Noggin expression in a mesodermal pluripotent cell line C1 and its regulation by BMP

Osteoblasts and chondrocytes are derived from mesodermal stem cells and the ir differentiation is under the control of coordinated interaction among si gnaling molecules. Noggin is one of the signaling molecules which bind to a nd inactivate BMPs to induce neural tissues and dorsal mesoderm in Xenopus. However, its expression and regulation in mammalian cells has not been kno wn. In this study, we investigated expression of noggin in murine pluripote nt mesodermal cell line, C1. Noggin expression was very low in these C1 cel ls before they were induced to differentiate. When C1 cells were induced to differentiate into chondrocytes in aggregate cultures in the presence of d examethasone(dex), noggin expression was significantly increased. In a shar p contrast, when the C1 cells were induced to differentiate into osteoblast ic cells by the treatment with beta glycerophosphate (beta GP) and ascorbic acid (AA), noggin mRNA expression remained to be barely detectable. Noggin expression was also observed in the developing cartilage of vertebrae in 1 5.5 dpc mouse embryos. The noggin mRNA level in C1 cells in monolayer cultu res was enhanced significantly by the treatment with BMP4/7 in a dose-depen dent manner with a maximal effect at 100 ng/ml. The BMP4/7 effect on noggin expression was time dependent starting within 12 h and peaked at 24 h. The se results indicate that noggin is expressed in the pluripotent mesodermal cell line C1 and that its expression is regulated by BMP. (C) 1999 Wiley-Li ss, Inc.