Freyria AM, Ronziere MC, Roche S, Rousseau CF, Herbage D.
Regulation of growth, protein synthesis, and maturation of fetal
bovine epiphyseal chondrocytes grown in high-density culture in
the presence of ascorbic acid, retinoic acid, and
dihydrocytochalasin B.
J Cell Biochem. 1999 Nov;76(1):84-98.
Institut de Biologie et Chimie des Protéines, CNRS-UPR, 69367
Lyon Cedex 07, France.
Phenotypic expression of chondrocytes can be modulated in
vitro by changing the culture technique and by agents such
vitamins and growth factors. We studied the effects of ascorbic
acid, retinoic acid (0.5 and 10 microM), and dihydrocytochalasin
B (3, 10, 20 microM Dihydrocytochalasin B), separately or in
combination (ascorbic acid + retinoic acid or ascorbic acid +
Dihydrocytochalasin B), on the induction of maturation of fetal
bovine epiphyseal chondrocytes grown for up to 4 weeks at high
density in medium containing 10% fetal calf serum and the
various agents. In the absence of any agent or with retinoic
acid or Dihydrocytochalasin B alone, the metabolic activity of
the cells remained very low after day 6, with no induction of
type I or X collagen synthesis nor increase in alkaline
phosphatase activity. Chondrocytes treated with fresh ascorbic
acid showed active protein synthesis associated with expression
of types I and X after 6 and 13 days, respectively. This
maturation was not accompanied by obvious hypertrophy of the
cells or high alkaline phosphatase activity. Addition of
retinoic acid to the ascorbic acid-treated cultures decreased
the level of type II collagen synthesis and delayed the
induction of types I and X collagen, which were present only
after 30 days. A striking increase in alkaline phosphatase
activity (15-20-fold) was observed in the presence of both
ascorbic acid and the highest dose of retinoic acid (10 microM).
Dihydrocytochalasin B was also a potent inhibitor of the
maturation induced by treatment with ascorbic acid, as the
chondrocytes maintained their rounded shape and synthesized type
II collagen without induction of type I or X collagen. The
pattern of protein secretion was compared under all culture
conditions by two-dimensional gel electrophoresis. The different
regulations of chondrocyte differentiation by ascorbic acid,
retinoic acid, and Dihydrocytochalasin B were confirmed by the
important qualitative and quantitative changes in the pattern of
secreted proteins observed by two-dimensional gel
electrophoresis along the study. Copyright 1999 Wiley-Liss, Inc.
PMID: 10581003 |
