Within the past few years, information regarding osteocyte function as been emerging and expanding significantly. No longer is the osteocyte considered a passive cell acting simply as a 'placeholder' within mineralized bone. Osteocytes are derived from osteoblast progenitors and in the adult skeleton compose 90-95% of all bone cells. Therefore, the function of these cells in the adult and aging skeleton has become the focus of recent investigation. These cells are proving to be multifunctional, ranging from mechanotransduction, to regulation of mineral homeostasis, to control of bone remodeling. The osteocyte as a source and reservoir of signaling factors important in health and maintenance of the adult skeleton is addressed in this review.
Adult ; Aging ; Bone Remodeling ; Homeostasis ; Humans ; Osteoblasts ; Osteocytes ; Skeleton

With additional functions of osteocytes being identified, the concept that osteocytes are just "static lacunar-dwelling cells" is no longer accepted. We reviewed most of the relevant literature on osteocyte's function in the direct remodeling of the perilucunar matrix, discussing the advantages and disadvantages. Special attention was paid to how the negative researchers argue about the "osteocytic osteolysis" principle, and how the positive side addressed the arguments. We also discussed the newly found data of osteocytic remodeling function from our group. With more biotechnology in hand, there is increased excitement in the prospect of now being able to answer the two important questions: do osteocytes have the capability to remove mineral from the perilacunar matrix and if so what are the molecular and cellular mechanisms? do osteocytes have the capability to deposit new mineral on the perilacunar matrix and if so what are the cellular and molecular mechanisms?
Animals ; Bone Matrix ; physiology ; Bone Remodeling ; physiology ; Humans ; Osteocytes ; physiology ; Osteogenesis ; physiology ; Osteolysis ; physiopathology