Abstract
Osteoblast has been found to exert indispensable functions during fracture healing. This study aimed to investigate the effects of kaempferol, a natural flavonoid compound, on osteoblast proliferation, migration and differentiation, as well as possible molecular mechanisms. qRT-PCR was performed to measure the expression level of microRNA-101 (miR-101). Cell viability and migration were respectively assessed using cell counting kit-8 (CCK-8) assay and two-chamber migration assay. Relative alkaline phosphatase (ALP) activity was evaluated using p-nitrophenyl phosphate (pNPP) as substrate. Western blotting was used to detect the protein expression levels of key molecules involved in cell proliferation, migration, differentiation, and Wnt/β-catenin pathway. Kaempferol treatment significantly promoted MC3T3-E1 cell proliferation, migration, and differentiation. Mechanistically, kaempferol notably enhanced the expression level of miR-101 in MC3T3-E1 cells. Knockdown of miR-101 obviously weakened the promoting effects of kaempferol on MC3T3-E1 cell proliferation, migration, and differentiation. In addition, kaempferol remarkably activated Wnt/β-catenin pathway in MC3T3-E1 cells via up-regulating miR-101. This research further confirmed the promoting effects of kaempferol on osteoblast proliferation, migration, and differentiation. The up-regulation of miR-101 and activation of Wnt/β-catenin pathway caused by kaempferol play critical roles in the promoting effects of kaempferol on osteoblast proliferation, migration, and differentiation.