一次性力竭运动对HIF-1α转基因鼠骨骼肌Nrf2抗氧化信号的影响

    Effects of Acute Exhaustive Exercise on the Antioxidant Signal of Nrf2 in Skeletal Muscle of HIF-1α Transgenic Mice

    • 摘要: 目的:探讨一次性力竭运动对HIF-1α转基因鼠骨骼肌Nrf2抗氧化信号的影响。方法:HIF-1α转基因鼠和野生型C57BL/6J小鼠各20只。随机分为野生安静组 (WC组) 、野生运动组 (WE组) 、转基因安静组 (HC组) 和转基因运动组 (HE组) 。正式实验时运动组小鼠做递增负荷跑台运动直至力竭, 运动后即刻取材, 脱颈处死后取两侧小腿骨骼肌。采用酶联免疫法 (ELISA) 测定骨骼肌Nrf2-ARE结合活性, 实时荧光定量PCR测定骨骼肌Nrf2下游抗氧化基因表达, Western Blot法测定骨骼肌中蛋白表达, 高质荧光测定法测定小鼠骨骼肌ROS。结果:1) 与WC组相比, HC组小鼠骨骼肌Nrf2 mRNA和蛋白表达显著增加, Nrf2-ARE结合活性显著增加, 靶基因SOD1、SOD2、NQO-1 mRNA表达显著增加, NQO-1蛋白表达显著增加, 骨骼肌ROS水平极显著下降;2) 与HC组相比, HE组小鼠骨骼肌核蛋白Nrf2含量显著性增加, SOD2和NQO-1 mRNA表达量显著增加, 且NQO-1蛋白表达显著增加, ROS无明显变化;3) 与WE组相比, HE组小鼠Nrf2 mRNA和蛋白表达显著增加, Nrf2核蛋白及P-Nrf2表达增加。骨骼肌SOD2和NQO-1 mRNA表达增加, NQO-1蛋白表达显著增加, 骨骼肌ROS含量极显著下降。结论:适当的HIF-1α高表达可提高安静状态下小鼠骨骼肌Nrf2-ARE通路的激活, 且对一次力竭运动后骨骼肌ROS的消除也有积极的调节作用。

       

      Abstract: To examine the effect of HIF-1α on Nrf2-ARE antioxidant pathway in mice skeletal muscle after acute exhaustion exercise. Methods: HIF-1α high expression (H) and C57 BL/6 J mice (W) were used at 20 respectively and each kind of mice were randomly divided into two groups: control (C) and exercise (E) . The treadmill exercise was preformed at the acute exhaustion exercise. On the day of acute exercise, mice allocated to perform treadmill running were subject to 5% incline and 5 min at 10 m/min, and then increased 3 m/min every 3 minutes. Mice were sacrificed at the indicated time points following treadmill running.Nrf2, phosphor-Nrf2 (Ser40) , nuclear Nrf2 protein were measured by Western Blot and Nrf2-ARE binding activity, the mRNA and proetin levels of Nrf2 target genes, key antioxidant enzymes (SOD1, SOD2, CAT, NQO-1) and ROS level, were also measured in skeletal muscles after the interventions. Results: 1) The results showed that compared with WC, RNA and protein expression level of Nrf2 were increased in HC skeletal muscles. Nrf2-ARE binding activity, Nrf2 target gene SOD1, SOD2, NQO-1 m RNA expression and NQO-1 protein expression were also increased in HC skeletal muscles. Meanwhile, ROS level in HC skeletal muscles decreased significantly. 2) After the acute exhaustion exercise, high HIF-1α expression mice (HE) had higher expression of p-Nrf2 (Ser40) and nuclear Nrf2 protein than the wide type mice (WE) . The m RNA expression of SOD1 and m RNA/protein of NQO-1 in HE increased as well. In contrast, ROS level decreased significantly in HE muscles. Conclusion: The result indicated that the proper high expression of HIF-1α could promote the antioxidant capacity of skeletal muscle in mice through Nrf2-ARE pathway.

       

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