Osteoclastogenesis of human peripheral blood, bone marrow, and cord blood monocytes

Abstract

AbstractOsteoclasts are multinucleated bone resorbing cells that can be differentiated from human monocytesin vitro. There are few studies comparing osteoclastogenesis of different monocyte sources. We compared monocytes from human bone marrow (BM), peripheral blood (PB), and umbilical cord blood (CB) and their osteoclastogenic potential by culturing them with osteoclastogenic agents. We also cultured cells without growth factors, as umbilical cord blood monocytes have been reported to be able to fuse spontaneously into osteoclasts. After culture with RANKL and M-CSF, all types of cell cultures developed TRACP -positive multinuclear cells that were able to form resorption pits on human bone slices. Only occasional multinuclear cells and small infrequent resorbed areas could be found in PB and CB-derived cultures without growth factors. BM-derived cells formed greater resorption areas than PB- and CB-derived monocytes. The greatest monocyte population in BM samples were intermediate (CD14++CD16+) and in PB and CB classical monocytes (76.3% and 54.4%, respectively). Our data demonstrates that osteoclast precursor origin can effect the osteoclast function and that osteoclasts can be differentiated from CB samples. Therefore CB can be used in osteoclastin vitrostudies.