局灶脑缺血神经细胞和星形胶质细胞可能不同死亡途径探讨  

Different cell death pathway in neurons and astrocytes after focal cerebral ischemia

作　　者：付学军[1] 褚晓凡[1] 邹良玉[1] 亓传洁[1] 饶宜光[1] 

机构地区：[1]暨南大学医学院第二临床学院神经内科,广东深圳518020

出　　处：《中风与神经疾病杂志》2011年第7期623-627,共5页Journal of Apoplexy and Nervous Diseases

摘　　要：目的本研究采用电镜和免疫组化的方法观察局灶脑缺血中心区和边缘区细胞死亡形态学变化特征,探讨神经细胞和星形胶质细胞可能存在的不同死亡途径。方法 78只SPF级雄性SD大鼠,随机分为:(1)假手术组6只;(2)电镜对照组2只;(3)免疫组化组30只;(4)电镜实验组10只。3、4组大鼠分别于缺血3h、6h、12h、24h、48h取脑,假手术组和对照组为术后24h取脑。HE染色,GFAP和TUNEL染色,GFAP、TUNEL双标免疫组化染色,图像分析观察上述指标表达情况。结果随缺血时间延长,电镜下可见缺血中心区星形胶质细胞明显肿胀,缺血12h星形胶质细胞核膜破溃,染色质漏出。而神经元电子密度增高,细胞核变形、固缩。缺血24h可见凋亡小体。缺血边缘区各时间点神经细胞的损伤程度呈明显的不一致性。免疫组化显示缺血3h中心区及边缘区均可见TUNEL阳性细胞,以边缘区为主,随缺血时间延长边缘区阳性细胞渐增多,中心区TUNEL阳性细胞递减,缺血24h后中心区罕见阳性细胞。缺血6h中心区GFAP阳性细胞明显减少,缺血12h中心区罕见阳性细胞,缺血24h后边缘区可见大量GFAP阳性细胞与中心区形成明显的阴阳分界线。GFAP和TUNEL双标染色各时间点均未见双标阳性细胞。结论凋亡可能是神经元细胞的主要死亡途径。而星形胶质细胞缺血后未见GFAP和TUNEL双标染色阳性细胞,可能是沿胀亡的途径走向死亡。Objective Electron microscopy and immunohistochemistry were used to investigate the morphological changes of cell deaths in core region and marginal region of focal cerebral ischemia.Possible death pathways in neurons and astrocytes were explored.Methods 78 male SD rats were randomly divided into 4 groups,sham-operation group（6 rats）,electron microscope control group（2 rats）,immunohistochemistry experiment group（30 rats） and electron microscope experiment group（10 rats）.The brain samples of immunohistochemistry experiment group and electron microscope experiment group were obtained at 3h,6h,12h,24h and 48h after embolization,respectively.HE and GFAP staining,TUNEL and GFAP-TUNEL double labeled immunohistochemistry analysis were applied.Routine electron microscopic technology was also used to evaluate morphologic changes as well.Results Astrocytes in the core region became more swollen as the time of ischemia went on.After 12h ischemia,nuclear membrane cracked and chromatin leakage happened in astrocytes without coagulability changes.In neurons,cell nucleus deformation and karyopycnosis along with apoptotic bodies were observed.The degrees of cell injury in the marginal region of ischemia at different time point were not of concordance.TUNEL positive cells were seen in central and marginal regions 3h after ischemia,mainly in marginal region,and were more as ischemia went on while decreased in core area.After 24h ischemia,TUNEL positive cells could scarcely be seen in core region.GFAP positive cells were decreased in core region after 6h ischemia and scarcely seen after 12h ischemia.In marginal region after 24h ischemia a number of GFAP positive cells were seen which drawed an apparent dividing line contrasted to the central region.GFAP and TUNEL double labeling positive cells were not seen at every time point.Conclusion Continuous ischemia can cause neuron in both core and marginal area coagulation death.Apoptosis may be main death pathway for neuron.As for astrocytes,swellen death was in both area

关 键 词：神经细胞 星形胶质细胞 死亡途径 凋亡 胀亡 

分 类 号：R7[医药卫生—临床医学]