Fig. 3.

Hypoxia activates β-catenin signaling. A: UMR 106.01 cells cultured for 96 h under 1% oxygen demonstrate increased total expression and nuclear localization of activated β-catenin compared to cells cultured under 21% oxygen. Addition of recombinant Dkk1 and sclerostin (250 ng/ml) reduced B: UMR 106.01 cells transfected with the β-catenin reporter assay TOPFlash were treated with the hypoxia mimetic DFO, or 100 nM hPTH(l–34) 21% oxygen, or cultured under 1% oxygen, for 24 h. The hypoxia mimetic DFO dose-dependently increased β-catenin transcriptional activity, as did 1% oxygen. Data are presented as Luciferase activity ±SEM, normalized to vehicle control, n = 3–5 per time point per condition. *P<0.05 compared to control or vehicle-treated cells; **P<0.01 compared to control or vehicle cells.