@article {15872,
	title = {Effect of monocytes/macrophages on the early osteogenic differentiation of hBMSCs},
	journal = {Journal of Tissue Engineering and Regenerative Medicine},
	volume = {7},
	year = {2013},
	month = {2013-05-07 00:00:00},
	pages = {392-400},
	publisher = {Wiley \& Sons, Inc.},
	abstract = {<p class="p1">Heterotypic cell interactions are essential for the homeostasis of bone tissue, in particular the widely studied interaction between osteoblasts and osteoclasts. Closely related with osteoclasts are monocytes/macrophages. These have been shown to produce osteogenic factors, e.g. BMP-2, which plays a key role in bone metabolism. However, the mechanisms through which monocytes/macrophages interact with osteoblasts are still elusive. The aim of this work was to assess the influence of human peripheral blood monocytes/macrophages over the early osteogenic differentiation of human bone marrow stromal cells (hBMSCs) in the presence of dexamethasone-supplemented medium. The co-cultures were performed using porous transwells that allowed the interaction between both cell types through the production of paracrine factors. The potential effect of BMP-2 produced by monocytes/macrophages was addressed by adding an anti-BMP-2 antibody to the co-cultures. hBMSCs cultured in the presence of monocytes/macrophages had a higher proliferation rate than hBMSCs monocultures. The quantification of early osteogenic marker alkaline phosphatase (ALP) revealed higher activity of this enzyme in cells in the co-culture throughout the time of culture. Both of these effects were inhibited by adding an anti-BMP-2 antibody to the cultures. Moreover, qRTPCR for osteocalcin and osteopontin transcripts showed overexpression of both markers. Once again, the effect of monocytes/macrophages over hBMSC osteogenic differentiation was completely inhibited in the co-cultures by blocking BMP-2. The present report confirmed that monocytes/macrophages produce BMP-2, which promotes osteogenic differentiation and proliferation of hBMSCs cumulatively to dexamethasone-supplemented medium. This potentially implies that monocyte/macrophages play a stronger role in bone homeostasis than so far supposed. Copyright (c) 2012 John Wiley \&amp; Sons, Ltd.</p>},
	keywords = {bone biology, cell interactions, macrophages, Monocytes, osteoblasts},
	issn = {1932-6254},
	doi = {10.1002/term.535},
	url = {http://onlinelibrary.wiley.com/doi/10.1002/term.535/abstract},
	author = {Pirraco, R. P. and Reis, R. L. and Marques, A. P.}
}
