How osteoblasts become osteocytes: a decreasing matrix forming process.

Osteocyte matrix inclusion process was studied in an in vitro woven bone nodule formation model where a large number of osteocytes at different degrees of maturation were examined. This work focused on early stages of osteocyte inclusion. This matrix inclusion occurred without a matrix synthesis inversion by the future osteocyte and with maintenance of close cell contacts with the replacing cell. A passive matrix embedding process related to a decreased activity of the osteoblast-osteocyte cell is proposed as a comprehensive pathway from osteoblast to osteocyte. The formation of the osteocyte is therefore presented as a very coordinated space and time related cell-cell interaction between cells of the three cell pools of the bone.