TIEG1 mediates Runx2 expression in osteoblasts following TGFβ1 and BMP2 stimulation.

(A) Calvarial osteoblasts isolated from three wild-type (WT) and three TIEG1 knockout (KO) neonatal pups were treated with vehicle, TGFβ1 or BMP2 for 2 hours. Total RNA was isolated and Runx2 expression levels were monitored by real-time PCR. The results are expressed as relative fold change compared to vehicle treated cells and represent average Runx2 expression across three distinct cell lines. (B) WT calvarial osteoblasts were transfected with a scrambled (NT) or TIEG1 specific siRNA for 24 hours and subsequently treated with vehicle, TGFβ1 or BMP2 for 2 hours. Total RNA was isolated and Runx2 expression levels were determined by real-time PCR relative to vehicle controls. Asterisks denote significance at the p<0.05 level (ANOVA) compared to vehicle controls. δ denotes significance at the p<0.05 level (ANOVA) between WT and KO cells (A) or between WT cells transfected with either a scrambled (NT) or TIEG1 specific siRNA (B).