8w有氧运动调控成年大鼠皮层Rho GTPases活性

The effects of 8 weeks aerobic exercise on the activity of Rho GTPases in rat cortex

目的观察8 w有氧运动对成年大鼠皮层Rho GTPases的影响。方法 (1)选用30只3月龄、雄性、Wistar大鼠,经过1 w的适应性跑台训练后,随机分为安静对照组和有氧运动组,每组15只。运动组大鼠进行8 w跑台运动,前2 w运动速度为10 m/min,跑台坡度为5%,每天运动30 min;后6 w运动速度为22 m/min,跑台坡度为10%,每天运动60 min;最后一次运动训练48 h后取材。(2)采用Western印迹方法检测两组大鼠皮层RhoA、Rac1和Cdc42蛋白表达。(3)采用Real Time PCR方法检测两组大鼠皮层RhoA、Rac1和Cdc42 mRNA表达。(4)采用突触素作为突触特异性的标记物,应用免疫组织化学法和免疫荧光技术检测两组大鼠皮层的突触密度。结果 (1)同安静对照组相比,有氧运动组大鼠皮层内RhoA蛋白表达下调、RhoA mRNA表达上调(P<0.01);Rac1蛋白、Rac1 mRNA、Cdc42蛋白表达上调,Cdc42 mRNA表达下调(P<0.01或P<0.001)。(2)同安静对照组相比,有氧运动组大鼠皮层的突触密度增多(P<0.05)。结论 8 w有氧运动对成年大鼠大脑皮层参与细胞骨架调节的Rho GTPases具有调控作用,抑制RhoA表达,促进Rac1和Cdc42表达,进而增加成年大鼠大脑皮层内的突触密度。

Objective To investigate the effects of 8 weeks aerobic exercise on the activity of Rho GTPases in the rat cortex.Methods 3 months old male Wistar rats were randomly divided into sedentary and treadmill exercise groups after the familiarization to treadmill exercise for 5 d,then ran 30 min/d at 10 m/min on a 5％ slope for the first 2 w.The running speed and duration of the exercises were gradually increased,up to 60 min/d at 22 m/min on a 10％ slope for 6 w.All rats were killed 48 h after the last exercise session.The protein levels of RhoA,Rac1 and Cdc42 were detected by Western blotting and the mRNA levels with Real Time PCR.Furthermore,the levels of synaptophysin in the cortex and hippocampus separately were measured by ICH and IF method,which had been widely used to assess synapse density.Results The protein level of RhoA was decreased and mRNA level was increased in cortex compared with those in control groups.The protein levels of Rac1 and mRNA level of Rac1 were increased in cortex compared with those in control groups,and the protein level of Cdc42 was increased,but the mRNA level of Cdc42 was decreased in cortex compared with those in sedentary groups.The synapse density was increased of in cortex after 8 w aerobic exercise.Conclusions Rho GTPase is regulated by 8 w treadmill exercise in rat cortex,and the expression of RhoA is inhibited,the expressions of Rac1 and Cdc42 are increased,which might be an important molecular mechanism of exercise-induced neurogenesis including increasing synapse density in the cortex.