Yongtian Huang*, Fanghui Li**, #
*Yichun Universtiy Sports College, Yichun, Jiangxi, China - **Pingxiang Universtiy Sports College, Pingxiang, Jiangxi, China
Objective: The purpose of this study was to investigate the role and mechanism of Nrf2 in regulating line intracellular free Ca2+([Ca2+]i) in C2C12 cell of mouse' skeletal muscle.
Methods: C2C12 cells were cultivated in vitro, and intervened by Nrf2 agonist t-BHQ and inhibitor Brusatol, and divided into blank control group (C), agonist group (S) and inhibitor group (I). The level of ROS in C2C12 cells was detected by fluorescence colorimetric assay. The change of [Ca2+]i in C2C12 cells was measured by laser scanning confocal microscopy after Fluo-4 AM loaded on C2C12 cells. The expression ofNrf2, RyR1, SERCA1, SERCA2, FKBP12, CaM, CaMKn and PKA protein in C2C12 cells were detected by Western Blot.
Results: 1) Compared with group C, the ROS level of C2C12 cells in group I was significantly increased. 2) Compared with group C, the [Ca2+]i of the C2C12 cells in group I was significantly increased after 185.4 s under the stimulation of H2O2 oxidative stress, while the [Ca2+]i of group I was significantly decreased after 61.8 s. 3) Compared with group C, the protein expression of Nrf2 was significantly lower in group I (P < 0. 05),but no change in group S. 4) Compared with group C, the expressions of RyR/ FKBP12 and PKA of group I were significantly increased (P < 0. 05), SERCA1 and SERCA2 protein were significantly decreased (P <0. 05),while the expressions of group S did not change significantly.
Conclusion: 1) Nrf2 plays a protective role in the process of oxidative stress-induced skeletal muscle [Ca2+]i increase. 2) Nrf2 inhibition can increase the expression of RyR and PKA protein in C2C12 cells, enhance the release function of sarcoplasmic reticulum calcium, decrease the expression of SERCA protein, and reduce calcium recovery in sarcoplasmic reticulum.
C2C12 cells, Mechanism, Nrf2, Sarcoplasmic Reticulum Calcium Regulation.