海马缝隙连接蛋白43与卒中后抑郁的关系研究

Relationship between hippocampal connexin 43 and post-stroke depression

目的探讨海马组织缝隙连接蛋白43(Cx43)与卒中后抑郁(PSD)的抑郁症状的相关性。方法42只大鼠随机均分为正常组、卒中组、抑郁组、PSD组、生理盐水组、缝隙连接抑制剂(CBX)组和缝隙连接激动剂(ATRA)组,每组6只。采用脑立体定位仪定位微量注射内皮素-1制备脑缺血模型;采用慢性不可预见的温和应急刺激(CUMS)结合孤养法制备抑郁模型;建立脑缺血模型后,加以CUMS和孤养法制备PSD模型;在PSD组术后14d,将大鼠随机分为PSD组、生理盐水组、ATRA组和CBX组,每组6只。PSD组继续进行PSD造模,不做其他干预。其余3组在继续PSD造模的同时予以以下干预:生理盐水组每日予生理盐水1ml腹腔内注射;ATRA干预组每日予1ml ATRA(浓度为1mg/ml)腹腔内注射;CBX干预组,每日予CBX,20mg/kg的标准腹腔注射,连续给药14d。术后28d,用Real time PCR和Western blot和免疫荧光染色检测大鼠海马Cx43 mRNA及其蛋白表达。结果术后28d,与正常组相比,抑郁组和PSD组大鼠的体重和旷场实验中的穿越总距离显著减少(P<0.05);海马的Cx43 mRNA和蛋白表达水平明显降低(P<0.05)。经过CBX干预后,PSD组大鼠的体重和旷场实验中的穿越总距离进一步减少(P<0.05);海马Cx43 mRNA蛋白的表达进一步降低(P<0.05)。经过ATRA干预后,PSD组大鼠的体重和旷场实验中的穿越总距离增加(P<0.05);海马Cx43 mRNA和蛋白的表达有所升高(P<0.05),但仍低于正常组(P<0.05)。结论PSD大鼠海马Cx43表达下降可能在PSD发病过程中发挥着一定的作用。

Objective To investigate the relationship between hippocampal connexin 43(Cx43)and symptoms of post-stroke depression(PSD).Methods 42rats were randomly divided into the normal group,the stroke group,the depression group,the PSD group,the normal saline group,the CBX(carbenoxolone,agap junction inhibitor)group and the ATRA(the gap junction agonist)group,with 6rats in each group.The model of cerebral ischemia was established by micro-injection of endothelin-1under the positioning of a brain stereotactic instrument.The depression model was established by method of chronic unpredictable mild emergency stimulation(CUMS)combined with solitary rearing.Based on the the cerebral ischemia model,the PSD model was prepared by CUMS and solitary rearing.On the 14th day after operation,the rats in PSD group were randomly divided into the PSD group,the normal saline group,ATRA group and CBX group,with 6rats in each group.The PSD group continued to be modelled by PSD without other intervention.The other three groups received the following interventions while being modelled by PSD:the normal saline group was injected intraperitoneally with 1ml normal saline every day;the ATRA group was injected intraperitoneally with 1ml of ATRA(concentration:1mg/ml)every day for 14days;the CBX group was given 20mg/kg of CBX by means of standard intraperitoneal injection each day for 14days.At twenty-eight days after operation,the expressions of Cx43 mRNA and protein in rat hippocampus were detected by real time PCR and Western blot and immunoflu orescent staining.Results At day 28after operation,compared with the normal group,the depression group and PSD group had significant reduced weight and total crossing distance in open field experiment of rats(P<0.05).Their expression levels of Cx43 mRNA and protein in hippocampus decreased significantly(P<0.05).After CBX intervention,in the PSD group,the rats’body weight and total crossing distance in open field experiment further reduced(P<0.05),and the expressions of Cx43 mRNA protein in hippocampus further decreased(P<0.05).After ATRA intervention,there was an increase in the body weight and total crossing distance in open field experiment of rats in PSD group(P<0.05),and there was a certain increase in their expressions of Cx43 mRNA and protein in hippocampus(P<0.05),but these expressions were still lower than those of the normal group(P<0.05).Conclusion The decreased expression of Cx43in hippocampus of PSD rats may play a role in the pathogenesis of PSD.