Transforming growth factor-β1 regulates expression of the matrix metalloproteinase 20 (Mmp20) gene through a mechanism involving the transcription factor, myocyte enhancer factor-2C, in ameloblast lineage cells.
Matrix metalloproteinase-20 (Mmp20) plays an essential role in amelogenesis during tooth development and is regulated by transforming growth factor-β1 (TGF-β1) in mouse ameloblast lineage cells (ALCs). The objective of this study was to explore the role of myocyte enhancer factor-2C (MEF2C), a key transcription factor in craniofacial development, in TGF-β1-induced Mmp20 gene expression. We investigated Mmp20 expression in ALCs over-expressing MEF2C and in ALCs with MEF2C knocked down. We also analyzed activity of the Mmp20 promoter using a transient reporter gene-expression assay in cultured ALCs. Putative transcription factor-binding sites for MEF2C and TGF-β1 on the Mmp20 promoter were analyzed with bioinformatics tools and examined using an electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP). The expression of Mmp20 was induced, in a dose-dependent manner, by MEF2C over-expression, and TGF-β1-induced Mmp20 expression was blocked by MEF2C knockdown in ALCs. There was a TGF-β1/MEF2C-responsive region, including a putative MEF2-binding site, between base pairs -356 and -73 of the Mmp20 promoter. Mutation of the putative MEF2-binding site significantly reduced Mmp20 promoter activity upon activation with MEF2C or TGF-β1. In conclusion, TGF-β1-induced Mmp20 expression in ALCs was regulated through the MEF2-binding site on the Mmp20 promoter and thus mediated by the MEF2C signaling pathway.
Department of Stomatology, Hospital affiliated to Binzhou Medical University, Binzhou City, China.
Yuguang
Y
Gao
Li
L
Zhang
Lili
L
Xiang
Bohan
B
Li
Xiaoying
X
Liu
Yumin
Y
Wang
Yan
Y
Sun
D000565:Ameloblasts / Q000201:enzymology / Q000378:metabolism*; D000566:Amelogenesis / Q000235:genetics; D000818:Animals; D020029:Base Pairing / Q000235:genetics; D002460:Cell Line; D019070:Cell Lineage; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics; D055785:Gene Knockdown Techniques; D017930:Genes, Reporter / Q000235:genetics; D057809:HEK293 Cells; D006801:Humans; D064326:MEF2 Transcription Factors / Q000235:genetics; D053519:Matrix Metalloproteinase 20 / Q000235:genetics*; D051379:Mice; D009154:Mutation / Q000235:genetics; D009687:Nuclear Proteins / Q000032:analysis; D010957:Plasmids / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D015398:Signal Transduction / Q000235:genetics; D014158:Transcription, Genetic / Q000235:genetics*; D014162:Transfection; D053773:Transforming Growth Factor beta1 / Q000235:genetics*
D064326:MEF2 Transcription Factors; C578041:Mef2c protein, mouse; D009687:Nuclear Proteins; C508961:Tgfb1 protein, mouse; D053773:Transforming Growth Factor beta1; D053519:Matrix Metalloproteinase 20; C507113:Mmp20 protein, mouse
ameloblast; matrix metalloproteinase 20; myocyte enhancer factor 2C; transforming growth factor-β1