Basic Biology of Bone Cells
Osteoclastic activity excavates a resorption lacunae on a bone surface. During this process regulatory molecules (growth factors) are released from the bone matrix into the surrounding extracellular space. These growth factors stimulate the proliferation of osteoprogenitor cells which eventually replace the resorbed bone. Because bone formation is localized to the resorption lacunae, there must also be present a mechanism for directing the site of new bone synthesis. An imbalance between resorption and formation leads to metabolic bone diseases.
Diseases such as osteoporosis occur in older adults because the cells responsible for bone resorption and bone formation fail to communicate with each other like they did when the person was younger. Experimental investigations in this area focus on identifying new principles of cell/cell communication. We are currently studying two new gene products that may contribute to the loss of skeletal mass with aging.