Objective To investigate the effects of Osterix (Osx) overexpression on the osteogenic differentiation of human periodontal ligament cells in response to mechanical force.MethodsHuman periodontal ligament cells were isolated and cultured in vitro with explant method. Cells were transfected with either an Osx expression vector pcDNA3.1 flag-Osx or the mock control vector pcDNA3.1 flag. Then, cells were centrifuged for 6 h. After transfection and cen- trification, the expression of Osx mRNA and protein in untransfected cells, mock-transfected cells and Osx-transfected cells were measured by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot respectively. Furthermore, the changes of mRNA expressions of core-binding factor a1 (Cbfa1), alkaline phosphatase (ALP) , osteopontin (OPN) , osteocalcin (OC) , bone sialoprotein (BSP) and collagen protein a1 (Col I ) genes were measured to assess the differentiation of human periodontal ligament cells.Results At 24 h after transfection, Osx mRNA and protein level increased significantly in Osx-transfected cells (P0.05) . Simultaneously, the upregulated mRNA expressions of all the five osteogenic genes were observed (PConclusionThe overexpression of Osx promotes the mechanical stress-induced osteogenic differentiation of human periodontal ligament cells. Osx may be essential for mechanical stress-induced differentiation of human periodontal ligament cells to osteoblastic-like cells and be involved in orthodontic osteogenic remodeling.
