fig1

Figure 1. Roles of lysosomal and neutrophil serine proteases in acute pancreatitis. The conversion of trypsinogen into its active form is an important step in the early phase of acute pancreatitis. In addition to autoactivation, trypsinogen is activated by cathepsin B (CTSB) derived from acini and macrophages. Pro-CTSB itself is proteolytically activated by cathepsin D (CTSD). While cathepsin C (CTSC) does not directly act on trypsinogen, it activates the neutrophil serine proteases cathepsin G (CTSG), proteinase 3 (PR3), and neutrophil elastase (NE). NE readily cleaves the cell-adhesion molecule E-cadherin, leading to the dissociation of acini.