Cathepsin L in normal and pathological bone reodeling

Abstract Cathepsin L is a ubiquitous lysosomal cysteineendopeptidase that is mainly involved in the metabolicturnover of intracellular proteins. However, it is now wellestablished that this enzyme may also be implicated in theregulation of other important biological processes includ-ing bone resorption. Therefore, altered expression levels ofCathepsin L may result in disturbances of bone homeo-stasis and, eventually, in the onset of pathological condi-tions associated with altered bone turnover. Theseobservations support the concept that Cathepsin L may beregarded as an additional target for the development ofnovel therapeutic options for the treatment of patients withbone diseases. This review provides insight into the mostrecent advances in understanding the role of Cathepsin L innormal and pathological bone remodeling and discusses thepotential clinical and therapeutic applications related tothese findings.