米诺环素与海湾战争综合征大鼠海马神经细胞凋亡关系研究

Correlation between minocycline and hippocampal neuronal apoptosis in rat models of Gulf War syndrome

目的探讨米诺环素抗凋亡的Caspase-3依赖性信号途径与海湾战争综合征(GWS)大鼠海马CA1区神经细胞凋亡的关系。方法健康雄性Wistar大鼠24只,随机分为对照组、束缚应激组、GWS模型组与米诺环素组,每组各6只。束缚应激组大鼠每天置于狭小的、完全避光的容器中束缚20 min。GWS模型组建立GWS大鼠模型,每天置于狭小的、完全避光的容器中束缚20 min,溴化吡啶斯的明1.3 mg/(kg·d)口服,二乙基甲苯甲酰胺40 mg/(kg·d)以70%乙醇皮下注射。米诺环素组在GWS模型组的基础上,腹腔注射米诺环素45 mg/(kg·d)。对照组每天以等量70%乙醇溶液皮下注射。28 d结束后,处死动物,取脑。采用TUNEL法原位检测海马CA1区神经细胞凋亡情况;采用免疫组化方法检测Caspase-3、Apaf-1、Smac与Omi/Htr A2蛋白的表达情况。结果束缚应激组与对照组比较,海马CA1区神经细胞凋亡数量、Caspase-3、Apaf-1、Smac及Omi/Htr A2表达差异无统计学意义(P>0.05)。GWS模型组与对照组比较,海马区TUNEL阳性细胞数量增多,Caspase-3、Apaf-1、Smac及Omi/Htr A2蛋白表达增加,差异有统计学意义(P<0.01)。米诺环素组与GWS模型组比较,海马区TUNEL阳性细胞数减少,Caspase-3、Smac表达减少,差异有统计学意义(P<0.01);Apaf-1、Htr A2蛋白表达无明显变化,差异无统计学意义(P>0.05)。结论米诺环素通过下调Smac与Caspase-3的表达,对GWS大鼠海马神经细胞起保护作用。

Objective To investigate the neuroprotective effect of minocycline on the neuronal apoptosis and the Caspase-3 dependant pathway in the hippocampal CA1 region in rat models of Gulf War syndrome（ GWS）. Methods A total of 24 healthy male Wistar rats were established modeling. The modeling rats were randomly divided into the control group,restraint-stress group,GWS group and minocycline group. Rats in the restraint-stress group were restraint-stressed in narrow and completely avoid light container for 20 minutes every day. GWS rat models were established in the GWS group,rats were restraint-stressed in narrow and completely avoid light container for 20 minutes and received hypodermic injection in a dose of 70% ethanol solution and oral PB 1. 3 mg/（ kg·day）,DEET40 mg/（ kg·day）. Rats in minocycline group were based on GWS group,received intraperitoneal injection of minocycline in dose of45 mg/（ kg·d）. Rats in the control group received subcutaneous injection of equivalent 70% ethanol solution every day. The rats were killed at the end of the 28 days-experiment,and the brains were removed to detect the neuronal apoptosis in the hippocampal CA1 region by TUNEL method and the expression of Caspase-3,Apaf-1,Smac and Omi/Htr A2 using immunohistochemical staining.Results There was no significant difference in neuronal apoptosis counting,Caspase-3,Apaf-1,Omi/Htr A2 and Smac expressions in hippocampal CA1 area between the restraint-stress group and the control group（ P〈0. 05）. The number of neuronal apoptosis and the expression of Caspase-3,Apaf-1,Smac and Omi/Htr A2 proteins in the hippocampal CA1 region increased in the GWS group compared with the control group（ P〈0. 01）. In the minocycline groups,the number of neuronal apoptosis and the expressions of Caspase-3 and Smac in hippocampal CA1 area reduced significantly compared to the GWS model group（ P〈0. 01）;there was no change of Apaf-1and Omi/Htr A2 expression（ P〈0. 05）. Conclusion Minocycline could protect against the apoptosis of the hippocampal CA1 neurons in rat models of gulf war syndrome by down-regulating the Smac and Caspase-3 expression.