Osteocyte and bone structure.

The osteocyte is the most abundant cell type of bone. There are approximately 10 times as many osteocytes as osteoblasts in adult human bone, and the number of osteoclasts is only a fraction of the number of osteoblasts. Our current knowledge of the role of osteocytes in bone metabolism is far behind our insight into the properties and functions of the osteoblasts and osteoclasts.

Fas/CD95 is associated with glucocorticoid-induced osteocyte apoptosis.

Prolonged use of glucocorticoids is associated with decreased bone formation, increased resorption and osteonecrosis, through direct and indirect effects on the activity and viability of bone effector cells, osteoblasts and osteoclasts, and osteocytes. This study has investigated molecular pathways implicated in Dexamethasone-induced apoptosis of osteocytes, using a cell line and primary chicken cells. MLO-Y4 osteocytes were pre-treated with several bisphosphonates representing a range of anti-resorptive activities and conformation/structure relationships, and were subsequently challenged with Dexamethasone.

Osteocyte-specific monoclonal antibody MAb OB7.3 is directed against Phex protein.

Osteocytes are the most abundant cells in bone; however, relatively little is known about their properties and functions. The development of monoclonal antibody MAb OB7.3 directed against chicken osteocytes enabled us to purify osteocytes from enzymatically isolated bone cells.