BMPs Expression in Bone Induction and in Central-Peripheral Skeleton

Objectives: Bone morphogenetic proteins (BMPs),were used in experimental and preclinical study. Clinical systems of bone augmentation are known: transplantation of 1.autogenous bone tissue(taken from the same, or from other bone i.e. hip) 2.processed allo/xenogeneic bone, 3. synthetic substitutes. The aim of this study is evaluate the expression of isoforms of BMPs: - in heterotopically induced osteogenesis, mice model of bone augmentation, - in the different sites of the central and peripheral skeleton, Methods: 1.The HeLa-K cells, human cancer cells were cultured and transplanted into tight muscles of BALB/c mice. Their growth-augmentation is observed after 14 days, and heterotopic ossicles induction formation starts 6 day. The immunohistochemical reaction for BMPs were done on paraffin sections. 2.The samples of 11 bone sites from each 5 human cadavers were taken. Semiquantification of RT-PCR was performed. The mRNA expression of BMPs isoforms in HeLa cells and in bone samples was determined. Results: Immunohistochemical reactions show presence both BMP 4 and 6 in the vicinity of HeLa cells and induced chondroid tissue on the 7 th day after injection of HeLa cells. Expression of BMP-1, 2 3 and 6 were found in HeLa-K line, BMP-5,7 were not expressed. The strong expression of BMP4 in both experimental bone augumentation and in the skeleton confirms crucial involvement of these isoform in osteogenesis. Among the BMPs family gene expression significant differences were observed. Conclusions: Potential of osteogenesis-bone augmentation in experimental condition could be related to the different isoforms of BMPs mRNA expression. Assessing the BMPs expression in the skeleton, it must be stated, that significant differences were observed between central and peripheral skeleton. It can explain the different architecture, composition, mechanic properties, as well as metabolism and regenerative ability of different sites of the skeleton. Supported by Ministry of Science and Informatisation, Grant No. 2PO5C 030 26