Role of Rho small GTPases in meniscus cells
Version of Record online: 11 AUG 2014
© 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.
Journal of Orthopaedic Research
Volume 32, Issue 11, pages 1479–1486, November 2014
How to Cite
Kanazawa, T., Furumatsu, T., Matsumoto-Ogawa, E., Maehara, A. and Ozaki, T. (2014), Role of Rho small GTPases in meniscus cells. J. Orthop. Res., 32: 1479–1486. doi: 10.1002/jor.22703
- Issue online: 22 SEP 2014
- Version of Record online: 11 AUG 2014
- Manuscript Accepted: 1 JUL 2014
- Manuscript Received: 26 FEB 2014
- Dr. Aki Yoshida and Dr. Zhichao Lu for their technical assistance. This work was supported by Japan Society for the Promotion of Science (no. 24791546 to T.F.)
- Mechanical stretch;
We previously reported that mechanical stretch regulates Sry-type HMG box (SOX) 9-dependent α1(II) collagen (COL2A1) expression in inner meniscus cells. This study examined the role of the small Rho guanosine 5' triphosphatase Rac1 and Rho-associated kinase (ROCK) in the regulation of stretch-induced SOX9 gene expression in cultured human inner meniscus cells. COL2A1 and SOX9 gene expression was assessed by real-time PCR after application of uni-axial cyclic tensile strain (CTS) in the presence or absence of ROCK and Rac1 inhibitors. The subcellular localization of SOX9 and the Rac1 effector cyclic AMP response element-binding protein (CREB), the phosphorylation state of SOX9, Rac1 activation, and the binding of CREB to the SOX9 promoter were assessed. CTS increased the expression of COL2A1 and SOX9, which was suppressed by inhibition of Rac1. ROCK inhibition enhanced COL2A1 and SOX9 gene expression in the absence of CTS. CTS stimulated the nuclear translocation and phosphorylation of SOX9, and increased Rac1 activation. CTS also increased the binding of CREB to the SOX9 promoter. The results suggest that mechanical stretch-dependent upregulation of SOX9 by CREB in inner meniscus cells depends on the antagonistic activities of ROCK and Rac1. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:1479–1486, 2014.