title: Regulation of matrix metalloproteinase-13 and tissue inhibitor of matrix metalloproteinase-1 gene expression by WNT3A and bone morphogenetic protein-2 in osteoblastic differentiation.
abstract: During bone remodeling, degradation of skeletal connective tissue is regulated, at least in part, by the balance between matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinase (TIMPs), their natural inhibitors. Recently, the Wnt signaling pathway has been demonstrated to play a crucial role in the regulation of bone formation. Here, we investigated a potential role for Wnt signaling and functional cross-talk with bone morphogenetic protein (BMP)-2 in mRNA expression of MMPs, TIMPs and bone matrix proteins in pluripotent C2C12 cells. To assess the functional contribution of Wnt signaling, we have generated C2C12 cell lines stably over-expressing Wnt3a or Wnt5a, and then treated these cells with BMP-2 for 24 h. In these cultures, MMP-13 mRNA expression was induced by BMP-2 in Wnt3a over-expressing C2C12 (Wnt3a-C2C12) cells but not in either Wnt5a over-expressing C2C12 (Wnt5a-C2C12) cells or vehicle-transfected C2C12 cells. MMP-13 mRNA was induced in these cells by addition of BMP-2 for 12 h and the enhancement lasted up to 48 h. These effects were observed in a dose-dependent manner. Enzymatic activity of MMP-13 also induced in Wnt3a-C2C12 cells by addition of BMP-2. However, membrane type-1 matrix metalloproteinase (MT1-MMP) and MMP-2 mRNA expression was not affected by either Wnt3a or BMP-2. In contrast, TIMP-1 mRNA expression was suppressed by BMP-2 in Wnt3a-C2C12 cells but not in Wnt5a-C2C12 cells. Our results show that expression of MMP-13 and TIMP-1 is regulated by Wnt signaling combined with BMP-2 in osteoblastic differentiation, and this signaling may in part mediate MMP-13 and TIMP-1 production during bone formation and/or remodeling.
authors.affiliation: Department of Biochemistry and Molecular Biology, Graduate School of Dental Medicine, Hokkaido University, Sapporo, 060-8586, Japan.
authors.forename: Aiko
authors.initials: A
authors.lastname: Nakashima
authors.forename: Masato
authors.initials: M
authors.lastname: Tamura
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000096:biosynthesis*; D002454:Cell Differentiation; D002460:Cell Line; D017364:Collagenases / Q000096:biosynthesis*; D050659:Core Binding Factor Alpha 1 Subunit / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D015971:Gene Expression Regulation, Enzymologic; D053509:Matrix Metalloproteinase 13; D051379:Mice; D015233:Models, Statistical; D010006:Osteoblasts / Q000166:cytology / Q000201:enzymology* / Q000378:metabolism; D015675:Osteocalcin / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000096:biosynthesis*; D014162:Transfection; D016212:Transforming Growth Factor beta / Q000096:biosynthesis*; D051153:Wnt Proteins / Q000096:biosynthesis* / Q000378:metabolism; D000071818:Wnt-5a Protein; D060508:Wnt3 Protein; D060509:Wnt3A Protein
chemical_list: C525719:Bmp2 protein, mouse; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D050659:Core Binding Factor Alpha 1 Subunit; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; C493716:Runx2 protein, mouse; D019715:Tissue Inhibitor of Metalloproteinase-1; D016212:Transforming Growth Factor beta; D051153:Wnt Proteins; D000071818:Wnt-5a Protein; D060508:Wnt3 Protein; D060509:Wnt3A Protein; C555511:Wnt3a protein, mouse; C438615:Wnt5a protein, mouse; D015675:Osteocalcin; D000469:Alkaline Phosphatase; D017364:Collagenases; D053509:Matrix Metalloproteinase 13; C507081:Mmp13 protein, mouse