Exercise Training Promoted Antioxidative Protein Adaptation In Skeletal Muscle Via Nrf2 Signaling

The purpose of this study was to investigate the role of nuclear erythroid 2 p45-related factor 2(Nrf2)in antioxidative adaptation in skeletal muscle evoked by moderate intensity exercise training.Two-month-old wild-type mice(C67BL/6J)and Nrf2 knockout mice were divided into the exercise and control groups(n=8-10/group),separately.The exercise groups were trained on a treadmill six days per week,one hour per day for four weeks.Measurements of reactive oxygen species(ROS),4-hydroxy-2-nonenal(4-HNE)-modified proteins,Nrf2 target genes’ mRNA and protein expressions(superoxide dismutase(SOD),NAD(P)H quinoneoxydase-1(NQO-1),hemoxygenase-1(HO-1),γ-glutamyl cysteine ligase-catalytic(GCLc),glutathione peroxydase(GPX),glutathione reductase(GSR),and catalase(CAT))were carried out after four weeks of interventions.Compared to non-exercise control wild-type mice,non-exercise control Nrf2 knockout mice did not show significant changes in ROS,and five antioxidant proteins(CAT,NQO1-1,GCLc,HO-1,and SOD2)in skeletal muscle.After four weeks of exercise,the trained Nrf2 knockout mice presented significantly lower ROS and the expressions of antioxidant proteins than those of the trained wild-type mice.These results suggested that Nrf2 played a crucial role in this adaptive process induced by moderate intensity exercise training.