Methods for investigation of osteoclastogenesis using mouse embryonic stem cells

Investigation of osteoclastogenesis in vivo, especially in early development, has proven difficult because of the accessibility of these early embryonic stages. Our ability to culture embryonic stem cells (ESCs) in vitro has overcome this difficulty as these versatile cells can be expanded endlessly. Thus, the whole process of osteoclastogenesis can be monitored in these cultures through the microscope and with the help of molecular biology techniques. We have developed two methods to induce osteoclasts, the bone matrix remodeling cells, from murine ESCs. Surprisingly, one of these induction methods produces osteoclasts, osteoblasts, and also endothelial cells in the same culture dish. Hence, it is likely that ESCs in culture mimic the in vivo development of osteoclasts.