Bone morphogenetic protein receptor in the osteogenic differentiation of rat bone marrow stromal cells.
OBJECTIVE
Several signaling pathways have been shown to regulate the lineage commitment and terminal differentiation of bone marrow stromal cells (BMSCs). Bone morphogenetic protein (BMP) signaling has important effects on the process of skeletogenesis. In the present study, we tested the role of bone morphogenetic protein receptor (BMPR) in the osteogenic differentiation of rat bone marrow stromal cells in osteogenic medium (OM) with or without BMP-2.


METHODS
BMSCs were harvested from rats and cultured in OM containing dexamethasone, beta-glycerophosphate, and ascorbic acid, with or without BMP-2 in order to induce osteogenic differentiation. The alkaline phosphatase (ALP) activity assay and von kossa staining were used to assess the osteogenic differentiation of the BMSCs. BMPR mRNA expression was assessed using reverse transcriptionpolymerase chain reaction (RT-PCR).


RESULTS
The BMSCs that underwent osteogenic differentiation in OM showed a higher level of ALP activity and matrix mineralization. BMP-2 alone induced a low level of ALP activity and matrix mineralization in BMSCs, but enhanced the osteogenic differentiation of BMSCs when combined with OM. The OM significantly induced the expression of type IA receptor of BMPR (BMPRIA) and type II receptor of BMPR (BMPRII) in BMSCs after three days of stimulation, while BMP-2 significantly induced BMPRIA and BMPRII in BMSCs after nine or six days of stimulation, respectively.


CONCLUSIONS
BMSCs commit to osteoblastic differentiation in OM, which is enhanced by BMP-2. In addition, BMP signaling through BMPRIA and BMPRII regulates the osteogenic differentiation of rat BMSCs in OM with or without BMP-2.
Wang
Anxun
A
Department of Oral and Maxillofacial Surgery, The First Affiliated Hospital, Sun Yat-sen University, 58 Zhongshan Road II, Guangzhou, 510080, PR China. anxunwang@yahoo.com
Ding
Xueqiang
X
Sheng
Shihu
S
Yao
Zhaoyou
Z
D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D055396:Bone Morphogenetic Protein 2 / Q000494:pharmacology; D052004:Bone Morphogenetic Protein Receptors / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D003470:Culture Media / Q000494:pharmacology; D008297:Male; D010012:Osteogenesis / Q000187:drug effects / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017154:Stromal Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*
D055396:Bone Morphogenetic Protein 2; D003470:Culture Media; D052004:Bone Morphogenetic Protein Receptors; D000469:Alkaline Phosphatase