OBJECTIVETo evaluate the expression of dentin sialophosphoprotein (DSPP) in transfected rat bone marrow mesenchymal stem cells (BM-MSC) and the influence of the transfection.

METHODSPlasmid containing mice dentin DSPP was constructed by using the cytomegalovirus (CMV) promoter and then transfected the cultured BM-MSC by lipofectamine; The expression of Pax-9 and dentin matrix protein 1 (DMP1) gene of transfected BM-MSC were detected by RT-PCR. The expression of DSPP was examined by immunocytochemical staining, and the formation ratio of mineralized nodules of transfected BM-MSC was compared with untransfected ones after mineralized induction.

RESULTSThe constructed pcDNA3.1(+)/mDSPP could produced 3.0 kb and 5.4 kb fragments, DSPP gene and Pax9 gene were expressed 24 h and 48 h respectively, after BM-MSC were transfected Pax-9 gene was exprssed, but DMP1 gene was not; Immunohistochemical staining showed that DSPP was positive in transfected BM-MSC; The formation ratio of mineralized nodules of transfected BM-MSC was higher than that of untransfected ones after mineralized induction.

CONCLUSIONSThe expression of mice DSPP in BM-MSC by gene transfection can induce the expression of tooth development-associated gene Pax9 and enhance the formation of mineralized nodules, which suggests that DSPP gene might induce odontogenic differentiation of BM-MSC.