The origin, development and regulation of osteoclasts

Osteoclasts, the multinucleated cells primarily responsible for dissolution of bone tissue, form by fusion of precursors that circulate in the bloodstream. A variety of factors have been shown to affect the mature osteoclast and its progenitor cell, such as calcium‐regulating hormones, products of the immune system, and constituents of the arachidonic acid cascade. To date, however, the osteoclast precursor has not been identified. Furthermore, there is limited information on the factors that influence osteoclast development and regulation, reflecting in part the paucity of data on the osteoclast cell surface. Recent progress in understanding osteoclasts formation and function is discussed.