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Gut 62:430-439 doi:10.1136/gutjnl-2011-300771
  • Pancreas
  • Original article

Tumour necrosis factor α secretion induces protease activation and acinar cell necrosis in acute experimental pancreatitis in mice

  1. Julia Mayerle1
  1. 1Department of Medicine A, Ernst-Moritz-Arndt-University Greifswald, Greifswald, Germany
  2. 2Division of Medical Biology, Institute of Pathology, University of Rostock, Rostock, Germany
  3. 3Division of Experimental Surgery, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
  4. 4Department of Dermatology and Allergology, University of Ulm, Ulm, Germany
  5. 5Department of Cell Biology and Immunology, Vrije Universiteit, Amsterdam, The Netherlands
  1. Correspondence to Professor Julia Mayerle, Department of Medicine A, University Medicine, Ernst-Moritz-Arndt-University, Greifswald, Friedrich-Loeffler-Str. 23a, 17475 Greifswald, Germany; mayerle{at}uni-greifswald.de
  1. Contributors MS was involved in the acquisition of the data, analysis and interpretation of the data and drafting of the manuscript. AD and BK were involved in the acquisition of the data, analysis and interpretation of the data and critical revision of the manuscript. SRM and AA were involved in the acquisition of the data and critical revision of the manuscript. FUW was involved in technical support and critical revision of the manuscript for important intellectual content. TW was involved in technical support and critical revision of the manuscript for important intellectual content. KS-K was involved in technical and material support, critical revision of the manuscript for important intellectual content. NvR was involved in technical and material support. WH was involved in technical support and critical revision of the manuscript for important intellectual content. MML was responsible for study concept and design, drafting of the manuscript, obtaining funding and study supervision. JM was responsible for study concept and design, drafting of the manuscript, obtaining funding and study supervision.

  • Revised 17 January 2012
  • Accepted 28 January 2012
  • Published Online First 5 April 2012

Abstract

Background Acute pancreatitis has long been considered a disorder of pancreatic self-digestion, in which intracellular activation of digestive proteases induces tissue injury. Chemokines, released from damaged pancreatic cells then attract inflammatory cells, whose systemic action ultimately determines the disease severity. In the present work the opposite mechanism is investigated; that is, whether and how inflammatory cells can activate intracellular proteases.

Design Using mice either deficient for the CD18-α subunit of the membrane attack complex-1 (MAC-1) complex or tumour necrosis factor (TNF)α, as well as after depletion of leucocyte subpopulations, pancreatitis was induced by 7-hourly caerulein injections (50 μg/kg, intraperitoneally). Pancreatic acini were coincubated in vitro from wild-type and cathepsin-B-deficient animals with phorbol-12-myristate-13-acetate (PMA)-activated neutrophils and macrophages, caerulein or TNFα, and activities of trypsin, cathepsin-B and caspase-3 were measured, as well as necrosis using fluorogenic substrates. TNFα was inhibited with monospecific antibodies.

Results Deletion of CD18 prevented transmigration of leucocytes into the pancreas during pancreatitis, greatly reduced disease severity and abolished digestive protease activation. Depletion of neutrophils and macrophages equally reduced premature trypsinogen activation and disease severity. In vitro activated neutrophils and macrophages directly induced premature protease activation and cell death in pancreatic acini and stimulation of acini with TNFα induced caspase-3 activation and necrosis via a cathepsin-B and calcium-dependent mechanism. Neutralising antibodies against TNFα and genetic deletion of TNFα prevented leucocyte-induced trypsin activity and necrosis in isolated acini.

Conclusions The soluble inflammatory cell mediator TNFα directly induces premature protease activation and necrosis in pancreatic acinar cells. This activation depends on calcium and cathepsin-B activity. The findings from the present work further suggest that targeting TNFα, for which pharmaceutical agents are readily available, could be an effective treatment strategy that directly addresses the cellular causes of pancreatitis.

Footnotes

  • MML and JM contributed equally to the study.

  • Funding Supported by the Alfried-Krupp-von-Bohlen-und-Hahlbach-Foundation (Graduate Schools Tumour Biology and Free Radical Biology), the Deutsche Krebshilfe/Dr Mildred-Scheel-Stiftung (109102), the Deutsche Forschungsgemeinschaft (DFG GRK840-E3/E4, MA 4115/1-2/3, NI 1297/1-1), the Federal Ministry of Education and Research (BMBF GANI-MED 03152061A and BMBF 0314107) and the European Union (EU-FP-7: EPC-TM and EU-FP7-REGPOT-2010-1).

  • Competing interests None.

  • Provenance and peer review Not commissioned; externally peer reviewed.