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背景:细胞凋亡是缺血再灌注损害的重要形式之一,白细胞介素1β转化酶是细胞凋亡关键调节因子,其激活可导致蛋白降解引起细胞凋亡。目的:观察在脑缺血再灌注过程中白细胞介素1β转化酶基因的表达及其与细胞凋亡的关系,探讨其在调控脑缺血后细胞凋亡中的作用。设计:随机对照试验。材料:实验于1996-03/2000-12在解放军第三军医大学神经科学中心完成。选择成年W istar大鼠64只,随机分为2组,脑缺血再灌注组:采用四血管阻塞全脑缺血模型,缺血30m in 后再灌注,根据处死时间分为再灌注3,6,12,24,48,72h 和7d 共7个时间点,每个时间点8只。假手术组8只,仅分离,未夹闭双侧颈总动脉。方法:假手术组和脑缺血再灌注组再灌注后每个时间点随机选取4只大鼠采用免疫组化和原位杂交检测。其余4只用于原位末端标记检测。主要观察指标:①各组大鼠脑组织白细胞介素1β转化酶蛋白和m RNA的表达。②各组大鼠脑组织神经细胞凋亡情况。结果:64只大鼠全部进入结果分析。①各组大鼠脑组织白细胞介素1β转化酶m RNA 和蛋白的表达:假手术组脑组织多数脑区白细胞介素1β转化酶mRNA 和蛋白有少量表达,脑缺血组白细胞介素1β转化酶m RNA 和蛋白在神经元内及小胶质细胞均有表达,分布在大脑皮质、小脑蒲肯野细胞、海马及皮质下白质。在缺血再灌注12h 后白细胞介素1β转化酶基因表达增加,48～72h 为表达高峰,第7天表达下降。②各组大鼠脑组织神经细胞凋亡情况:细胞凋亡在缺血再灌注12h 出现犤(49.4±6.8)个/切片犦,高峰时间在72h犤(228.6±29.8)个/切片犦,且白细胞介素1β转化酶蛋白和m RNA 的表达在分布上与神经细胞凋亡的发生有显著相关性(r=0.89,0.68,P <0.05)。结论:①白细胞介素1β转化酶蛋白和m RNA 的表达增加,与缺血后细胞凋亡有显著相关性,从时间上支持白细胞介素1β转化酶表达是导致细胞凋亡的重要因素。②在脑缺血再灌注过程中大脑皮质、海马及基底节区是凋亡细胞的多发部位,而这些部位也是白细胞介素1β转化酶表达增高的区域,进一步证明缺血后白细胞介素1β转化酶的表达参与神经细胞凋亡的调节。
BACKGROUND: Apoptosis is one of the important forms of ischemia-reperfusion injury. Interleukin-1β converting enzyme is a key regulatory factor of apoptosis. Its activation can cause protein degradation and cause apoptosis. OBJECTIVE: To observe the expression of interleukin-1β (TGF-β1) converting enzyme gene and its relationship with apoptosis in the process of cerebral ischemia-reperfusion, and to explore its role in the regulation of apoptosis after cerebral ischemia. Design: Randomized controlled trial. MATERIALS: Experiments were performed at the Neuroscience Center of the Third Military Medical University of Chinese PLA from March 1996 to December 2000. Sixty-four adult Wistar rats were randomly divided into 2 groups. Cerebral ischemia-reperfusion group: The model of occlusion of the whole blood was established by four-vessel occlusion. After ischemia for 30 min, reperfusion was performed. , 12,24,48,72h and 7d a total of seven time points, each time point 8. Sham operation group 8, only isolated, unilateral bilateral common carotid artery. Methods: Sham operation group and cerebral ischemia-reperfusion group were randomly selected after reperfusion at each time point 4 rats were detected by immunohistochemistry and in situ hybridization. The remaining 4 were used for in situ end-labeling detection. MAIN OUTCOME MEASURES: ① The expression of interleukin-1β converting enzyme protein and m RNA in the brain of rats in each group. ② neuronal apoptosis in brain tissue of rats in each group. Results: All 64 rats entered the result analysis. (1) The expression of interleukin-1β converting enzyme (m RNA) and protein in the brain tissue of rats in each group: The expression of interleukin-1β converting enzyme mRNA and protein in most brain regions of sham-operation group was low, while the expression of interleukin- Enzymes m RNA and protein are expressed in neurons and microglia, distributed in the cerebral cortex, cerebellum Purkinje cells, hippocampus and subcortical white matter. The expression of interleukin 1 beta converting enzyme gene increased after 12 h of ischemia reperfusion, peaked at 48 ~ 72 h and decreased at 7 d. ② Apoptosis of nerve cells in brain tissue of rats in each group: 细 (49.4 ± 6.8) cells / section 12, peak time at 72h 犤 (228.6 ± 29.8) / section 12 after ischemia-reperfusion 12h The expression of interleukin 1 beta converting enzyme protein and m RNA were significantly correlated with the occurrence of neuronal apoptosis (r = 0.89,0.68, P <0.05). Conclusion: ①The expression of interleukin-1β converting enzyme protein and m RNA is increased, which is significantly correlated with the apoptosis after ischemia. It is an important factor that leads to the apoptosis that the expression of interleukin-1β converting enzyme is supported in time. ② Cerebral cortex, hippocampus and basal ganglia were the multiple sites of apoptotic cells in the process of cerebral ischemia-reperfusion, and these sites were also the regions of increased expression of interleukin-1β converting enzyme, which further proved that the interleukin 1β Enzyme expression is involved in the regulation of neuronal apoptosis.