This Article Figures Only Free Full Text Free Free Full Text (Free PDF) Free Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Tanaka, N. Articles by Tanne, K. Search for Related Content PubMed PubMed Citation Articles by Tanaka, N. Articles by Tanne, K. Social Bookmarking                         What's this?

Cyclic Mechanical Strain Regulates the PTHrP Expression in Cultured Chondrocytes via Activation of the Ca²⁺ Channel

N. Tanaka^1,, S. Ohno^1,*,, K. Honda¹, K. Tanimoto¹, T. Doi¹, M. Ohno-Nakahara¹, E. Tafolla², S. Kapila³ and K. Tanne¹

¹ Departments of Orthodontics and Craniofacial Developmental Biology, Hiroshima University Graduate School of Biomedical Sciences, 1-2-3 Kasumi, Minami-Ku, Hiroshima 734-8553, Japan;
² Department of Stomatology, University of California-San Francisco, San Francisco, CA, USA; and
³ Department of Orthodontics and Pediatric Dentistry, School of Dentistry, University of Michigan, Ann Arbor, USA;

Correspondence: ^* corresponding author, shigebon{at}hiroshima-u.ac.jp

The association between mechanical stimulation and chondrocyte homeostasis has been reported. However, the participation of PTHrP (parathyroid-hormone-related protein) in the mechano-regulation of chondrocyte metabolism remains unclear. We determined whether mechanical stimulation of chondrocytes induces the expression of PTHrP and, further, whether the mechano-modulation of PTHrP is dependent on the maturational status of chondrocytes. Cyclic mechanical strain was applied to rat growth plate chondrocytes at the proliferating, matrix-forming, and hypertrophic stages at 30 cycles/min. Cyclic mechanical strain significantly increased PTHrP mRNA levels in chondrocytes at the proliferating and matrix-forming stages only. The induction of PTHrP was dependent on loading magnitude at the proliferating stage. Using specific ion channel blockers, we determined that mechano-induction of PTHrP was inhibited by nifedipine, a Ca²⁺ channel blocker. These results suggest that mechanical induction of PTHrP possibly provides the environment for greater chondrocyte replication and matrix formation that would subsequently affect cartilage formation.

Key Words: mechanical strain • chondrocytes • PTHrP • ion channels

Journal of Dental Research, Vol. 84, No. 1, 64-68 (2005)
DOI: 10.1177/154405910508400111


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				C Boileau, J Martel-Pelletier, J Brunet, D Schrier, C Flory, M Boily, and J-P Pelletier PD-0200347, an {alpha}2{delta} ligand of the voltage gated calcium channel, inhibits in vivo activation of the Erk1/2 pathway in osteoarthritic chondrocytes: a PKC{alpha} dependent effect Ann Rheum Dis, May 1, 2006; 65(5): 573 - 580. [Abstract] [Full Text] [PDF]