title: Carboxyl-terminal propeptide of type I collagen (c-propeptide) modulates the action of TGF-beta on MC3T3-E1 osteoblastic cells.
abstract: Previously we found that the carboxyl-terminal propeptide of type I collagen (c-propeptide) is a major secretory protein of MC3T3-E1 osteoblastic cells. In this study, we found that c-propeptide suppresses collagen synthesis and alkaline phosphatase activity of MC3T3-E1 osteoblastic cells at the early-differentiated stage in a dose dependent manner. Mature osteoblasts did not respond to c-propeptide. These findings imply that c-propeptide modulates the function of osteoblasts at an early differentiation stage. Transforming growth factor-beta (TGF-beta) is stored in bone and released from bone matrix after the resorption by osteoclasts. We investigated the effect of c-propeptide on the action of TGF-beta, and found that it enhanced the effect of TGF-beta. We conclude that c-propeptide is a physiological modulator of TGF-beta in bone metabolism.
authors.affiliation: Department of Biochemistry, School of Dentistry, Hokkaido University, Sapporo, Japan. mmizuno@den.hokudai.ac.jp
authors.forename: M
authors.initials: M
authors.lastname: Mizuno
authors.forename: R
authors.initials: R
authors.lastname: Fujisawa
authors.forename: Y
authors.initials: Y
authors.lastname: Kuboki
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D002460:Cell Line; D003094:Collagen / Q000096:biosynthesis / Q000737:chemistry*; D004305:Dose-Response Relationship, Drug; D007700:Kinetics; D051379:Mice; D010006:Osteoblasts / Q000201:enzymology / Q000378:metabolism; D010455:Peptides / Q000737:chemistry*; D011485:Protein Binding; D016212:Transforming Growth Factor beta / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D010455:Peptides; D016212:Transforming Growth Factor beta; D003094:Collagen; D000469:Alkaline Phosphatase