<p>(<b>A</b>) Osx activates the <i>MMP13</i> promoter in a dose-dependent manner. HEK293 cells were transfected with a 1 kb <i>MMP13</i> promoter-luciferase reporter gene without or with increasing amounts of an Osx-expression plasmid as indicated. Luciferase activity was normalized by β-galactosidase activity. Values are presented as the mean ± S.D. (B) Jab1 does not activate <i>MMP13</i> promoter activity. HEK293 cells were transfected with a 1 kb <i>MMP13</i> promoter-luciferase reporter gene without or with increasing amounts of a Jab1-expression plasmid as indicated. Luciferase activity was normalized by β-galactosidase activity. Values are presented as the mean ± S.D. (C) MMP13 promoter activity is inhibited in the presence of Osx siRNA. MC3T3 osteoblastic cells were transfected with a 1 kb <i>MMP13</i> promoter-luciferase reporter gene with siRNA Control or Osx siRNA as indicated. Luciferase activity was normalized by β-galactosidase activity. Values are presented as the mean ± S.D.</p
