Small Molecule-BIO Accelerates and Enhances Marrow-Derived Mesenchymal Stem Cell in Vitro Chondrogenesis

Hyaline cartilage defects exhibit a major challenge in the field of orthopedic surgery owing to its limited repair capacity. On the other hand, mesenchymal stem cells (MSCs) are regarded as potent cells with a property of cartilage regeneration. We aimed to optimize marrow-derived MSC chondrogenic culture using a small bioactive molecule referred to as BIO. MSCs from the marrow of NMRI mice were extracted, culture-expanded, and characterized. Micro-mass culture was then established for chondrogenic differentiation (control group). The cultures of MSC in chondrogenic medium supplemented with 0.01, 0.05, 0.1, and 1 µM BIO were taken as the experimental groups. Cartilage differentiation was examined by both histological sections and real-time PCR for Sox9, aggrecan, and collagen II at different time points. Moreover, the involvement of the Wnt pathway was investigated. Based on histological sections, there was seemingly more intense metachromatic matrix produced in the cultures with 0.01 µM BIO. In this experimental group, cartilage-specific genes tended to be upregulated at day 14 compared to day 21 of the control group, indicating the accelerating effect of BIO on cartilage differentiation. Overall, there was statistically a significant increase (P=0.01) in the expression level of cartilage-specific genes in cultures with 0.01 µM BIO (enhancing effects). These upregulations appeared to be mediated through the Wnt pathway evident from the significant upregulation of T-cell factor and beta-catenin molecules (P=0.01). Taken together, BIO at 0.01 µM could accelerate and enhance in vitro chondrogenesis of mouse marrow-derived MSCs.