[The role of osteoclastic bone resorption on bone remodeling.]

Bone remodeling consists of bone resorbing cycle and bone forming cycle to maintain bone volume and calcium homeostasis thought life. The main cells involves in bone remodeling are osteoclasts and osteoblasts. Bone resorption and bone formation are tightly coupled during bone remodeling, an imbalance of these two processes leads to either increased or decreased bone mass. Osteoclasts are multinucleated cells responsible for physiological and pathological bone resorption and thereby play an essential role in maintaining bone volume and homeostasis. Osteoclastic bone resorption is regulated by several cytokines, calcium signal, and transcription factors etc. Recent molecular dissection of genetic disorders of high increased or decreased bone mass has proven many of the crucial molecules controlling the osteoclastic bone resorption. This article reviews recent findings of molecular mechanism regarding to osteoclastic bone resorption to regulate bone remodeling.