Cartilage-derived morphogenetic proteins enhance the osteogenic protein-1-induced osteoblastic cell differentiation of C2C12 cells.
Previous studies have shown that osteogenic protein-1 (OP-1; also known as BMP-7) induces differentiation of the pluripotent mesenchymal cell line C2C12 into osteoblastic cells. OP-1 also alters the steady-state levels of messenger RNA (mRNA) encoding for the cartilage-derived morphogenetic proteins (CDMPs) in C2C12 cells. In the present study, the effects of exogenous CDMPs on bone cell differentiation induced by OP-1 in C2C12 cells were examined. Exogenous CDMP-1, -2, and -3 synergistically and dose-dependently enhanced OP-1 action in stimulating alkaline phosphatase (AP) activity and osteocalcin (OC) mRNA expression. AP staining studies revealed that the combination of OP-1 and CDMP enhanced OP-1 action by stimulating those cells that had responded to OP-1 and not by activating additional cells. The combination did not change the mRNA expression of the BMPs and their receptors. CDMP-1 enhanced the suppression of the OP-1-induced expression of the myogeneic differentiation regulator MyoD. CDMP-1 and OP-1 alone stimulated Smad5 protein expression, but the combination of OP-1 and CDMP-1 stimulated synergistically Smad5 protein expression. Thus, one mechanism of the observed synergy involved enhancement of the induced Smad5 protein expression. At the same protein concentration, CDMP-1 is most potent in enhancing OP-1 activity in inducing osteoblastic cell differentiation of C2C12 cells. CDMP-3 is about 80% as potent as CDMP-1, and CDMP-2 is the least potent (about 50% of CDMP-1).
Yeh
Lee-Chuan C
LC
Department of Biochemistry, The University of Texas Health Science Center, San Antonio, Texas 78229-3900, USA. carolyeh@biochem.uthscsa.edu
Tsai
Alicia D
AD
Zavala
Michelle C
MC
Lee
John C
JC
D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins; D055419:Bone Morphogenetic Protein 7; D052004:Bone Morphogenetic Protein Receptors; D019485:Bone Morphogenetic Proteins / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects*; D002460:Cell Line; D017077:Culture Media, Conditioned / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D055428:Growth Differentiation Factor 5; D051379:Mice; D017570:MyoD Protein / Q000235:genetics; D010006:Osteoblasts / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D015675:Osteocalcin / Q000235:genetics; D010750:Phosphoproteins / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017978:Receptors, Growth Factor / Q000235:genetics; D051902:Smad5 Protein; D015534:Trans-Activators / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics; D016212:Transforming Growth Factor beta / Q000378:metabolism* / Q000494:pharmacology
D000469:Alkaline Phosphatase; D051792:Basic Helix-Loop-Helix Proteins; D055419:Bone Morphogenetic Protein 7; D052004:Bone Morphogenetic Protein Receptors; D019485:Bone Morphogenetic Proteins; D017077:Culture Media, Conditioned; D004268:DNA-Binding Proteins; D055428:Growth Differentiation Factor 5; D017570:MyoD Protein; D015675:Osteocalcin; D010750:Phosphoproteins; D012333:RNA, Messenger; D017978:Receptors, Growth Factor; D051902:Smad5 Protein; D015534:Trans-Activators; D014157:Transcription Factors; D016212:Transforming Growth Factor beta; C503815:Scx protein, mouse; C497798:Smad5 protein, mouse; C493866:cartilage-derived morphogenetic protein-3 protein, mouse; C090394:cartilage-derived-morphogenetic protein-2