Rupjyoti Talukdar1, Archana Sareen2, Hongyan Zhu2, Zuobiao Yuan2, Ajay Dixit3, Hassam Cheema3, John George3, Usman Barlass2, Raghuwansh Sah4, Sushil K Garg2, Sulagna Banerjee3, Pramod Garg5, Vikas Dudeja3, Rajinder Dawra3, Ashok K Saluja6. 1. Department of Gastroenterology, Asian Institute of Gastroenterology, Hyderabad, India. 2. Department of Surgery, University of Minnesota, Minneapolis, Minnesota. 3. Department of Surgery, University of Miami, Miller School of Medicine, Miami, Florida. 4. Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota. 5. Department of Gastroenterology, All India Institute of Medical Sciences, New Delhi, India. 6. Department of Surgery, University of Miami, Miller School of Medicine, Miami, Florida. Electronic address: asaluja@miami.edu.
Abstract
BACKGROUND & AIMS: Experimental studies in acute pancreatitis (AP) suggest a strong association of acinar cell injury with cathepsin B-dependent intracellular activation of trypsin. However, the molecular events subsequent to trypsin activation and their role, if any, in cell death is not clear. In this study, we have explored intra-acinar events downstream of trypsin activation that lead to acinar cell death. METHODS: Acinar cells prepared from the pancreas of rats or mice (wild-type, trypsinogen 7, or cathepsin B-deleted) were stimulated with supramaximal cerulein, and the cytosolic activity of cathepsin B and trypsin was evaluated. Permeabilized acini were used to understand the differential role of cytosolic trypsin vs cytosolic cathepsin B in activation of apoptosis. Cell death was evaluated by measuring specific markers for apoptosis and necrosis. RESULTS: Both in vitro and in vivo studies have suggested that during AP cathepsin B leaks into the cytosol from co-localized organelles, through a mechanism dependent on active trypsin. Cytosolic cathepsin B but not trypsin activates the intrinsic pathway of apoptosis through cleavage of bid and activation of bax. Finally, excessive release of cathepsin B into the cytosol can lead to cell death through necrosis. CONCLUSIONS: This report defines the role of trypsin in AP and shows that cytosolic cathepsin B but not trypsin activates cell death pathways. This report also suggests that trypsin is a requisite for AP only because it causes release of cathepsin B into the cytosol.
BACKGROUND & AIMS: Experimental studies in acute pancreatitis (AP) suggest a strong association of acinar cell injury with cathepsin B-dependent intracellular activation of trypsin. However, the molecular events subsequent to trypsin activation and their role, if any, in cell death is not clear. In this study, we have explored intra-acinar events downstream of trypsin activation that lead to acinar cell death. METHODS: Acinar cells prepared from the pancreas of rats or mice (wild-type, trypsinogen 7, or cathepsin B-deleted) were stimulated with supramaximal cerulein, and the cytosolic activity of cathepsin B and trypsin was evaluated. Permeabilized acini were used to understand the differential role of cytosolic trypsin vs cytosolic cathepsin B in activation of apoptosis. Cell death was evaluated by measuring specific markers for apoptosis and necrosis. RESULTS: Both in vitro and in vivo studies have suggested that during AP cathepsin B leaks into the cytosol from co-localized organelles, through a mechanism dependent on active trypsin. Cytosolic cathepsin B but not trypsin activates the intrinsic pathway of apoptosis through cleavage of bid and activation of bax. Finally, excessive release of cathepsin B into the cytosol can lead to cell death through necrosis. CONCLUSIONS: This report defines the role of trypsin in AP and shows that cytosolic cathepsin B but not trypsin activates cell death pathways. This report also suggests that trypsin is a requisite for AP only because it causes release of cathepsin B into the cytosol.
Authors: V P Singh; A K Saluja; L Bhagat; G J van Acker; A M Song; S P Soltoff; L C Cantley; M L Steer Journal: J Clin Invest Date: 2001-11 Impact factor: 14.808
Authors: Sebastian Gaiser; Jaroslaw Daniluk; Yan Liu; Lilian Tsou; Jun Chu; Woojin Lee; Daniel S Longnecker; Craig D Logsdon; Baoan Ji Journal: Gut Date: 2011-04-06 Impact factor: 23.059
Authors: Ali A Aghdassi; Daniel S John; Matthias Sendler; F Ulrich Weiss; Thomas Reinheckel; Julia Mayerle; Markus M Lerch Journal: J Biol Chem Date: 2017-12-11 Impact factor: 5.157
Authors: Subhankar Dolai; Tao Liang; Abrahim I Orabi; Li Xie; Douglas Holmyard; Tanveer A Javed; Nestor A Fernandez; Huanli Xie; Mark S Cattral; Debbie C Thurmond; Peter Thorn; Herbert Y Gaisano Journal: J Biol Chem Date: 2017-12-28 Impact factor: 5.157
Authors: Julia Mayerle; Matthias Sendler; Eszter Hegyi; Georg Beyer; Markus M Lerch; Miklós Sahin-Tóth Journal: Gastroenterology Date: 2019-01-18 Impact factor: 22.682
Authors: Subhankar Dolai; Toshimasa Takahashi; Tairan Qin; Tao Liang; Li Xie; Fei Kang; Yi-Fan Miao; Huanli Xie; Youhou Kang; Justin Manuel; Erin Winter; Paul A Roche; Mark S Cattral; Herbert Y Gaisano Journal: Autophagy Date: 2020-12-07 Impact factor: 16.016