VDR and CYP27B1 are expressed in C2C12 cells and regenerating skeletal muscle: potential role in suppression of myoblast proliferation

作者：Srikuea Ratchakrit^*; Zhang Xiping; Park Sarge Ok Kyong; Esser Karyn A

来源：American Journal of Physiology - Cell Physiology, 2012, 303(4): C396-C405.

DOI：10.1152/ajpcell.00014.2012

• 1 alpha-hydroxylase
• 1 alpha,25(OH)(2)D-3
• 25(OH)D-3
• muscle regeneration
• vitamin D receptor

Srikuea R, Zhang X, Park-Sarge OK, Esser KA. VDR and CYP27B1 are expressed in C2C12 cells and regenerating skeletal muscle: potential role in suppression of myoblast proliferation. Am J Physiol Cell Physiol 303: C396-C405, 2012. First published June 6, 2012; doi:10.1152/ajpcell.00014.2012.-1 alpha,25(OH)(2)D-3, the active form of vitamin D-3, has been reported to regulate the cell biology of skeletal muscle. However, there has been some controversy about the expression of the vitamin D receptor (VDR) and thus the potential role of vitamin D3 in skeletal muscle. In this study, we isolated and sequenced the full-length Vdr and Cyp27b1 transcripts in C2C12 myoblasts and myotubes. Western blots and immunocytochemistry confirmed protein expression in both myoblasts and myotubes clearly demonstrating that C2C12 cells express VDR and CYP27B1. To determine the vitamin D-3 action, we found that C2C12 myoblasts treated with either 1 alpha,25(OH)(2)D-3 or 25(OH)D-3 inhibited cell proliferation and this was associated with increased Vdr expression. The observation that treatment of C2C12 myoblasts with the inactive form of vitamin D-3, [25(OH)D-3], inhibited proliferation suggested that CYP27B1 was functionally active. We used small interfering RNA to knock down Cyp27b1 in myoblasts, and cells were treated with 25(OH)D-3. The growth-suppressive effects of 25(OH)D-3 were abolished, suggesting that CYP27B1 in myoblasts is necessary for the ability of 25(OH)D-3 to affect cell proliferation. Finally, we analyzed expression of VDR and CYP27B1 in regenerating skeletal muscle in vivo. We found that expression of VDR and CYP27B1 increased significantly at day 7 of regeneration, and these results confirm the expression of Vdr and Cyp27b1 in vivo and suggest a potential role for vitamin D-3 in skeletal muscle regeneration following injury.

• 出版日期2012-8