Bone remodeling and the osteoclast.

Bone remodeling is a process initiated by the osteoclast, and thus, its understanding is prerequisite to regulation of bone turnover. The last decade has witnessed major advances in our understanding of osteoclast biology, specifically as relates to the ontogeny of the cell and the mechanisms by which it degrades bone. It is now possible to isolate and generate osteoclasts and maintain them in relative purity. Using these models, a number of laboratories have shown that ion transport by the osteoclast plays a major role in its ability to resorb bone. Furthermore, osteoclast-bone matrix attachment, mediated at least in part by integrins, is pivotal to the resorptive process. These discoveries are likely to lead to insight into control of the remodeling process.