[Icaritin promotes chondrogenic differentiation of BMSCs by Wnt/β-catenin signaling pathway]

To investigate the effect of icaritin (ICT) combined with GDF-5 on chondrogenic differentiation of bone marrow stromal cells (BMSCs), and discuss the action of Wnt signaling pathway, full bone marrow adherent method was used to isolate and culture SD rats BMSCs, and the cells at P3 generation were taken and divided into 6 groups： BMSCs group, ICT group, GDF-5 group, GDF-5+ICT group, GDF-5+ICT+SB216763 group, and GDF-5+ICT+ XAV-939 group. The cells were induced and cultured for 14 days. The morphology change was observed by inverted microscope. Alcian blue staining method was used to detect the changes of proteoglycans. RT-PCR was used to detect the mRNA expressions of aggrecan, Col2, Sox9, Dvl1, Gsk3β, and β-catenin. The protein expressions of collagen 2 (COL2) and β-catenin were detected by Western blot. The results indicated that, compared with the BMSCs group, gradual increase was present in proteoglycan Alcian blue staining; mRNA expressions of cartilage differentiation marker genes aggrecan, COL2, Sox9 and the protein expression of COL2, as well as mRNA and protein expressions of Wnt signaling pathway-related gene β-catenin, but with gradual decrease in Gsk3β mRNA expressions in GDF-5 group, GDF-5+ICT group and GDF-5+ICT+SB216763 group. On the contrary, compared with GDF-5+ICT group, there was a decrease in expressions of Dvl1, and β-catenin related to chondrogenic differentiation and Wnt signaling pathway, a increase in Gsk3β mRNA expression, and also a decrease in protein expressions of COL2 and β-catenin in GDF-5+ICT+XAV-939 group, with statistically significant difference between two groups. GDF-5 in combination with icaritin can induce chondrogenic differentiation of BMSCs in rats, and icaritin (ICT) can promote the chondrogenic differentiation. ICT can promote the chondrogenic differentiation of BMSCs in vitro probably by activating the Wnt/β-catenin signaling pathway.