促红细胞生成素对慢性脑缺血大鼠脑组织促凋亡相关蛋白表达水平的影响

Influences of Erythropoietin on Expression Level of Proapoptotic Protein in Brain Tissue of Rats with Chronic Cerebral Ischemia

目的探讨促红细胞生成素(EPO)对慢性脑缺血大鼠脑组织凋亡与促凋亡蛋白表达水平的影响。方法采用双侧颈总动脉永久性结扎法建立慢性脑缺血大鼠模型,随机分为对照组、假手术组、模型组、EPO组。比较各组大鼠的神经功能评分,Morris水迷宫观察大鼠记忆能力,比较各组大鼠脑组织中超氧化物歧化酶(SOD)活性、丙二醛(MDA)、过氧化氢酶(CAT)活性以及谷胱甘肽(GSH)水平,苏木精-伊红(HE)染色法观察脑组织细胞形态,末端脱氧核苷酸转移酶介导的dUTP缺口末端标记测定(TUNEL)检测脑组织细胞凋亡率,蛋白免疫印迹法(Western-blot)检测脑组织中凋亡相关蛋白表达水平。结果与假手术组相比,模型组大鼠神经功能评分、细胞凋亡率、Caspase-3、Bax、Omi/HtrA2蛋白水平均升高(P<0.05),逃避潜伏期延长(P<0.05),穿越平台次数减少(P<0.05),SOD、CAT、GSH及Bcl-2蛋白水平降低(P<0.05),MDA含量升高(P<0.05);与模型组相比,EPO组神经功能评分、细胞凋亡率、MDA含量及Caspase-3、Bax、Omi/HtrA2蛋白水平降低(P<0.05),逃避潜伏期缩短(P<0.05),穿越平台次数增加(P<0.05),SOD、CAT、GSH活性及Bcl-2蛋白水平升高(P<0.05)。结论EPO对慢性脑缺血大鼠的脑组织损伤有保护作用,可能与其能够增强抗氧化能力、抑制脑组织细胞凋亡有关。

Objective To explore the effects of erythropoietin(EPO)on expression level of apoptotic and proapoptotic protein Omi/HtrA2 in brain tissue of rats with chronic cerebral ischemia.Methods The chronic cerebral ischemia rat models were established by permanent ligation method of bilateral common carotid arteries.The rats were randomly divided into control group,sham operation group,model group,and EPO group.The nerve function scores were compared among all groups.Morris water maze was performed to observe memory ability of rats.The levels of superoxide dismutase(SOD),malondialdehyde(MDA),catalase(CAT),and glutathione(GSH)in brain tissue were compared.Hematoxylin-eosin staining was performed to observe morphology of brain tissue.Apoptosis rate of brain tissue was detected by terminal-deoxynucleoitidyl transferase mediated nick end labeling method.The expression levels of apoptosis-related proteins in brain tissue were detected by Western-Blot.Results Compared with sham operation group,nerve function score,apoptosis rate,levels of Caspase-3,Bax,and Omi/HtrA2 protein were increased,escape latency was prolonged,while the number of running across the platform was decreased in model group,the levels of SOD,CAT,GSH,and Bcl-2 protein were decreased,while MDA content was increased in model group(P<0.05).Compared with model group,nerve function score,apoptosis rate,MDA content,levels of Caspase-3,Bax,and Omi/HtrA2 protein were decreased,escape latency was shortened,number of running across the platform was increased,levels of SOD,CAT,GSH,and Bcl-2 protein were increased in EPO group(P<0.05).Conclusion EPO has a protective effect on brain tissue injury in rats with chronic cerebral ischemia,which may be related to enhancing anti-oxidation ability and inhibiting apoptosis of brain tissue.