Mechanisms of bone resorption

Resorption of mineralized tissues like bone is accomplished by a unique cell type: the osteoclast. This multinucleated cell has the capacity to dissolve the mineral by lowering the pH. Subsequently, the release of certain proteolytic enzymes, in particular cathepsin K, results in the digestion of the organic matrix mainly consisting of collagen. In this short review we will describe the unique features of the osteoclast making it possible for the cell to resorb mineralized tissues.