Figure 1
From: Activation of Proteinase 3 Contributes to Nonalcoholic Fatty Liver Disease and Insulin Resistance
The role of neutrophil serine proteases in inflammation. Following activation, neutrophils will release their serine proteases in the extracellular environment. A portion of these released serine proteases will bind to the membrane. Once released, serine proteases (both membrane-bound and in the extracellular environment) are able to process (activate and/or inactivate) cytokines, thereby regulating inflammation. Human α-1 antitrypsin has potent anti-inflammatory properties. It complexes with proteinase 3, neutrophil elastase and cathepsin G, thereby preventing their enzymatic activities. It also inhibits caspase-1 and enhances the production of the anti-inflammatory mediators IL-10 and IL-1-Ra. All these actions result in a strong anti-inflammatory effect. PR3, proteinase 3; NE, neutrophil elastase; CG, cathepsin G; Casp-1, caspase-1; IL-1Ra, interleukin 1 receptor antagonist.