Figure 3

The role of Dickkopf-1 (Dkk-1) in bone development. Adapted from Joseph J. Pinzone et al. [6] (with permission). RANKL, a protein expressed on the osteoblast cell membrane, binds to RANK, a receptor located on the osteoclast membrane. RANKL – RANK interaction induces osteoclast differentiation and bone resorption. OPG neutralizes the binding of RANKL to RANK and prevents bone resorption. The Dkk-1 is a soluble inhibitor blocks maturation of osteoblasts and lowers OPG levels, resulting in reduced bone accretion and increased osteolytic activity.