Fig. 6. RUNX2 activates the proximal Htra1 promoter. (A) Schematics showing five different lengths of Htra1 promoter fragments cloned into pGL3 promoter luciferase vector. (B) Relative luciferase activity of the Htra1 promoter fragments 48h after transfection with Runx2 overexpression vector in primary mesenchymal progenitor cells. RUNX2 significantly increased the luciferase activity of all the Htra1 promoter constructs except the -811 to -439 bp construct. Data were normalized to respective empty vector-transfected cells and represented as percentage activity. Mean ± S.E.M; two-way ANOVA with Bonferroni posthoc test; *, p<0.05; ***, p<0.001.