The Role of the Wnt Signaling Pathway in the Osteogenic Differentiation of Human Adipose-derived Stem Cells under Mechanical Stimulation

This study investigates the effects of the Wnt signaling pathway on the osteogenic differentiation of human adipose-derived stem cells (hASCs) under tensile stress. hASCs cultured in vitro were divided into 4 groups: Group A, hASCs; Group B, Wnt5a RNAi-treated hASCs; Group C, hASCs under tensile stress; and Group D, Wnt5a RNAi-treated hASCs under tensile stress. Five days after treatment, the genes associated with the Wnt/beta-catenin and Wnt/Ca2+ pathways were analyzed in all groups by real-time RT-PCR; the Wnt10b, Wnt5a, RUNX2 and SPP1 proteins were analyzed by western blot analysis. Compared with the expression in Groups A and B, all the genes and proteins in Groups C and D had higher expression, except for Wnt5a in Group D. Compared with Group C, Wnt5a, RhoA, RUNX2 and ALPL had lower expression in Group D, but the markers associated with Wnt/beta-catenin had higher expression. The results suggest that tensile stress can promote maturation and osteogenic differentiation in hASCs and also activate the Wnt/beta-catenin and Wnt/Ca2+ pathways. The Wnt/Ca2+ pathway may have the potential to inhibit the Wnt/beta-catenin pathway. Wnt5a knock down seemed to increase the expression of the Wnt/beta-catenin pathway, which is activated by Wnt10b.