[Experimental study of in osteogenesis in duced by NIH-3T3 cells transfected with bone morphogenetic protein 3 gene].

OBJECTIVE: To investigate the gene expression, protein synthesis and inducing osteogenetic capacity of NIH-3T3 cells transfected with recombinant human bone morphogenetic protein 3 (rhBMP3) gene. METHODS: Gene recombination technique was used to clone the BMP3 cDNA into PcDNA3 vector directly, and to form a recombined BMP3-PcDNA3 cDNA, which was introduced into NIH-3T3 cells by means of lipofectamine transfer. The total RNA of transfected NIH-3T3 cells was then extracted to verify the mRNA expression of BMP3 using Northern blot method. BMP3 protein synthesis and AKP activity in the transfected cells was checked. Then, the NIH-3T3 cells transfected with BMP3 gene were injected into nude mouse muscle to evaluate the inducing osteogenesis in the muscle. RESULTS: BMP3 gene had been inserted into PcDNA3 vector successfully. There was BMP3 mRNA expression in the total RNA of NIH-3T3 cells with the peak level appearing in the 6th week after transfection, and BMP3 protein was found in NIH-3T3 cells, and the AKP level is much higher in the transfected NIH-3T3 cells than in non-transfected NIH-3T3 cells. Histologic examination revealed that there were a large number of chondrocytes and trabeculae seen in the nude mouse muscle 4 weeks after injection of the transfected NIH-3T3 cells. CONCLUSION: BMP3 is a protein that possesses osteogenetic effect. After transfection with BMP3-PCDNA3, BMP3 mRNA expression and protein formation can be found in NIH-3T3 cells, and the transfected NIH-3T3 cells have the effect of inducing osteogenesis in vivo.