Inflammation cathepsins

CA C1 C01.034 Cathepsin S Tissue damage associated with inflammation... 

Eosinophils may be increased in some patients, particularly during exacerbations. Activated inflammatory cells release a variety of mediators, most notably leukotriene B4, interleukin-8, and tumor necrosis factor-a (TNF-a). Various proteinases, such as elastase, cathepsin G, and proteinase-3, are secreted by activated neutrophils. These mediators and proteinases are capable of sustaining inflammation and damaging lung structures. 

The two distinct types of mast cells in humans are distinguished by differences in their secretory granule protease constituents. cells contain chy-mase, carboxypeptidase, cathepsin G-like protease and tryptase. They are the predominant type of mast cells found in the skin and in the gastrointestinal submucosa. MC.p cells contain only tryptase and are the predominant type of mast cell found in the lung, particularly in the alveoli, and in the small intestinal mucosa (37,38). Although one of these mast cell types often predominates in a given tissue, smaller amounts of the other mast cell type are also usually present. In addition, the relative amount of each type of mast cell within the tissue may change with tissue inflammation or fibrosis (39). 

In addition to activated macroautophagy, our studies provided important evidence that autophagy related to lysosomal function is impaired in s-IBM muscle fibers. They showed a decrease of lysosomal cathepsin D and B enzymatic activities that appeared spedfic to s-IBM, because in polymyositis muscle fibers their activities were actually increased in our study [13] and in studies by others (referenced in [13]). In polymyositis macroautophagy was also increased but autophagic vacuoles and indusions do not form, perhaps because the lysosomal system may be functioning adequately. Our results also suggest that lymphocytic inflammation, which is... 

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