The Possible Role of Neutrophils in the Induction of Osteoclastogenesis

Figure 4

LPS-activated cPMNs do not stimulate osteoclastogenesis in cocultures with osteoclast precursors. Cells were stained for tartrate-resistant acid phosphatase (TRACP, green) and counterstained with the permeable nuclei dye 4,6-diamidino-2-phenylindole (DAPI, blue). (a) Preosteoclasts (monocytes) were cultured for 10 days with M-CSF and RANKL. Formed osteoclasts are indicated with arrows. (b) Preosteoclasts (monocytes) were cultured for 10 days with M-CSF and unstimulated cPMNs. No osteoclasts were formed in this condition. (c) Preosteoclasts (monocytes) were cocultured with LPS-activated (100 ng/mL, 48 hours) cPMNs. In this condition, no osteoclasts were observed. Representative micrographs of three independent experiments are shown. Scale bars represent 100 μm.

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