Elevated Extracellular Calcium Concentrations Induce Type X Collagen Synthesis in Chondrocyte Cultures
Chondrocytes at different stages of cellular differentiation were isolated from the tarsal element (immature chondrocytes) and zones 2 and 3 (mature chondrocytes) of 12-d chick embryo tibiotarsus. The chondrocytes from the two sources differed in their cell morphologies, growth rate and production o...
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Published in | The Journal of cell biology Vol. 115; no. 4; pp. 1171 - 1178 |
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Main Authors | , |
Format | Journal Article |
Language | English |
Published |
United States
Rockefeller University Press
01.11.1991
The Rockefeller University Press |
Subjects | |
Online Access | Get full text |
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Summary: | Chondrocytes at different stages of cellular differentiation were isolated from the tarsal element (immature chondrocytes) and zones 2 and 3 (mature chondrocytes) of 12-d chick embryo tibiotarsus. The chondrocytes from the two sources differed in their cell morphologies, growth rate and production of type X collagen. In 24 h, zone 2 and 3 chondrocytes synthesized 800 times more type X collagen than tarsal chondrocytes. The effect of exogenous CaCl2(5 and 10 mM) on the synthesis of type X collagen by both mature and immature chondrocytes was tested. After a 72-h incubation of zone 2 and 3 chondrocytes with CaCl2type X collagen increased 8-fold with 5 mM and 10-fold with 10 mM Ca2+. [3H]Proline incorporation into culture medium and matrix macromolecules increased 11 and 32% with 5 and 10 mM CaCl2, respectively. Type II collagen synthesis was not affected by elevated extracellular CA2+during this 72-h period. Similar studies with tarsal chondrocytes demonstrated a time- and dose-dependent response to CaCl2with type X collagen levels reaching a 4-fold and 15-fold increase over controls with 5 and 10 mM Ca2+, respectively, at 48 h. Elevated extracellular Ca2+had no effect on cell proliferation. These observations offer the first direct evidence of the induction of type X collagen synthesis with elevated extracellular Ca2+. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0021-9525 1540-8140 |
DOI: | 10.1083/jcb.115.4.1171 |