01） at each time point,MVD significantly increased（P〈0.01） in 3d,7d,and 14d group,and TUNEL-positive cells were less（P〈0.05） than the control group in 3d,7d,and 14d group.Conclusion Intraventricular injection of ANG mediated by recombinant adenoviusl upregulated brain ANG protein level in ischemical brain of adult rat,boosted angiogenesis,reduced neuronal apoptosis and expedited the recovery process of neurologic deficit.It played plays neuroprotective roles in pathophysiological process following cerebral ischemic injury in rats.