Role of collagen in retinoic acid-induced differentiation and down-regulation of TGF-beta receptors in rat preosteoblastic RCT-1 cells.
Retinoic acid induces differentiation of preosteoblastic cells. We have demonstrated that osteoblastic differentiation and down-regulation of transforming growth factor (TGF)-beta receptors requires the interaction of type I collagen with alpha 2 beta 1 integrin (J Biol Chem 271: 3938-3944, 1996). The purpose of this study was to clarify the role of collagen in retinoic acid-induced differentiation and down-regulation of TGF-beta receptors using preosteoblastic RCT-1 cells. Retinoic acid enhanced the expression of alkaline phosphatase and type I collagen, and reduced TGF-beta receptors in these cells. Inhibiting collagen synthesis abolished these changes. Because TGF-beta inhibits osteoblastic differentiation, the changes described here may contribute to the osteoblastic differentiation by retinoic acid.
Kodama
Y
Y
Department of Orthopedic Surgery, University of Tokyo School of Medicine, Japan.
Takeuchi
Y
Y
Kikuchi
T
T
Kurokawa
T
T
Fujita
T
T
Matsumoto
T
T
D000469:Alkaline Phosphatase / Q000235:genetics / Q000378:metabolism; D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects*; D002460:Cell Line; D003094:Collagen / Q000378:metabolism / Q000502:physiology*; D003432:Cross-Linking Reagents; D015536:Down-Regulation; D015870:Gene Expression; D010006:Osteoblasts / Q000378:metabolism*; D011347:Procollagen / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D018125:Receptors, Transforming Growth Factor beta / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000378:metabolism / Q000494:pharmacology; D014212:Tretinoin / Q000494:pharmacology*
D003432:Cross-Linking Reagents; D011347:Procollagen; D012333:RNA, Messenger; D018125:Receptors, Transforming Growth Factor beta; D016212:Transforming Growth Factor beta; D014212:Tretinoin; D003094:Collagen; D000469:Alkaline Phosphatase