Mesenchymal Stem Cells and Osteogenesis
Osteogenesis is a fundamental bone-forming process that is central to normal skeletal growth and development, skeletal responses to injury (fracture), and pathology resulting from inflammation, ischemia, metabolic/hormonal imbalance, cancer, aging, and genetic abnormalities. Orthopaedic surgical and pharmacologic intervention is often aimed at improving the rate and extent of vascularization and osteogenesis. Osteogenesis requires a healthy population of osteoprogenitor cells that are responsive to molecular cues and able to proliferate and differentiate into bone-forming osteoblasts.
We hypothesize that the mesenchymal stem cell pool of potential osteoprogenitor cells is resident in the microvasculature of all bone tissue, and is not necessarily confined to red bone marrow and rare circulating stem cells. Medicine currently lacks the critical knowledge of how to control and stimulate this pool of precursor cells in order to improve bone healing and skeletal integrity. Osteoprogenitor cells are poorly understood but have obvious applications in skeletal repair and corrective surgery. We have recently initiated a study of the vascular pericyte, because this cell has properties of a multipotent mesenchymal stem cell, including the potential for normal osteogenesis, osteogenic wound/fracture healing, and pathological vascular calcification.