低氧运动对Nrf2基因敲除大鼠运动能力和氧化应激的影响

Nrf2可调节多种抗氧化酶的表达,Nrf2的缺失可能影响机体的运动能力,而低氧可提高机体的抗氧化能力并改善运动能力。为了考察低氧运动对Nrf2基因敲除大鼠运动能力和氧化应激的影响,本研究分别在常氧和低氧环境(12%氧浓度)中对野生型大鼠和Nrf2敲除大鼠进行4周的跑台运动。研究显示,低氧运动可提高野生型大鼠的跑台运动力竭时间,Nrf2敲除可缩短大鼠的力竭时间;低氧运动可上调大鼠的Nrf2 m RNA表达量;Nrf2敲除明显抑制HIF-1α蛋白表达,而低氧运动可上调野生型和Nrf2敲除大鼠的HIF-1α蛋白表达;Nrf2敲除大鼠的骨骼肌ROS水平明显升高,并且低氧均可降低野生型和Nrf2敲除大鼠骨骼肌ROS水平。低氧运动可上调Nrf2敲除大鼠的CAT和GSH-PX蛋白表达。苏木精和伊红(HE)染色显示,Nrf2敲除大鼠在力竭跑台运动完成后出现更严重的骨骼肌病理改变,而低氧运动可减轻骨骼肌损伤。本研究认为,Nrf2敲除导致了大鼠骨骼肌中抗氧化酶的抑制及ROS的过量累积,从而造成了骨骼肌损伤并降低了运动能力。此外,低氧可通过上调Nrf2的表达,进而激活HIF-1α及抗氧化酶活性,从而提高运动能力,并防止骨骼肌损伤。

Effects of Hypoxic Exercise on Exercise Capacity and Oxidative Stress in Nrf2 Knockout Rats

Nrf2 can regulate the expression of various antioxidant enzymes.The loss of Nrf2 may affect the body’s ability to exercise,and hypoxia can improve the body’s antioxidant capacity and improve exercise capacity.The aim of this study was to investigate the effects of hypoxic exercise on exercise capacity and oxidative stress in Nrf2 knockout rats.In this study,wild-type rats and Nrf2 knockout rats were subjected to treadmill exercise for 4 weeks in normoxia or hypoxia(12% oxygen concentration).Studies showed that hypoxic exercise increased the running time of treadmill exercise in wild-type rats.Nrf2 knockout shortened the exhaustion time of rats.Hypoxic exercise up-regulated the expression of Nrf2 mRNA in rats.Nrf2 knockout significantly inhibited HIF-1α protein expression.Hypoxia exercise up-regulated HIF-1α protein expression in wild-type and Nrf2 knockout rats.Skeletal muscle ROS levels were significantly elevated in Nrf2 knockout rats.And hypoxia reduced skeletal muscle ROS levels in wild-type and Nrf2 knockout rats.Hypoxic exercise up-regulated CAT and GSH-PX protein expression in Nrf2 knockout rats.Hematoxylin and eosin(HE) staining showed that Nrf2 knockout rats showed more severe skeletal muscle pathological changes after exhaustive treadmill exercise,while hypoxic exercise reduced skeletal muscle damage.This study suggest that Nrf2 knockout lead to inhibition of antioxidant enzymes and excessive accumulation of ROS in rat skeletal muscle,resulting in skeletal muscle damage and reduced exercise capacity.In addition,hypoxia could up-regulate the expression of Nrf2,thereby activat HIF-1α and antioxidant enzyme activities,thereby improve exercise capacity and preventing skeletal muscle damage.