Experimental Study On The Effects Of Human Bone Morphogenetic Protein 2 Gene Transfection On Fibroblasts

Bone Morphogenetic Proteins (BMP) have much broader biological effects on different cell types, especially in morphogenesis and cell differentiation. BMP can not only induce undifferentiated mesenchymal cells but also fibroblasts, osteoblastic precursor cells and myoblasts to differentiate into osteocyte lineages. BMP has a hopeful prospect in bone repair and fracture healing. The function of exogenous BMP in vivo is temporary, and to induce new bone formation needs a large quantity of BMP. The application of BMP may confront toxocity or side-effects. Whereas gene expressio in vivo is a practical and efficient method to express exogenous gene. The osteocytes and fibroblasts are both originated from the mesenchymal cells. The fibroblasts, osteoblasts and chondroblasts are able to express the phenotype of osteogenesis in bone development and repair. Furthermore, the fibroblasts can be cultured easily and also survive, divide and proliferate if exogenous gene is inserted into them. To further elucidate the mechanism of BMP in regulating cell differentiation and to provide basis for BMP gene therapy, this study centers on the effects of BMP2 gene transfection on fibroblasts and contains the following works:â‘  A 1.2kb fragment containing full length human BMP2 coding region was inserted into pBK-CMV (expressed both in protocaryon and eukaryon) by using predetermined orientation methods, resulting in phagemid expression vector for BMP2 (pBK-B2).â‘¡ pBK-B2 was transfected into NIH3T3 cells by using LipofectAMINE. Positive cell clones were selected with G-418, The stably transfection, expression and secretion of BMP2 in NIH3T3 cells were determined by in situ hybridization, immunohistochemistry and sandwich-in ELISA , respectively. The results showed that BMP2 mRNA was successfully transcripted and expressed in NIH3T3 cells.â‘¢ The changes of the biological behaviors of BMP2 gene transfected cells were obsered. Compared with non-transfected cells, the form of BMP2 gene transfected cells changed from fusiform to polygonal. The BMP2 gene transfected cells showed prolonged doubling time and decreased proliferative ability (P<0.05), but enhanced both ALP activity and OC quantity (P<0.05). The BMP2 gene transfected cells showed the phenotype of...