摘要
目的观测慢性脑灌注不足(CVI)大鼠海马区早老素-1(PS-1)基因及其蛋白产物的动态表达,以探讨脑缺血对PS-1表达的影响。方法110只雄性W istar大鼠,随机分为对照组及CVI组,每组55只。根据手术后不同时间再将大鼠分为术后3、6、12 h,1、2、3、7、14 d和1、2、4个月组,每组5只。结扎双侧颈总动脉建立CVI模型,于术后规定时间取脑组织,行原位杂交及W estern印迹检测PS-1基因及其蛋白产物的表达。结果PS-1 mRNA阳性细胞主要是神经元,在大脑皮质Ⅲ、Ⅴ层锥体细胞染色最强;海马CA3、齿状回的表达比CA1区更强。与对照组相比,CVI组随着缺血时间的延长,阳性细胞数量减少,结构欠清晰,呈固缩或均匀着色,但明显的细胞坏死改变较少见;组织明显疏松。半定量分析表明,与对照组比较,CVI组阳性细胞积分光密度从第12小时开始升高(7 423±1 609对6 889±2 296),至第3天达高峰(13 356±3 503对7 201±2 239,P<0.01),之后逐渐下降至接近或略低于对照组水平。在缺血时间更长的CVI组中,齿状回PS-1mRNA阳性神经元数量较CA1区保留更多。W estern印迹结果与PS-1 mRNA的变化近似,与对照组积分光密度(183±36)比较,PS-1蛋白含量于双侧颈总动脉结扎术后第12小时轻度升高(249±57),第3天达高峰(966±178),第14天下降至对照组水平,1个月后略低于对照组(103±25)。结论脑缺血可以通过影响PS-1的表达促进缺血性脑损伤。
Objective To observe presenilin-1 （PS-1） gene and its dynamic expression of protein product in chronic cerebrovascular insufficiency （CVI） in rats and to explore the effect of cerebral ischemia on the expression of PS-1. Methods A total of 110 male Wistar rats were randomly allocated into control （n =55） and CVI （n = 55 ） groups, and each group was redivided into the following postoperative time groups： 3, 6, 12 hours, and 1, 2, 3, 7, 14 days, and 1, 2, 4 months （n=5 in each group）. CVI model was established by the ligation of bilateral common carotid arteries. Brain tissues were taken out at the fixed points of time; in situ hybridization and Western blot were performed. Results Neurons were the mostly PS-1 mRNAs positive cells. Pyramidal cell staining was most intensive in layers Ⅲ or Ⅴ ; and the expressions of hippocampus CA3 and dentate gyrus were more intensive than CA1. The numbers of positive cells decreased with the lapse of time compared with the control group, and their structures were less clear, pyknosis and homogeneous staining, but the severe cytonecrosis was uncommon, and tissue rarefaction was severe. Semi-quantitative analysis showed that the integra optical density began to increase from 12 hours （as compared with the control group 7 423 ± 1 609 vs 6 889 ± 2 296）, and it increased to the peak at day 3 （ 13 356 ±3 503 vs 7 201 ±2 239, P 〈0. 01 ）. Then it gradually decreased almost to the levels of the control group or slightly lower than that. In the CV1 group with longer ischemia, the numbers of dentate gyrus PS-1 mRNA positive neurons were more than those in CA1. Western Blot result has analogous changes compared with the changes of PS-1 mRNA. Compared with control group （ 183 ±36）, PS-1 protein content slightly increased （249 ±57） 12 hours after bilateral ligation of common carotid arteries. It increased to the highest （ 966 ± 178） at day 3, and decreased to the levels of the control group at day 14, and was lower than the control group 1
出处
《中国脑血管病杂志》
CAS
2006年第6期273-277,共5页
Chinese Journal of Cerebrovascular Diseases
关键词
脑损害
慢性
海马
早老素-1
大鼠
Brain damage, chronic
Hippocampus
Presenilin-1
Rats
