The roles of osteocyte signaling in bone.

Osteocytes are the cells that reside within the bone matrix and make up 90% to 95% of the cellular component of the tissue. Until recently, they were thought to serve as little more than “space holders” in the tissue. However, significant advances have demonstrated that osteocytes are of the utmost importance in regulating the dynamic nature of bone; indeed, it may be that this is their major function. Specifically, osteocyte signaling in skeletal metabolism contributes to (1) regulation of local mineralization, (2) regulation of systemic mineralization, (3) bone formation by osteoblasts, and (4) bone resorption by osteoclasts.