Effect of recombinant human bone morphogenetic protein-4 on cultured bone marrow stem cells / 中华骨科杂志

ABSTRACT

Objective To produce bioactive human bone morphogenetic protein-4 by Escherichia coli genetic engineering and investigate the effect of the product, recombinant BMP-4, on the bone marrow stem cells. Methods cDNA of human morphogenetic protein-4 mature peptide was obtained by RT PCR from tissue of human placenta. The gene was constructed in the pET-22b(+) expression vector and expressed in Escherichia coli BL-21 after transformation and induction by IPTG. The harvested protein was proved to be bioactive by inducing ectopic bone information in mouse thigh. The protein was applied to induce the cultured bone marrow stem cell. Shape change of the cell, ability of ALP (alkaline phosphatase) and concentration of OC (osteocalcin) were investigated. Results SDS-PAGE revealed a new protein band that located in position of 14?103 after 4 hours induction, the new protein made 15% of total bacteria protein, the rhBMP-4 could induce the cultured bone marrow stem cell of New Zealand rabbit to differentiate into osteoblasts and form calcified node. The ability of ALP and concentration of OC of tested group increased significantly than that of the control group. Conclusion The bioactive rhBMP-4 can be produced by Escherichia coli genic engineering, this protein can induce bone marrow stem cells to differentiate into osteoblast cells.