一次有氧运动对诱导型HIF-1α转基因鼠骨骼肌ERRα/γ核蛋白表达的影响
Effects of An Acute Aerobic Exercise on ERRα/γ Protein Expression of Skeletal Muscles in Inducible HIF-1α Transgenic Mice

摘要：低氧诱导因子-1α（hypoxia inducible factor-1α，HIF-1α）为机体的氧感受器，而雌激素相关受体α（estrogen-related receptor α，ERRα）是体内能量代谢的重要调节因子。目的：试图通过诱导型HIF-1α转基因鼠，探讨一次有氧运动中HIF-1α对骨骼肌ERRα/γ核蛋白及其靶基因表达的影响。方法：阴性对照小鼠（N）和高（H）、低（L）不同HIF-1α蛋白表达量的诱导型HIF-1α转基因鼠各20只，随机又分为2组（安静组和1 h运动组），每组10只，共6组。运动组完成速度20 m/min，坡度5%，运动时间为1 h的一次性跑台运动。运动后3 h取材。Western blot测定ERRα/γ核蛋白表达。RT-PCR测定靶基因MCAD、PPARα、NRF1和PDK4 mRNA含量。结果：1）在安静状态下，L组小鼠与N组小鼠相比，PPARα 和MCAD mRNA表达量显著性增加，而H组小鼠与N组小鼠相比，骨骼肌ERRα核蛋白表达量显著性下降；2）1 h运动后，L组中的运动组与其安静组相比，骨骼肌ERRγ核蛋白表达量非常显著性增加，并且与N组中的运动组相比也显著性提高。然而，H组中的运动组与N组中的运动组相比则呈现显著性降低。结论：1）1 h运动促进L鼠骨骼肌ERRγ核蛋白表达增加；2）体内HIF-1α蛋白表达量适度增加，有利于安静状态和1 h运动后ERRα/γ核蛋白及其靶基因mRNA的表达，而HIF-1α蛋白的过度表达，则相反。
Abstract: HIF-1α (hypoxia inducible factor-1α) is an oxygen sensor, and EERα (estrogen-related receptor α) is an important regulator of energy metabolism. This study aimed at discussing the effect of HIF-1αon nucleoprotein ERRα, ERRγ and their target genes during acute exercise in inducible HIF-1α transgenic mice. Methods: Non-transgenic mice (N), HIF-1α low-expression transgenic mice (L) and HIF-1α high-expression transgenic mice (H) were divided into control group and 1 hour aerobic exercise group respectively (n=10, 6 groups in total). The exercise program is 20 m/min, 5o degree, 1 hour in total. Skeletal muscle was collected 3 hours after exercise. Nucleoprotein ERRα and ERRγ were tested by Western blotting and their target genes MCAD, PPARα, NRF1and PDK4 mRNA expression were tested by RT-PCR. Results: 1) The expressions of PPARα and MCAD were higher in L control group than in N control group, and the expression of ERRα/γ nucleoprotein of skeletal muscle was higher in H control group than in N control group. 2) After one hour aerobic exercise, compare with L control group, the expression of ERRγ nucleoprotein in L exercise group was significantly higher, also it was higher than that in N exercise group. But compared with H exercise group after exercise, the expression of ERRγ nucleoprotein was lower. Conclusions: 1) One hour exercise could promote ERRγ nucleoprotein expression of skeletal muscle in L and N mice; 2) Appropriate increase of HIF-1α protein is benefit to ERRα/γ nucleoprotein expression and the target gene mRNA expression at rest state and after 1 hour exercise, but if HIF-1α protein content is too much, vice versa