凝血酶诱导小胶质细胞激活与黑质多巴胺能神经元变性关系的研究  

Neurotoxicity effect on dopaminergic neurons and activated microglia induced by thrombin

作　　者：黄承芳[1] 黎钢 马嵘[2] 孙圣刚[1] 方瑗[1] 魏桂荣[1] 

机构地区：[1]华中科技大学同济医学院附属协和医院神经内科,武汉430022 [2]华中科技大学同济医学院药理系

出　　处：《卒中与神经疾病》2008年第4期199-203,共5页Stroke and Nervous Diseases

基　　金：国家自然科学基金资助(30500574)

摘　　要：目的探讨凝血酶诱导小胶质细胞激活与黑质多巴胺(DA)能神经元变性的关系。方法采用脑立体定向术将凝血酶注射入大鼠黑质,采用尼氏(Nissl)染色、酪氨酸羟化酶(TH)及特异性小胶质细胞表面补体受体(CR3)单克隆抗体(OX-42)标记免疫组织化学染色,观察凝血酶注射入大鼠黑质后不同时间点TH阳性多巴胺能神经元数量及小胶质细胞的激活情况。结果凝血酶注入黑质4h后小胶质细胞开始呈现"灌木丛样"或少量呈现阿米巴样;12h小胶质细胞数目明显增加且绝大部分呈现阿米巴样;24h已完全激活,"阿米巴样"细胞达高峰;3d维持高峰;14d后小胶质细胞染色变淡,体积变小,阿米巴样细胞数目下降。TH阳性细胞数在第3d开始下降,第7d有大量的TH阳性细胞丢失,与对照侧相比下降达约53%(P<0.01),高倍镜下可见胞体皱缩、突起明显缩短或减少,14d时细胞数下降至21%,30d时约为12%(P<0.01)。结论凝血酶对DA能神经元具有一定的损毁作用,小胶质细胞的激活先于DA能神经元变性,其活化可能参与DA能神经元变性。Objective To explore the relationship between the activities of microglia and the degeneration effects of thrombin on substantia nigra dopaminergic neurons. Methods After thrombin was stereostatically injected into unilateral substantia nigra of rats, at the different survial time, specific antibody OX-42 was used to detect changes of morphology and the numbers of microglia; the damage of the substantia nigra DA neurons was observed by using tyrosine-hydroxylase （TH） immunohistochemical staining and Nissl body staining. Results On the control side of the substantia nigra, all of the OX-42 positive microglia exhibited the typical ramified resting stage. In marked contrast, however, thrombin triggered profound activation of microglia in the SN, with enhanced staining intensity and activated morphology in OX-42 immuno-positive cells. At 4 h post-injection, A portion of the OX-42 immuno-positive cells started to be activated and appeared to be ＂bushy＂, and a small quantity of microglia became fully activated with the characteristic ＂amoeboid＂ morphology. At 12 h, most microglia were activated with the characteristic ＂amoeboid＂ morphology. At 24 h, nearly all of the positive microglia became fully activated with the characteristic ＂amoeboid＂ morphology. At 3 d. microglia remained at the peak stage of full activation. Surprisingly, the subsequent 14 d was found to dramatically mitigate the number of ＂amoeboid＂ morphology cells and emerge many ＂bushy＂ cells in the SN. Correlatively, Compared with the control groups, the number of TH positive neurons began to decrease on the 3 d after postinjection, and 7 d later, In highly magnified photographs, thrombin-induced degenerating neurons appeared as shrunken and rounded cell bodies with few processes, the decrease was 53% （P〈0.01）, and the number was 21% on the 14 d and about 12% on the 30 d （P〈0. 01）. Conclusions Thrombin intranigral injection can injure the dopaminergic neurons in the SN. Activation of microglia plays an important ro

关 键 词：凝血酶 多巴胺能神经元 小胶质细胞 帕金森病 

分 类 号：R742.5[医药卫生—神经病学与精神病学]