ABSTRACT
Skeletal cells and their environment determine bone mass. Cells of the osteoblastic lineage and signals that determine their replication and differentiation to mature osteoblasts, and signals determining the apoptosis of mature osteoblasts and osteocytes, define the cell population that regulates bone formation. Cells of the osteoclastic lineage and signals that determine their recruitment, genesis, function and death define the cell population that regulates bone resorption. Consequently, bone remodeling is determined by two cell populations and the signals affecting their fate and function. These signals are systemic and local, and include hormones and growth factors. Recent research has focused on local signals, including cell-to-cell interactions, their downstream events and their impact on the fate and function of cells of the osteoblastic lineage.
