Identification of an autocrine chondrocyte colony-stimulating factor: chondromodulin-I stimulates the colony formation of growth plate chondrocytes in agarose culture.
Chondrocytes are unique among non-transformed cells in that they are capable of anchorage-independent growth in soft agar. Fibroblast growth factor (FGF) is known as a potent colony-stimulating factor for chondrocytes. However, cartilage extracts contain a potent colony-stimulating activity which is not explicable only by contaminating FGF. We previously isolated the 25 kDa cartilage-specific glycoprotein chondromodulin-I (ChM-I) which stimulates the growth of chondrocytes. In the present study, we observed that ChM-I stimulates the colony formation of rabbit growth plate chondrocytes in agarose culture. ChM-I alone weakly stimulated the formation of chondrocyte colonies, but it markedly stimulated colony formation synergistically in the presence of an optimal dose of FGF-2. This effect was dependent on the dose of ChM-I. These results suggest that ChM-I participates in an autocrine signaling mechanism for the anchorage-independent growth of chondrocytes in vitro.
Inoue
H
H
Department of Biochemistry, Osaka University Faculty of Dentistry, Japan.
Kondo
J
J
Koike
T
T
Shukunami
C
C
Hiraki
Y
Y
D000818:Animals; D019898:Autocrine Communication; D002356:Cartilage / Q000166:cytology / Q000187:drug effects*; D002417:Cattle; D002478:Cells, Cultured; D019902:Chondrocytes / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology; D006132:Growth Plate / Q000166:cytology / Q000187:drug effects*; D006133:Growth Substances / Q000302:isolation & purification / Q000494:pharmacology*; D036341:Intercellular Signaling Peptides and Proteins; D008297:Male; D018919:Neovascularization, Physiologic / Q000187:drug effects; D011817:Rabbits; D016212:Transforming Growth Factor beta / Q000494:pharmacology
D006133:Growth Substances; D036341:Intercellular Signaling Peptides and Proteins; D016212:Transforming Growth Factor beta; D016222:Fibroblast Growth Factor 2