Osteoblasts: Novel roles in orchestration of skeletal architecture

Abstract

Osteoblasts are located on bone surfaces and are the cells responsible for bone formation through secretion of the organic components of bone matrix. Osteoblasts are derived from mesenchymal osteoprogenitor cells found in bone marrow and periosteum. Following a period of secretory activity, osteoblasts undergo either apoptosis or terminal differentiation to form osteocytes surrounded by bone matrix. Osteoblasts secrete a characteristic mixture of extracellular matrix proteins including type I collagen as the major component as well as proteoglycans, glycoproteins and γ-carboxylated proteins. Cells of the osteoblast lineage also provide factors essential for differentiation of osteoclasts (bo..