The Effect of BMP 4, 6, and 7 on Osteoclast Differentiation and Resorption

Abstract

Previous research by the Mansky lab has demonstrated that BMP2 enhances RANKL-mediated osteoclast differentiation and activity. To investigate the effects of other BMPs on osteoclast differentiation, I treated bone marrow macrophages with RANKL and increasing concentrations of BMP4, 6 or 7 during osteoclast differentiation. Osteoclasts were TRAP stained and measured and counted using NIH Image J. My results demonstrated that BMP4 and BMP6 increased osteoclast size but not osteoclast number; however, BMP7 increased osteoclast number but not size. Secondly I treated mature multinuclear osteoclasts with increasing concentrations of BMP 4, 6 and 7 to determine the effect of BMP on osteoclast activity. An increase in osteoclast activity was only measured with the addition of BMP7 to mature osteoclasts. My experiments demonstrate that similar to BMP2, BMP4, 6 and 7 enhance RANKL mediated osteoclast differentiation; however, the mechanism by which BMPs enhance differentiation still needs to be explored.