title: Legumain is activated in macrophages during pancreatitis.
abstract: Pancreatitis is an inflammatory disease of the pancreas characterized by dysregulated activity of digestive enzymes, necrosis, immune infiltration, and pain. Repeated incidence of pancreatitis is an important risk factor for pancreatic cancer. Legumain, a lysosomal cysteine protease, has been linked to inflammatory diseases such as atherosclerosis, stroke, and cancer. Until now, legumain activation has not been studied during pancreatitis. We used a fluorescently quenched activity-based probe to assess legumain activation during caerulein-induced pancreatitis in mice. We detected activated legumain by ex vivo imaging, confocal microscopy, and gel electrophoresis. Compared with healthy controls, legumain activity in the pancreas of caerulein-treated mice was increased in a time-dependent manner. Legumain was localized to CD68(+) macrophages and was not active in pancreatic acinar cells. Using a small-molecule inhibitor of legumain, we found that this protease is not essential for the initiation of pancreatitis. However, it may serve as a biomarker of disease, since patients with chronic pancreatitis show strongly increased legumain expression in macrophages. Moreover, the occurrence of legumain-expressing macrophages in regions of acinar-to-ductal metaplasia suggests that this protease may influence reprogramming events that lead to inflammation-induced pancreatic cancer.
authors: Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia; Laura.Edgington-Mitchell@monash.edu.
authors: Laura E
authors: LE
authors: Edgington-Mitchell
authors: Department of Surgery, Division of Experimental Surgery, Otto-von-Guericke University, Magdeburg, Germany;
authors: Thomas
authors: T
authors: Wartmann
authors: Department of Cancer Biology, Mayo Clinic Comprehensive Cancer Center, Mayo Clinic, Jacksonville, Florida;
authors: Alicia K
authors: AK
authors: Fleming
authors: Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, New York;
authors: Vasilena
authors: V
authors: Gocheva
authors: Department of Pathology, Stanford University School of Medicine, Stanford, California;
authors: Wouter A
authors: WA
authors: van der Linden
authors: Department of Pathology, Stanford University School of Medicine, Stanford, California;
authors: Nimali P
authors: NP
authors: Withana
authors: Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud UMC, Nijmegen, The Netherlands;
authors: Martijn
authors: M
authors: Verdoes
authors: Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia;
authors: Luigi
authors: L
authors: Aurelio
authors: Laboratory for Turbulence Research in Aerospace and Combustion, Department of Mechanical and Aerospace Engineering, Monash University, Melbourne, Victoria, Australia;
authors: Daniel
authors: D
authors: Edgington-Mitchell
authors: Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia;
authors: TinaMarie
authors: T
authors: Lieu
authors: Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia;
authors: Belinda S
authors: BS
authors: Parker
authors: Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia;
authors: Bim
authors: B
authors: Graham
authors: Institute of Molecular Medicine and Cell Research, Faculty of Medicine, University of Freiburg, Freiburg, Germany;
authors: Thomas
authors: T
authors: Reinheckel
authors: Department of Anatomy and Neuroscience, University of Melbourne and Florey Institute of Neuroscience and Mental Health, Parkville, Victoria Australia;
authors: John B
authors: JB
authors: Furness
authors: Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, New York;
authors: Johanna A
authors: JA
authors: Joyce
authors: Department of Cancer Biology, Mayo Clinic Comprehensive Cancer Center, Mayo Clinic, Jacksonville, Florida;
authors: Peter
authors: P
authors: Storz
authors: Department of Surgery, Division of Experimental Surgery, Otto-von-Guericke University, Magdeburg, Germany;
authors: Walter
authors: W
authors: Halangk
authors: Department of Pathology, Stanford University School of Medicine, Stanford, California;
authors: Matthew
authors: M
authors: Bogyo
authors: Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia; Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia; and ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, Victoria, Australia.
authors: Nigel W
authors: NW
authors: Bunnett
mesh_terms: D000818:Animals; D002108:Ceruletide / Q000633:toxicity; D003546:Cysteine Endopeptidases / Q000235:genetics / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D008264:Macrophages / Q000201:enzymology* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010195:Pancreatitis / Q000139:chemically induced / Q000201:enzymology*; D000099240:Asparaginyl Endopeptidase
chemical_list: D002108:Ceruletide; D003546:Cysteine Endopeptidases; D004791:Enzyme Inhibitors; D000099240:Asparaginyl Endopeptidase
keywords: activity-based probe; biomarker; cysteine cathepsin; inflammation; legumain; macrophage; pancreas; pancreatic cancer; pancreatitis