[Regulation of osteoclast differentiation by Wnt signals]

Osteoclast differentiation is regulated by receptor activator of NF-κB ligand, colony stimulating factor-1 and osteoprotegerin. These cytokines are derived from osteoblast-lineage cells such as osteoblasts and osteocytes. Wnt has been shown to be critical for osteoblast differentiation through β-catenin dependent canonical and β-catenin independent noncanonical Wnt signals. Recent studies have shown that osteoclastogenesis is also regulated by Wnt signals. This review summarizes recent advances in roles of Wnt signals in bone resorption under physiological and pathological conditions.