核因子E2相关因子2基因在低氧运动下的表达及其对机体抗氧化能力的调节作用

核因子E2相关因子2 (nuclear factor E2 related factor 2,Nrf2)基因可调节多种抗氧化酶活性并间接影响抗疲劳和抗氧化能力,而低氧环境有助于运动能力的提升。为了考察低氧运动对Nrf2基因敲除小鼠的抗疲劳和抗氧化能力的影响,本研究将敲除Nrf2基因的小鼠置于模拟海拔3 000 m和5 000 m (氧浓度约为14.4%和11.1%)的环境中进行4周的低氧训练。研究发现,模拟海拔3 000 m的低氧运动显著提高了小鼠的力竭跑台运动时间,并减弱了骨骼肌损伤。而模拟海拔5 000 m的低氧运动未出现上述效果。低氧运动显著上调了Nrf2 mRNA表达以及HIF-1α、SOD1、SOD2、GR、GSH-PX、NQO-1和HO-1蛋白表达。模拟海拔3 000 m的低氧运动降低了机体ROS和MDA水平,而模拟海拔5 000 m的低氧运动提高了机体ROS和MDA水平。本研究表明敲除Nrf2抑制了小鼠体内抗氧化酶活性,并降低了小鼠的身体机能。而适当的低氧运动则可通过上调Nrf2和HIF-1α的表达来间接提高抗氧化酶活性,改善机体的氧化-还原状态,从而提高抗疲劳和抗氧化能力。然而,氧浓度过低则会产生相反的效果。

Expression of Nuclear Factor E2-related Factor-2 Gene in Hypoxia Exercise and Its Regulating Effect on Antioxidant Capacity

The Nuclear factor E2-related factor 2(Nrf2) gene can regulate a variety of antioxidant enzyme activities and indirectly affect the anti-fatigue and anti-oxidation ability,while the hypoxic environment contributes to the improvement of exercise capacity.To investigate the effects of hypoxic exercise on the anti-fatigue and antioxidative capacity of Nrf2 knockout mice,Nrf2 knockout mice were placed in simulated environments with altitudes of 3 000 m or 5 000 m(oxygen concentrations of approximately 14.4% and 11.1%).Four weeks of hypoxic training was performed.The study found that simulated hypoxia exercise at an altitude of 3 000 m significantly increased the exhausted running time of the mice and reduced the skeletal muscle damage.The hypoxic exercise with a simulated altitude of 5 000 m did not show the above effect.Hypoxia exercise significantly up-regulated Nrf2 mRNA expression and HIF-1α,SOD1,SOD2,GR,GSH-PX,NQO-1 and HO-1 protein expression.Simulated hypoxic exercise at an altitude of 3 000 m reduced ROS and MDA content,while simulated hypoxia exercise at an altitude of 5 000 m increased ROS and MDA content.This study demonstrates that Nrf2 knockdown inhibits antioxidant enzyme activity and reduces the body’s function in mice.Appropriate hypoxic exercise can increase the activity of antioxidant enzymes and improve the oxidation-reduction state of the body by up-regulating the expression of Nrf2 and HIF-1α,thereby improving the anti-fatigue and anti-oxidation ability.However,low oxygen concentration will have the opposite effect.