Wnt3a induced increase in OPG mRNA and protein in osteoblast progenitor cells. C2C12 cells (A,C) and Saos-2 cells (B,D) were treated with serial concentrations of recombinant Wnt3a for indicated times. The OPG mRNA (A,B) was amplified by qPCR analysis. The supernatant of treated cells (C,D) was harvested and subjected to ELISA for measurement of OPG protein. Protein in lysate (1 mg) was subjected to the GST-E-cadherin assay. After SDS-PAGE analysis, uncomplexed β-catenin was detected by anti–β-catenin antibody (C,D). The results are means plus or minus SD (n = 4). Results are representative of 3 independent experiments (*P < .05 vs control).