异丙酚联合电休克对抑郁大鼠海马卡配因Ⅰ-细胞周期依赖性蛋白激酶5通路的影响

摘要

Objective To investigate the effects of propofol combined with electroconvulsive therapy on calpain I/cyclin-dependent kinase 5 (Cdk5) pathway in the hippocampus of depressed rats. Methods Fifty Sprague-Dawley rats were randomly divided into 5 groups (n=10 per group): control group,depression group,propofol group,ECT group and propofol+ECT group. Depressed model was induced by chronic unpredictable mild stress procedure. Then rats in depression and propofol groups received intrapertioneal injection of saline (NS) and propofol,respectively. Rats in ECT group received ECT once a day for one week and rats in propofol+ECT group received ECT plus intraperitoneal injection of propofol once a day for one week. Open-field test was used to assess depressive status. Morris water maze was used to assess learning memory. The calpain I and Cdk5 protein and mRNA expressions were detected using immunohistochemistry,western-blot and RT-PCR,respectively. The Cdk5 activity was analyzed using a liquid scintillation counter. Results After treatment,the open-field scores in ECT group and propofol+ECT group were higher than those in either depression group or propofol group (P<0.05); the escape latency was longer and space exploration time was shorter in ECT group compared with either depression group or propofol group or propofol+ECT group (P<0.05); The expression levels of calpain I and Cdk5 protein and mRNA and the activity of Cdk5 in ECT group were higher than those in either depression group or propofol group (P<0.05),the expression levels of Cdk5 protein and mRNA and the activity of Cdk5 in propofol+ECT group were higher than those in either depression group or propofol group (P<0.05),but the expression levels of Cdk5 protein and mRNA in propofol+ECT group are lower than those in ECT group [calpain I protein in CA1 area: (0.15±0.03) vs. (0.20+0.03),calpain I protein in CA3 area: (0.17±0.03) vs. (0.22±0.03),calpain I mRNA : (0.58±0.02) vs. (0.82±0.05),Cdk5 protein: (0.76±0.05) vs. (1.13±0.05),Cdk5 mRNA: (0.46±0.01) vs. (0.63±0.03),the activity of Cdk5 (3272.92± 137.57) vs. (5770.24± 202.26) ] (P<0.05).Conclusions Propofol may alleviate ECT-induced learning memory impairment in depressed rats through decreasing the expression levels of calpain I-Cdk5 pathway in the hippocampus.%目的 观察异丙酚联合电休克对抑郁大鼠海马卡配因Ⅰ(calpain Ⅰ)-细胞周期依赖性蛋白激酶5(cyclin-dependent kinase 5,Cdk5)通路的影响.方法 SD大鼠50只随机分为抑郁模型组、异丙酚组、电休克组、异丙酚联合电休克组(简称联合组)和正常对照组各10只,前4组采用慢性轻度不可预见性应激建立抑郁模型.此后,抑郁模型组仅给予生理盐水,异丙酚组仅腹腔注射异丙酚,电休克组给予生理盐水加电刺激,联合组给予异丙酚加电刺激,对照组仅给予生理盐水,连续7d.采用open-field法评价抑郁状态,Morrs水迷宫检测学习记忆功能,免疫组织化学法检测海马CA1区和CA3区calpain Ⅰ的表达,western blot法和液闪法分别检测海马Cdk5的表达和活性,RT-PCR法检测calpain Ⅰ及Cdk5 mRNA的表达.结果 治疗后,电休克组和联合组的open-field评分高于抑郁模型组和异丙酚组,差异有统计学意义(P＜0.05)；电休克组的逃避潜伏期比抑郁模型组、异丙酚组和联合组延长而空间探索时间缩短(P＜0.05)；电休克组的calpain Ⅰ和Cdk5的蛋白及mRNA表达与Cdk5的活性均高于抑郁模型组、异丙酚组(P＜0.05),联合组的Cdk5蛋白及mRNA表达高于抑郁模型组和异丙酚组(P＜0.05),而联合组较电休克组的表达减少[CA1区calpain Ⅰ蛋白:(0.15±0.03)vs.(0.20±0.03),CA3区calpain Ⅰ蛋白:(0.17±0.03)vs.(0.22±0.03),calpain Ⅰ mRNA:(0.58±0.02)vs.(0.82±0.05),Cdk5蛋白:(0.76±0.05)vs.(1.13±0.05),Cdk5 mRNA:(0.46±0.01)w.(0.63±0.03),Cdk5活性:(3272.92±137.57)vs.(5770.24±202.26)].结论 异丙酚减轻抑郁大鼠电休克处理后学习记忆损害,其机制可能与异丙酚降低了电休克处理后calpain Ⅰ-Cdk5通路的表达有关.