title: The role of Ca2+ influx in endocytic vacuole formation in pancreatic acinar cells.
abstract: The inducers of acute pancreatitis trigger a prolonged increase in the cytosolic Ca(2+) concentration ([Ca(2+)]c), which is responsible for the damage to and eventual death of pancreatic acinar cells. Vacuolization is an important indicator of pancreatic acinar cell damage. Furthermore, activation of trypsinogen occurs in the endocytic vacuoles; therefore the vacuoles can be considered as 'initiating' organelles in the development of the cell injury. In the present study, we investigated the relationship between the formation of endocytic vacuoles and Ca(2+) influx developed in response to the inducers of acute pancreatitis [bile acid taurolithocholic acid 3-sulfate (TLC-S) and supramaximal concentration of cholecystokinin-8 (CCK)]. We found that the inhibitor of STIM (stromal interaction molecule)/Orai channels, GSK-7975A, effectively suppressed both the Ca(2+) influx (stimulated by inducers of pancreatitis) and the formation of endocytic vacuoles. Cell death induced by TLC-S or CCK was also inhibited by GSK-7975A. We documented the formation of endocytic vacuoles in response to store-operated Ca(2+) entry (SOCE) induced by thapsigargin [TG; inhibitor of sarcoplasmic/endoplasmic reticulum (ER) Ca(2+) pumps] and observed strong inhibition of TG-induced vacuole formation by GSK-7975A. Finally, we found that structurally-unrelated inhibitors of calpain suppress formation of endocytic vacuoles, suggesting that this Ca2+-dependent protease is a mediator between Ca(2+) elevation and endocytic vacuole formation.
authors.affiliation: *Department of Cellular and Molecular Physiology, University of Liverpool, Crown Street, Liverpool L69 3BX, U.K.
authors.forename: Svetlana
authors.initials: S
authors.lastname: Voronina
authors.affiliation: *Department of Cellular and Molecular Physiology, University of Liverpool, Crown Street, Liverpool L69 3BX, U.K.
authors.forename: David
authors.initials: D
authors.lastname: Collier
authors.affiliation: *Department of Cellular and Molecular Physiology, University of Liverpool, Crown Street, Liverpool L69 3BX, U.K.
authors.forename: Michael
authors.initials: M
authors.lastname: Chvanov
authors.affiliation: *Department of Cellular and Molecular Physiology, University of Liverpool, Crown Street, Liverpool L69 3BX, U.K.
authors.forename: Ben
authors.initials: B
authors.lastname: Middlehurst
authors.affiliation: *Department of Cellular and Molecular Physiology, University of Liverpool, Crown Street, Liverpool L69 3BX, U.K.
authors.forename: Alison J
authors.initials: AJ
authors.lastname: Beckett
authors.affiliation: *Department of Cellular and Molecular Physiology, University of Liverpool, Crown Street, Liverpool L69 3BX, U.K.
authors.forename: Ian A
authors.initials: IA
authors.lastname: Prior
authors.affiliation: *Department of Cellular and Molecular Physiology, University of Liverpool, Crown Street, Liverpool L69 3BX, U.K.
authors.forename: David N
authors.initials: DN
authors.lastname: Criddle
authors.affiliation: ‡Respiratory Therapy Area Unit, Medicines Research Centre, GlaxoSmithKline, Stevenage SG1 2NY, England, U.K.
authors.forename: Malcolm
authors.initials: M
authors.lastname: Begg
authors.affiliation: †Laboratory for Developmental Neurobiology, Riken Brain Science Institute, 2-1 Hirosawa, Wako City, Saitama 351-0198, Japan.
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Mikoshiba
authors.affiliation: §NIHR Liverpool Pancreas Biomedical Research Unit, University of Liverpool, Crown Street, Liverpool L69 3BX, U.K.
authors.forename: Robert
authors.initials: R
authors.lastname: Sutton
authors.affiliation: *Department of Cellular and Molecular Physiology, University of Liverpool, Crown Street, Liverpool L69 3BX, U.K.
authors.forename: Alexei V
authors.initials: AV
authors.lastname: Tepikin
mesh_terms: D061354:Acinar Cells / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D051379:Mice; D010179:Pancreas / Q000166:cytology* / Q000378:metabolism*; D022161:Transport Vesicles / Q000378:metabolism*; D014617:Vacuoles / Q000378:metabolism*
chemical_list: D002118:Calcium