Rat incisor dentine contains a factor which alters the phenotypic expression and stimulates chondrogenesis in fibroblast-like cells in vitro.
A low molecular weight protein fraction isolated under dissociative conditions during the demineralization of rat incisor dentine has the ability to modulate, in culture, the expression of fibroblast-like cells explanted from neonatal rat muscle. The protein fraction enhances the incorporation of 35S-sulphate into a proteoglycan larger in weight than that produced by the uninduced cells; furthermore it induces the production of type II collagen. These changes take place in the absence of cell proliferation as measured by 3H-thymidine incorporation. The altered fibroblast-like cells form nodules and secrete an abundant extracellular matrix which stains for proteoglycan after 7-9 days in culture. These data show that the dentine matrix does contain a factor which can initiate a mitogenesis-independent alteration in the expression of the muscle-explant outgrowth cells. Those changes are consistent with a shift to a chondrogenic mode.
Division of Oral Biology, Northwestern University Dental School, Chicago, Illinois 60611.
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Veis
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Sires
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Clohisy
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Sabsay
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Amar
D000818:Animals; D002356:Cartilage / Q000254:growth & development*; D002478:Cells, Cultured; D002850:Chromatography, Gel; D003094:Collagen / Q000096:biosynthesis; D003804:Dentin / Q000032:analysis / Q000502:physiology*; D005347:Fibroblasts / Q000502:physiology; D006133:Growth Substances / Q000302:isolation & purification / Q000502:physiology*; D007180:Incisor / Q000032:analysis; D008970:Molecular Weight; D010641:Phenotype; D051381:Rats
D006133:Growth Substances; D003094:Collagen