螺旋藻营养补充通过MEK/ERK信号途径改善运动疲劳大鼠海马损伤

PROTECTIVE EFFECTS OF SPIRULINA ON EXERCISE-INDUCED HIPPOCAMPAL INJURY FOR FATIGUE RATS VIA REGULATING MEK/ERK SIGNAL PATHWAY

目的探讨螺旋藻(SP)营养补充对MEK/ERK信号通路活性的调控及其在运动疲劳大鼠海马损伤中的作用。方法90只清洁级健康SD大鼠随机分为正常对照组(NC组)、运动模型组(EM组)、运动+SP组(ES组)、运动+MEK阻滞剂组(EPD组)、运动+SP+MEK阻滞剂组(ESPD组)、阳性对照组(PC组),共6组,每组均为15只。实验末,用免疫组化和免疫印迹法检测各组大鼠海马p-MEK、p-ERK和Actived Caspase-3蛋白的表达含量,生化法观察血清BUN和BLA含量的变化,同时行尼氏染色法观察海马神经元的病理形态学改变。结果(1)与NC组相比,其余组海马CA1区细胞结构呈不同程度的病理改变;与EM组、EPD组、ESPD相比,ES组损伤程度要轻,其细胞整体形态渐趋于PC组;ESPD组细胞整体形态要好于EM组,EM组要好于EPD组。(2)ES组血清BUN和BLA含量均显著低于EM组,且较PC组无明显区别。(3)ES组海马p-MEK和p-ERK表达均显著高于EM组、ESPD和EPD组,但显著低于PC组;而Actived Caspase-3表达则相反,显著低于EM组、EPD组和ESPD组,但稍高于PC组,两者无明显差别。结论螺旋藻营养补充能降低运动疲劳大鼠血清BUN和BLA含量,减轻海马形态损伤;其原因可能与其上调MEK和ERK的磷酸化水平和抑制Caspase-3活化而抑制细胞凋亡的神经保护作用有关。

Objective:To investigate the protective effects of spirulina(SP)on exercise-induced hippocampal injury for fatigue mice via regulating MEK/ERK signaling pathway.Methods:SD rats were randomly divided into six groups:normal control group(NC),high intensity exercise model group(EM),`exercise plus spirulina group(ES),exercise plus PD98059 group(EPD),exercise plus spirulina plus PD98059 group(ESPD),and positive control group(PC),15 rats each group.At the end of the experiment,p-MEK,p-ERK and Actived Caspase-3 expression content were detected by immune-histochemistry and western blot analysis,serum BUN and BLA content were observed by biochemical methods,and micromorphological changes in hippocampal CA1 were detected by Nissl staining.Results:Compared with NC group,other groups displayed abnormal phenomenons;Compared with EM,EPD and ESPD group,the damage degree of the cell structure of ES group with SP treatment was milden,and was closer to PC group;the cell structure of ESPD group was better than that of EM group,and the cell structure of EM group was better than that of EPD group.Compared with EM group,serum BUN and BLA content in ES group decreased significantly,and there was no difference compared to PC group.p-MEK and p-ERK protein expressions in ES group were significantly higher than that of EM,ESPD and EPD group,but were lower than that of PC group;while Actived Caspase-3 expression decreased obviously compared to EM,ESPD and EPD group,but was slightly higher than that of PC group.Conclusions:SP could reduce serum BUN and BLA content,and improve hippocampus morpholohy injury.Its mechanism was related to SP further increased p-MEK and p-ERK expression,and reduced Actived Caspase-3 expression to inhibit cell apoptosis in the exercise rats.