Figure 4.

Nampt reduces the expression of osteoclast-specific genes. BMMs were pretreated with or without Nampt (500 ng/ml) for 1 h in the presence of M-CSF (30 ng/ml) and then stimulated with RANKL (100 ng/ml) for the indicated times. Total RNA was isolated from cells using QIAzol reagent and the mRNA expression levels of TRAP, OSCAR, cathepsin K, CTR, Atp6vOd2, DC-STAMP, β3-integrin and αv-integrin were evaluated by reverse transcription-quantitative polymerase chain reaction. ***P<0.001 vs. control group at the indicated time. BMMs, bone marrow macrophages; CTR, calcitonin receptor; DC-STAMP, dendritic cell-specific transmembrane protein; M-CSF, macrophage colony-stimulating factor; Nampt, nicotinamide phosphoribosyltransferase; OSCAR, osteoclast-associated receptor; RANKL, receptor activator of nuclear factor-κB ligand; TRAP, tartrate-resistant acid phosphatase.