title: Identification and analysis of type II TGF-β receptors in BMP-9-induced osteogenic differentiation of C3H10T1/2 mesenchymal stem cells.
abstract: Our previous studies have demonstrated that bone morphogenetic protein 9 (BMP-9) is one of the most efficacious BMPs to induce osteoblast differentiation of mesenchymal stem cells (MSCs). However, the molecular mechanism underlying the BMP-9-induced osteogenic differentiation of MSCs remains to be fully elucidated. In this study, dominant negative (DN) type II TGF-β receptors were constructed and introduced into C3H10T1/2 stem cells, then in vitro and in vivo assays were carried out to analyze and identify the type II TGF-β receptors required for BMP-9-induced osteogenesis. We found that three DN type II TGF-β receptors, DN-BMPRII, DN-ActRII, and DN-ActRIIB, diminished BMP-9-induced alkaline phosphatase (ALP) activity, led to a decrease in BMP-9-induced Smad binding element (SBE)-controled reporter activity, reduced BMP-9-induced expressions of Smad6 and Smad7, and decreased BMP-9-induced mineralization in vitro and ectopic bone formation in vivo, finally resulted in decreased bone masses and immature osteogenesis. These findings strongly suggested that three wild-type II TGF-β receptors, BMPRII, ActRII and ActRIIB, may play a functional role in BMP-9-induced osteogenic differentiation of C3H10T1/2 cells. However, C3H10T1/2 stem cells can express BMPRII and ActRII, but not ActRIIB. Using RNA interference (RNAi), we found that luciferase reporter activity and ALP activity induced by BMP-9 were accordingly inhibited along with the knockdown of BMPRII and ActRII. Taken together, our results demonstrated that BMPRII and ActRII are the functional type II TGF-β receptors in BMP-9-induced osteogenic differentiation of C3H10T1/2 cells.
authors.affiliation: Chongqing Medical University, China.
authors.forename: Ningning
authors.initials: N
authors.lastname: Wu
authors.forename: Yingze
authors.initials: Y
authors.lastname: Zhao
authors.forename: Yibing
authors.initials: Y
authors.lastname: Yin
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jinyong
authors.initials: J
authors.lastname: Luo
mesh_terms: D030301:Activin Receptors, Type II / Q000235:genetics / Q000502:physiology; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001665:Binding Sites / Q000235:genetics; D052006:Bone Morphogenetic Protein Receptors, Type II / Q000235:genetics / Q000502:physiology; D002454:Cell Differentiation / Q000235:genetics / Q000502:physiology*; D002460:Cell Line; D017690:Cell Transplantation; D055427:Growth Differentiation Factor 2 / Q000235:genetics / Q000502:physiology*; D045325:HCT116 Cells; D057809:HEK293 Cells; D006801:Humans; D008297:Male; D059630:Mesenchymal Stem Cells / Q000378:metabolism / Q000502:physiology*; D051379:Mice; D008819:Mice, Nude; D010012:Osteogenesis / Q000235:genetics / Q000502:physiology; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000502:physiology*; D034622:RNA Interference; D000077294:Receptor, Transforming Growth Factor-beta Type II; D018125:Receptors, Transforming Growth Factor beta / Q000235:genetics / Q000502:physiology*; D051905:Smad6 Protein / Q000235:genetics / Q000378:metabolism; D051906:Smad7 Protein / Q000235:genetics / Q000378:metabolism; D014162:Transfection
chemical_list: D055427:Growth Differentiation Factor 2; D018125:Receptors, Transforming Growth Factor beta; D051905:Smad6 Protein; D051906:Smad7 Protein; D017346:Protein Serine-Threonine Kinases; D030301:Activin Receptors, Type II; D052006:Bone Morphogenetic Protein Receptors, Type II; D000077294:Receptor, Transforming Growth Factor-beta Type II; D000469:Alkaline Phosphatase