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目的:探讨急性有氧运动对大鼠海马组织PI3K/Akt/GSK3β信号通路的影响。方法:雄性SD大鼠随机分为安静对照组(CG)和急性运动组(EG)。EG组大鼠进行1 h急性有氧运动,跑台速度为25 m/min,相当于75%VO2max负荷强度。运动后即刻、12 h、24 h、36 h和48 h,分离海马组织,通过荧光定量PCR和Western blot检测PI3K催化亚基p110、Akt、GSK3β以及下游底物tau的mRNA和蛋白含量及其磷酸化水平。结果:急性有氧运动后EG组大鼠海马组织PI3K p110 mRNA和蛋白含量均呈现先上升后下降的趋势;12 h时mRNA含量达到最高,约是CG组的2.21倍(P<0.01);而24 h时其蛋白含量达到最高,约是CG组的1.45倍(P<0.05);至48 h时其mRNA和蛋白含量均下降至CG组水平。Akt和GSK3β的mRNA和总蛋白含量在48 h内与CG组相比无显著性变化;而Akt Ser473位和GSK3βSer9位的磷酸化水平在24 h时均达到最高峰,分别是CG组的5.98倍(P<0.01)和2.4倍(P<0.01);48 h时逐渐下降至CG组水平。下游底物tau的磷酸化水平却呈现先下降后上升的趋势,在24 h时其Ser202位磷酸化水平最低,约为CG组的60%(P<0.05)。结论:急性有氧运动能够在短期内提高大鼠海马组织PI3K p110 mRNA和蛋白含量,增强其激酶活性;提高Akt Ser473位磷酸化水平,激活Akt;活化的Akt使GSK3βSer9位磷酸化水平提高,抑制GSK3β的激酶活性;最终导致tau蛋白Ser202位的磷酸化水平降低。因此急性有氧运动能够在短期内提高大鼠海马组织PI3K/Akt/GSK3β信号通路活性。
Objective: To investigate the effects of acute aerobic exercise on the PI3K / Akt / GSK3β signaling pathway in hippocampus of rats. Methods: Male Sprague-Dawley rats were randomly divided into a quiet control group (CG) and an acute exercise group (EG). Rats in EG group were subjected to acute aerobic exercise for 1 hour and treadmill speed was 25 m / min, equivalent to 75% VO2max load intensity. The hippocampus tissues were isolated immediately after exercise, at 12 h, 24 h, 36 h and 48 h, and the mRNA and protein contents of the PI3K catalytic subunits p110, Akt, GSK3β and the downstream substrate tau were detected by real-time PCR and Western blot. Level Results: After acute aerobic exercise, the mRNA and protein levels of PI3K and p110 in hippocampus of rats increased firstly and then decreased, and reached the peak at 12 h, which was about 2.21 times that of CG group (P <0.01) At 24 h, the protein content reached the highest level, about 1.45 times that of CG group (P <0.05). At 48 h, the mRNA and protein levels decreased to CG level. Akt and GSK3β mRNA and total protein content within 48 h compared with the CG group had no significant change; while Akt Ser473 and GSK3βSer9 phosphorylation peak reached the peak at 24 h, respectively, 5.98 times the CG group (P <0.01) and 2.4 times (P <0.01), and gradually decreased to CG group at 48 hours. The phosphorylation level of downstream substrate tau initially decreased and then increased. The phosphorylation level of Ser202 was the lowest at 60 h, about 60% of CG group (P <0.05). CONCLUSION: Acute aerobic exercise can increase the mRNA and protein level of PI3K p110 in hippocampus of rats in a short term, enhance its kinase activity, raise the phosphorylation level of Akt Ser at position 4773, and activate Akt. Activation of Akt enhances phosphorylation of GSK3βSer9 and inhibits GSK3β kinase activity; eventually leading to tau protein Ser202 position phosphorylation decreased. Therefore, acute aerobic exercise can increase the PI3K / Akt / GSK3β signaling pathway activity in the hippocampus in a short time.