TSF/FHA induces osteogenic differentiation of Mc3t3 cells via Pygo2 dependent Wnt/β-catenin signaling pathway

Objectives: This study aimed to investigate whether tussah silk fibroin (TSF)/fluoridated hydroxyapatite (FHA) can promote osteogenic differentiation of Mc3t3 cells and explore the role of Wnt/ss-catenin signaling in this process. Methods: TSF/FHA was gained via freeze drying technique and cyclic phosphate immersion method. The relative expression levels of bone-related genes and proteins of Mc3t3 cells seeded on different materials were examined by RT-qPCR and Western blotting. Knockdown or overexpression of Pygo2 in Mc3t3 cells was achieved using lentiviral transfection. Cell proliferation, the expression of bone-related genes and proteins were subsequently examined. Animal experiment was also performed to observe the osteogenesis effect. Results: Different ratios of fluorine of TSF/FHA accelerated the osteogenic differentiation of Mc3t3 cells and increased the Pygo2 expression. The Wnt/beta-catenin signaling pathway was activated after TSF/FHA induction, accompanied by the increased expression of related genes. In SD rats with skull defect, the newly formed bone increased significantly and the Pygo2 overexpressing Mc3t3 cells promoted osteogenesis. However, Pygo2 knockdown markedly compromised the osteogenesis of Mc3t3 cells after TSF/FHA induction. Conclusion: TSF/FHA facilitates osteogenic differentiation of Mc3t3 cells via upregulating Pygo2 and activating Wnt/beta-catenin signaling pathway.