Upregulation of cathepsin S in psoriatic keratinocytes.

Cathepsin S (CATS) is a cysteine protease, well known for its role in MHC class II-mediated antigen presentation and extracellular matrix degradation. Disturbance of the expression or metabolism of this protease is a concomitant feature of several diseases. Given this importance we studied the localization and regulation of CATS expression in normal and pathological human/mouse skin.

Intra- versus extracellular effects of microglia-derived cysteine proteases in a conditioned medium transfer model.

Activated microglia release inflammatory mediators that display either beneficial or harmful effects on neuronal survival and signaling. In the present study we demonstrate that exposure to lipopolysaccharide leads to an increase in the lysosomal cysteine proteases, cathepsin B, K, S, and X, in culture supernatants of the microglia cell line BV-2. In addition, we observed an up-regulation of cathepsins in the cytoplasmic fraction in response to stimulation with lipopolysaccharide.