Mesenchymal Stem Cells and Osteoblast Differentiation

Publisher Summary This chapter reviews the currently available paradigms governing development of osteoblasts and other mesenchymal cell types such as chondrocytes, adipocytes, and myoblasts among other mesenchymal cell types. It also discusses evidence for mesenchymal stem cells (MSC) and osteoprogenitor deficiencies in disease and disease models, and the rapidly expanding literature on potential use of MSC in regenerative medicine applications, not only for bone, but also for other tissues and organs. It suggests that bone has the potential to repair itself throughout the life of an organism through the coordinated activities of osteoclasts, derived from hemopoietic stem cells (HSCs), and osteoblasts, derived from mulitpotential stem cells that have been variously termed stromal stem cells, mesenchymal stromal cells, skeletal stem cells, stromal fibroblastic stem cells, and most recently, MSCs among other monikers. This chapter also summarizes that the formation of colonies reflecting specific progenitor cell types provides an estimate of the stem/progenitor cell status in normal or diseased states. Finally, it calls for further research efforts to be done to define both MSC and osteoprogenitor number and differentiation capacity in normal aging and in various disease states including osteoporosis.