Role of RANKL in the regulation of NFATc1 and c­Src mRNA expression in osteoclast­like cells.

This study was designed to determine the effects of receptor activator of nuclear factor κB ligand (RANKL) on the mRNA expression of nuclear factor of activated T-cells, cytoplasmic, calcineurin-dependent 1 (NFATc1) and c­Src in rat osteoclast­like cells. The marrow cells were exposed to macrophage colony-stimulating factor (M­CSF; 25 ng/ml) and different concentrations of RANKL (0, 50, 75 and 100 ng/ml) for 9 days. The mRNA expression of NFATc1 and c­Src was determined by polymerase chain reaction. Compared with the M­CSF (25 ng/ml)+RANKL (0 ng/ml) group, the levels of NFATc1 and c­Src mRNA expression were significantly increased in the M­CSF (25 ng/ml)+RANKL (75 and 100 ng/ml) groups (P<0.01, P<0.01, P<0.01 and P<0.01, respectively). Compared with the M­CSF (25 ng/ml)+RANKL (50 ng/ml) group, the levels of NFATc1 and c­Src mRNA expression was significantly increased in the M­CSF (25 ng/ml)+RANKL (75 and 100 ng/ml) groups (P<0.05, P<0.01, P<0.01 and P<0.01, respectively). Compared with M­CSF (25 ng/ml)+RANKL (75 ng/ml) group, the levels of NFATc1 and c­Src mRNA expression was significantly increased in the M­CSF (25 ng/ml)+RANKL (100 ng/ml) group, (P<0.01 and P<0.01, respectively). These data suggest that RANKL could regulate the expression of NFATc1 and c­Src mRNA in the marrow culture system.