ABSTRACT
PURPOSE: In humans, nineteen types of WNT genes (WNTs) have been hightlighted up to date. The canonical Wnt cascade has recently emerged as a critical regulator of stem cells. To obtain new insights how nineteen WNTs affect mesenchymal stem cells differentiation, we analyzed the transcriptional activity, osteogenic and adipogenic activity of WNTs in mesenchymal stem cells. MATERIALS AND METHODS: Recombinant adenoviruses expressing nineteen WNTs were constructed to infect pluripotent mesenchymal progenitor C3H10T1/2 cells. Transcriptional activity was determined by using the luciferase reporter assay. Osteogenic activity was determined by measuring the induction of alkaline phosphatase upon Wnt stimulation. Adipogenic activity was measured by histochemical Oil red-O staining. RESULTS: WNT1, 2, 3, 3A and 10B significantly induced transcriptional activity in C3H10T1/2 cells. WNT1, 2, 3, 3A and 10B significantly induced alkaline phosphatase activity, but inhibited adipogenic activity in C3H10T1/2 cells. The results of qualitative and quantitative assay of alkaline phosphatase activity were consistent with those of luciferase assay for transcriptional activity and Oil red-O staining for adipogenic activity. CONCLUSION: We could expect that WNT1, 2, 3, 3A and 10B may play a crucial role in inducing osteoblast differentiation of mesenchymal stem cells.