Abstract
Mesenchymal stem cells (MSCs) are considered a promising candidate for use in cell-based therapy for cartilage repair. To promote understanding of the molecular control of chondrogenesis differentiation in MSCs, we compared the changes in microRNAs during in vitro chondrogenesis process of human bone-marrow mesenchymal stem cells (hBMSCs). MiR-199b-5p was up-regulated significantly during this process. The aim of the study was to investigate the effects of miR-199b-5p on chondrogenic differentiation of C3H10T1/2 MSC cells and explore the underlying mechanisms. MiR-199b-5p mimics or inhibitor were transfected into C3H10T1/2 cells, respectively, and then, the effects of miR-199b-5p on chondrogenic differentiation of C3H10T1/2 cells were detected. The results indicated that miR-199b-5p overexpression inhibited the growth of C3H10T1/2 cells but promoted transforming growth factor-β3 (TGF-β3)-induced C3H10T1/2 cells of chondrogenic differentiation, as supported by enhancing the gene and protein expression of chondrocyte specific markers of SOX9, aggrecan, and collagen type II (Col2a1). In contrast, inhibiting miR-199b-5p notably promoted the proliferation of C3H10T1/2 cells but decreased chondrogenic differentiation. Furthermore, mechanism studies revealed that JAG1 was a direct target of miR-199b-5p by dual luciferase reporter assays. While silencing of JAG1 by isRNA resulted an increase of chondrogenic differentiation. Further, JAG1 knockdown was demonstrated to block the effect of miR-199b-5p inhibition. In conclusion, the present study revealed for the first time that miR-199b-5p was the positive regulators to modulate chondrogenic differentiation of C3H10T1/2 cells by targeting JAG1. These findings may provide a novel insight on miRNA-mediated MSC therapy for cartilage related disorders.