FIGURE 1.

Current and hypothetical RANKL inhibitors to suppress osteoclastogenesis. Osteoblasts produce RANKL that binds its receptor, RANK, which is located on the surface of osteoclasts and their precursors. This binding stimulates the differentiation of preosteoclasts into multinucleated and mature osteoclasts (as shown by the solid arrow in the left). The process is prevented naturally by OPG and pharmacologically by denosumab, thereby inhibiting osteoclast formation, activity, and survival (as shown by solid arrows in the right). We hypothesized a RANKL inhibitor, the aptamer, which may specifically target RANKL and inhibit osteoclastogenesis (as shown by the dotted arrow in the right).