The Rescue Effect of RANKL on Zoledronate Induced Acid Inhibition of Osteoclastogenesis and Gene Expression of NF-κB p50 and c-Jun

In this study,the rescue effect of receptor activator for nuclear factor-κB ligand(RANKL)on zoledronate acid(ZOL)induced inhibition of osteoclastogenesis and gene expression of NF-κB p50and c-Jun was investigated. Mice calvarial osteoblasts(OBs)were harvested and co-cultured with RAW264.7cells and the cells were divided into 4groups and received treatment with ZOL and RANKL,either single or combined.The formation of multi-nucleated osteoclast(OC)was examined and gene expression of NF-κB p50and c-Jun was detected.Group B(ZOL)showed least multi-nucleated OC and resorption lacunae among the 4groups(P0.05or P0.01)and it was followed by group C(ZOL+RANKL).Group D(RANKL)showed highest OC and resorption lacunae while it was similar to Group A(control)(P0.05).Gene expression of NF-κB p50and c-Jun was the lowest in group B(P0.05or P 0.01)among the four groups and was significantly increased in group C when compared with group B(P0.05). Group A and D showed highest gene expression and they were similar to each other(P0.05).This study suggest that RANKL might partly rescue ZOL induced inhibition of osteoclastogenesis,and the effect of RANKL and ZOL on osteoclastogenesis may be mediated by NF-κB p50and c-Jun.