Development, Vol 117, Issue 1 245-251, Copyright © 1993 by Company of Biologists

JOURNAL ARTICLES

Type VI collagen expression is upregulated in the early events of chondrocyte differentiation

R Quarto, B Dozin, P Bonaldo, R Cancedda and A Colombatti
Laboratorio Differenziamento Cellulare, Istituto Nazionale per la Ricerca sul-Cancro, Genova, Italy.

Dedifferentiated chondrocytes cultured adherent to the substratum proliferate and synthesize large amounts of type I collagen but when transferred to suspension culture they decrease proliferation, resume the chondrogenic phenotype and the synthesis of type II collagen, and continue their maturation to hypertrophic chondrocyte (Castagnola et al., 1986, J. Cell Biol. 102, 2310-2317). In this report, we describe the developmentally regulated expression of type VI collagen in vitro in differentiating avian chondrocytes. Type VI collagen mRNA is barely detectable in dedifferentiated chondrocytes as long as the attachment to the substratum is maintained, but increases very rapidly upon passage of the cells into suspension culture reaching a peak after 48 hours and declining after 5-6 days of suspension culture. The first evidence of a rise in the mRNA steady-state levels is obtained already at 6 hours for the alpha 3(VI) chain. Immunoprecipitation of metabolically labeled cells with type VI collagen antibodies reveals that the early mRNA rise is paralleled by an increased secretion of type VI collagen in cell media. Induction of type VI collagen is not the consequence of trypsin treatment of dedifferentiated cells since exposure to the actin-disrupting drug cytochalasin or detachment of the cells by mechanical procedures has similar effects. In 13-day-old chicken embryo tibiae, where the full spectrum of the chondrogenic differentiation process is represented, expression of type VI collagen is restricted to the articular cartilage where chondrocytes developmental stage is comparable to stage I (high levels of type II collagen expression).(ABSTRACT TRUNCATED AT 250 WORDS)

This article has been cited by other articles:

				B. Brachvogel, H. Moch, F. Pausch, U. Schlotzer-Schrehardt, C. Hofmann, R. Hallmann, K. von der Mark, T. Winkler, and E. Poschl Perivascular cells expressing annexin A5 define a novel mesenchymal stem cell-like population with the capacity to differentiate into multiple mesenchymal lineages Development, June 1, 2005; 132(11): 2657 - 2668. [Abstract] [Full Text] [PDF]

				C Dani, A. Smith, S Dessolin, P Leroy, L Staccini, P Villageois, C Darimont, and G Ailhaud Differentiation of embryonic stem cells into adipocytes in vitro J. Cell Sci., January 6, 1997; 110(11): 1279 - 1285. [Abstract] [PDF]

				P Castagnola, M Gennari, R Morello, L Tonachini, O Marin, A Gaggero, and R Cancedda Cartilage associated protein (CASP) is a novel developmentally regulated chick embryo protein J. Cell Sci., January 6, 1997; 110(12): 1351 - 1359. [Abstract] [PDF]

				S. Piccolo, P. Bonaldo, P. Vitale, D. Volpin, and G. M. Bressan Transcriptional Activation of the alpha1(VI) Collagen Gene during Myoblast Differentiation Is Mediated by Multiple GA Boxes J. Biol. Chem., August 18, 1995; 270(33): 19583 - 19590. [Abstract] [Full Text] [PDF]