Bone disease drug discovery: examining the interactions between osteoblast and osteoclast

Background: Existing drugs, including bisphosphonates and calcitonin, cannot meet the strong demand for a possible cure of bone diseases – the prevailing cause of human disabilities. Objectives: To understand on-going drug discovery activities, new trends and different opinions in the treatment of bone diseases. Methods: Search, summarize and analyze the recent literature up to August 2007, related to osteoporosis and joint diseases. Results/conclusion: The drug discovery based on the molecular mechanism of bone remodeling has made some progress, but there are challenges, difficulties and different opinions. Bone resorption by osteoclasts is directly regulated by osteoblasts via the receptor activator of NF-κB/receptor activator of NF-κB ligand/osteoprotegerin signaling pathway, whereas the regulation of bone formation is poorly understood. Several aspects, including the present state and future trends, are commented as the expert opinions in this paper.