Wnt and Notch signaling pathways in calcium phosphate-enhanced osteogenic differentiation: A pilot study

Calcium phosphate (CaP) ceramics are being increasingly used to repair critical bone defect for biocompatibility, biosafety, porous structure and osteoinduction. Wnt and Notch signaling pathways are conservative and classic signaling pathways regulating osteogenic differentiation of bone marrow mesenchymal stromal cells (BMSCs). In this study, we evaluated the expression of Wnt, Notch signal pathways and osteogenic related genes of BMSCs with and without Wnt pathway inhibitor DKK1 on CaP ceramics in vitro by real-time RT-PCR. Also, we evaluated new bone formation after implantation of CaP ceramics in vivo. The in vitro culture displayed the expression of Wnt, Notch signaling pathways and osteogenic related genes was increased at first and then declined. After adding DKK1 to the culture, the expression was decreased. The in vivo implantation showed significant bone formation on CaP ceramics. These findings reveal that Wnt and Notch signaling pathways play important roles in the CaP-enhanced osteogenic differentiation but the mechanism of synergistic effect needs to be further explored. (c) 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 107B: 149-160, 2019.