HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Services Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (15) Citing Articles via Google Scholar 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.

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;

^* 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

This article has been cited by other articles:

				A. E. BROADUS, C. MACICA, and X. CHEN The PTHrP Functional Domain Is at the Gates of Endochondral Bones Ann. N.Y. Acad. Sci., November 1, 2007; 1116(1): 65 - 81. [Abstract] [Full Text] [PDF]

				N. C. NOWLAN, P. MURPHY, and P. J. PRENDERGAST Mechanobiology of Embryonic Limb Development Ann. N.Y. Acad. Sci., April 1, 2007; 1101(1): 389 - 411. [Abstract] [Full Text] [PDF]

				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]