Fig. 6. Effects of HA on RANKL signaling. (A) BMMs were serum-starved, pretreated with HA (1 µg/ml) for 30 minutes, and stimulated with RANKL (500 ng/ml) for indicated times. Cell lysates were immunoblotted. (B) BMMs were cultured for 2 days with M-CSF (30 ng/ml) and RANKL (100 ng/ml) in the presence or absence of HA (1 µg/ml). The pre-conditioned cells were serum-deprived, and cells pre-conditioned in the presence of HA were treated with HA (1 µg/ml) for 30 minutes, whereas cells pre-conditioned in the absence of HA were treated with the vehicle. Cells were then stimulated with RANKL (500 ng/ml) for indicated times. Cell lysates were subjected to western blot analyses.