From furless to heartless—unraveling the diverse functions of cathepsin L.

Cathepsin L in Normal and Pathological Bone Remodeling

“…Although Cathepsin L appears to be primarily a ''housekeeping enzyme,'' several studies indicate that it may harbor important functions outside of lysosomes. Compelling evidence, in this regard, shows that the enzyme also appears to be implicated in the regulation of other important biological processes such as apoptosis and tissue homeostasis [15,[34][35][36][37], immune response [15,[38][39][40], hormone production and processing [41,42] and activation of latent forms of other proteolytic enzymes [6,15,[43][44][45]. Interestingly, growing evidence suggests that Cathepsin L may also have a role in the regulation of bone resorption in normal and pathological conditions [6,15,35,[46][47][48][49][50][51].…”

Cathepsin L in metastatic bone disease: therapeutic implications

“…The intracellular activity of these proteinases is regulated by endogenous inhibitors of the cystastins superfamily . However, the biological functions of cathepsin L are not merely confined to the breakdown of intracellular proteins but also comprise other important processes such as apoptosis and tissue homeostasis (Hagemann et al, 2004;Potts et al, 2004;Stoka et al, 2007;Luft, 2009;Dennemärker et al, 2010;Lankelma et al, 2010), immune response (Hsing and Rudensky, 2005;Zavasnik-Bergant and Turk, 2007), activation of latent forms of other proteolytic enzymes (Everts et al, 2006;Laurent-Matha et al, 2006;Abboud-Jarrous et al, 2008) and hormone production and processing (Yasothornsrikul et al, 2003;Funkelstein et al, 2008). The active role of cathepsin L in some of these processes is further confirmed by in vivo studies which show that cathepsin L-deficient mice exhibit distinct defects in MHC class II processing in thymic cortical epithelial cells, impaired myocardial functions, epithelial hyperplasia, hypotrichosis and…”

“…References progressive hair loss (Reinheckel et al, 2001;Hagemann et al, 2004;Potts et al, 2004;Luft, 2009) and reduced production and secretion of neurotransmitters and hormones (Yasothornsrikul et al, 2003;Funkelstein et al, 2008).…”