[Cell adhesion molecule in osteobrast biology]

Investigation of integrins among cell adhesion molecules has revealed that bone matrix proteins including type I collagen play a pivotal role in the regulation of osteoblastic differentiation via their binding to integrins on osteoblasts. It is now suggested that cell-matrix interactions are critically involved in bone formation by osteoblasts. Cell-cell interactions among osteoblasts and hematopoietic cells are also mediated by cell adhesion molecules including integrins. Recently, it is reported that adhesion of osteoclast precursors to osteoblasts via cell adhesion molecules supports the formation of bone resorbing osteoclasts. These observations indicate that cell adhesion molecules on osteoblasts are functionally involved in bone metabolism.