Figure 7.

APO866 and PBEF1 knockdown suppresses osteoclast formation and activity and inhibits NF-κB activity in osteoclast precursors. (A) Human osteoclast precursors were cultured in osteoclastic medium supplemented with receptor activator of NF-κB ligand (RANKL) and macrophage colony-stimulating factor, treated with the indicated concentrations of APO866 for 5–7 days, and then subjected to TRAP staining for quantification of TRAP-expressing multinucleate osteoclasts. (B) Representative photomicrographs demonstrate TRAP staining in osteoclast precursor cultures treated with vehicle (CONT) or 0.1 or 1 nmol/L APO866. (C) Pit-formation assay of mature osteoclasts treated with 0.1 or 1 nmol/L APO866 for 5 days. Inserted photographs demonstrate pit formation by mature osteoclasts on dentine, an effect that was suppressed by APO866 (1 nmol/L). (D) Human osteoclast precursors were infected with lentiviral particles containing scramble or PBEF1 shRNA and then subjected to osteoclast formation assay as in (A). Inserted photographs demonstrate TRAP staining in osteoclast precursor cultures treated with scramble or PBEF1 shRNA. (E) Changes in levels of NF-κB activity in osteoclast precursors treated indicated concentrations of APO866 for 5 days.