The Effects of Endurance Training on the Regulation of Sarcoplasmic Reticulum Calcium in Nrf2 Knockout Mice

Objective:To investigate the effects of eight weeks endurance training on the regulation of sarcoplasmic reticulum calcium in Nrf2 knockout mice.Methods:Eight weeks Nrf2 knock out(KO)mice and wild mice were randomly assigned to a sedentary control group and an exercise training group(n=10):wild control group(WC),wild exercise group(WE),KO control group(KC)and KO exercise group(KE).Mice in exercise groups underwent 60min/day treadmill running at speed of 12m/min for eight weeks.Skeletal muscle was collected 48 hours after training.The concentration of Ca~(2+)(Ca~(2+))was tested by MTB.The protein expressions of Nrf2,RyR,FKBP12,CaM and SERCA in skeletal muscle were analyzed by Western Blot.Results:1)Campared with WC,the expression of RyR,FKBP12 and CaM in KC were significantly increased(P<0.05);while after eight weeks training decreased the expression of CaM in KE than KC(P<0.05);2)SERCA1in KC was decreased than WC(P<0.05),while SERCA1 was increased in KE than KC;3)There is no difference ofCa~(2+)among groups.Conclusion:1)The expression of RyR and CaM were compensatory increased in Nrf2 KO mice;The expression of SERCA1 was decreased in Nrf2 KO mice,inducing the capacity of recruiting Ca~(2+)in sarcoplasmic reticulum was decreased;2)Eight weeks endurance training increased the capacity of sarcoplasmic reticulum Ca~(2+)release by increasing the expression of RyR in wild mice,while by weakening the inhibition of CaM in Nrf2 KO mice.Eight weeks endurance training can repair the decline of the capacity of recruiting Ca~(2+)in Nrf2 KO mice sarcoplasmic reticulum.