Fig. 8. HGF and M-CSF enhance bone resorption. Murine bone marrow macrophages were cultured onto dentine slices (A-C) or millennium slides (D-F) for 3 days in the presence of RANKL (100 ng/ml) and M-CSF (10 ng/ml). HGF (50 ng/ml), M-CSF (100 ng/ml) or vehicle alone were added for the next 48 hours and bone resorptive activity was analyzed. (A-C) After indicated treatments, cells plated onto dentine slices were fixed, TRAP stained and subjected to light microscopy. Pits, indicated by arrows, increased in number and area in (B) HGF- and (C) M-CSF-treated OCs compared with the control (A). (D-G) Similar experiments were performed onto millennium slides. At the indicated time, osteoclasts were removed by brief treatment with bleach, and resorptive areas were analyzed by light microscopy (identified as the light blue regions). HGF (E) and M-CSF (F) increased erosion areas by 65% and 58%, respectively, compared with vehicle-treated OCs (D). G shows a control well with no cells. All images are at the same magnification.