ISSN:
0021-9541
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
Using MG-63 cells as a model system capable of partial osteoblastic differentiation, we have examined the effect of growth on extracellular matrix. MG-63 cell matrix and purified type I collagen induced a morphological change characterized by long cytoplasmic processes reminiscent of those seen in osteocytes. Concurrent biochemical changes involving bone marker proteins included increased specific activity of cell-associated alkaline phosphatase and increased secretion of osteonectin (up to 2.5-fold for each protein); all changes occurred without alterations in the growth kinetics of the MG-63 cells. The increase in alkaline phosphatase activity was maximal on days 6-8 following seeding; increased osteonectin secretion was most prominent immediately following seeding; all changes decreased as cells reached confluence. Growing cells on type I collagen resulted in an increased induction of alkaline phosphatase activity by 1,25 (OH)2D3 (with little change in the 1,25 (OH)2D3 induction of osteonectin and osteocalcin secretion), and increased TGF-β induction of alkaline phosphatase activity as well (both TGF-β1 and TGF-β2). Both the 1,25 (OH)2D3 and TGF-β effects appeared to be synergistic with growth on type I collagen. These studies support the hypothesis that bone extracellular matrix may play an important role in osteoblastic differentiation and phenotypic expression.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jcp.1041530205
