摘要
目的:观察大鼠局灶性脑缺血再灌注后细胞周期蛋白D1(CyclinD1)mRNA的表达与神经细胞凋亡的关系以及肌苷的干预作用,从细胞增殖角度探讨肌苷的神经保护作用机制。方法:应用线栓法建立大鼠大脑中动脉阻塞(MCAO)再灌注模型,腹腔注射肌苷注射液,应用原位末端标记(TUNEL)和原位杂交技术分别检测大鼠脑缺血再灌流不同时间点皮质区和纹状体区神经细胞CyclinD1mRNA的表达与凋亡的变化。结果:脑缺血再灌注2h后皮质区与纹状体区即出现少量凋亡神经细胞,皮质区1d达高峰(72.8±2.66)个/视野,纹状体区2d达高峰(96.75±4.37)个/视野,之后逐渐减少,至再灌注14d(5.50±0.65)个/视野接近假手术组水平(3.75±0.85)个/视野;肌苷治疗组凋亡神经细胞较对照组显著减少;脑缺血再灌流后皮质区与纹状体区的缺血周围区神经细胞CyclinD1mRNA的表达于2h逐渐增强,皮质区和纹状体区分别于12h和1d达高峰,以后逐渐下降;肌苷治疗组CyclinD1mRNA表达较对照组显著减弱。结论:脑缺血再灌流CyclinD1mRNA的表达时序先于凋亡细胞的出现,其异常表达可能诱导了神经元的凋亡。肌苷可在脑缺血再灌注后抑制CyclinD1mRNA的表达,从而减少神经细胞凋亡,起到神经保护作用。
AIM: To investigate the relationship between the expression of Cyclin D1 mRNA and neuronal apoptosis after focal cerebral ischemic reperfusion and the interv ention of inosine in rats and to explore the action of inosine in protection ner ve based on the cell proliferation. METHODS:The model of the focal ischemic reperfusion in SD rats was induced by intraluminal middle cerebral artery occlusion(MCAO) with a nylon monofilament s uture. The rats of the inosine group were injected with inosine(100 mg/kg) intra peritoneally twice before and 12 hours after reperfusion. In situ hybridization was performed to examine the expression of Cyclin D1 mRNA in the cortox and stri atum.At the same time,the neuronal apoptosis was also detected by TUNEL staining . RESULTS:TUNEL-positive neuons appeared at 2 h and peaked significantly at 1 d in the cortex[(72.80± 2.66) pieces/visual field] and at 2 d [(96.75± 4.37) pieces/visual field] in the striatum after reperfusion,and then began to decreas e gradually at 14 d[(5.50± 0.65) pieces/visual field] to the level of the sham operation group [(3.75± 0.85) pieces/visual field].More apoptostic nerve cells were found in the inosine group than in the control group.Cyclin D1 mRNA express ion increased in the cortex and the striatum of ischemic hemisphere as early as 2 h after reperfusion and reached a peak at 12 h and 1 d in the cortex and the s triatum respectively,and then also began to decrease gradually.The expression of Cyclin D1 mRNA in the inosine group decreased significantly as compared with th at in the control group. CONCLUSION:The expression of Cyclin D1 mRNA occurred earlier than the cell ap optosis.The abnormal expression of Cyclin D1 mRNA maybe induce the apoptosis of neurons. Inosine might reduce the neuronal apoptosis for the protection of nerve through down-regulating the expression of Cyclin D1.
出处
《中国临床康复》
CSCD
2004年第4期670-671,共2页
Chinese Journal of Clinical Rehabilitation
基金
山东省自然科学基金
青岛市科技局资助项目(Y2001C04)~~
