title: Ca2+ release-activated Ca2+ channel blockade as a potential tool in antipancreatitis therapy.
abstract: Alcohol-related acute pancreatitis can be mediated by a combination of alcohol and fatty acids (fatty acid ethyl esters) and is initiated by a sustained elevation of the Ca(2+) concentration inside pancreatic acinar cells ([Ca(2+)]i), due to excessive release of Ca(2+) stored inside the cells followed by Ca(2+) entry from the interstitial fluid. The sustained [Ca(2+)]i elevation activates intracellular digestive proenzymes resulting in necrosis and inflammation. We tested the hypothesis that pharmacological blockade of store-operated or Ca(2+) release-activated Ca(2+) channels (CRAC) would prevent sustained elevation of [Ca(2+)]i and therefore protease activation and necrosis. In isolated mouse pancreatic acinar cells, CRAC channels were activated by blocking Ca(2+) ATPase pumps in the endoplasmic reticulum with thapsigargin in the absence of external Ca(2+). Ca(2+) entry then occurred upon admission of Ca(2+) to the extracellular solution. The CRAC channel blocker developed by GlaxoSmithKline, GSK-7975A, inhibited store-operated Ca(2+) entry in a concentration-dependent manner within the range of 1 to 50 μM (IC50 = 3.4 μM), but had little or no effect on the physiological Ca(2+) spiking evoked by acetylcholine or cholecystokinin. Palmitoleic acid ethyl ester (100 μM), an important mediator of alcohol-related pancreatitis, evoked a sustained elevation of [Ca(2+)]i, which was markedly reduced by CRAC blockade. Importantly, the palmitoleic acid ethyl ester-induced trypsin and protease activity as well as necrosis were almost abolished by blocking CRAC channels. There is currently no specific treatment of pancreatitis, but our data show that pharmacological CRAC blockade is highly effective against toxic [Ca(2+)]i elevation, necrosis, and trypsin/protease activity and therefore has potential to effectively treat pancreatitis.
authors.affiliation: Medical Research Council Group, Cardiff School of Biosciences, Cardiff University, Cardiff CF10 3AX Wales, United Kingdom.
authors.forename: Julia V
authors.initials: JV
authors.lastname: Gerasimenko
authors.forename: Oleksiy
authors.initials: O
authors.lastname: Gryshchenko
authors.forename: Pawel E
authors.initials: PE
authors.lastname: Ferdek
authors.forename: Eloise
authors.initials: E
authors.lastname: Stapleton
authors.forename: Tania O G
authors.initials: TO
authors.lastname: Hébert
authors.forename: Solomiia
authors.initials: S
authors.lastname: Bychkova
authors.forename: Shuang
authors.initials: S
authors.lastname: Peng
authors.forename: Malcolm
authors.initials: M
authors.lastname: Begg
authors.forename: Oleg V
authors.initials: OV
authors.lastname: Gerasimenko
authors.forename: Ole H
authors.initials: OH
authors.lastname: Petersen
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D061354:Acinar Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D001464:Barium / Q000378:metabolism; D001549:Benzamides / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D015220:Calcium Channels / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D005229:Fatty Acids, Monounsaturated / Q000494:pharmacology; D022781:Hepatocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D015640:Ion Channel Gating / Q000187:drug effects*; D017136:Ion Transport / Q000187:drug effects; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice; D000071740:ORAI1 Protein; D000071741:ORAI2 Protein; D010179:Pancreas / Q000166:cytology; D019512:Pancreatitis, Alcoholic / Q000188:drug therapy* / Q000378:metabolism; D018408:Patch-Clamp Techniques; D011720:Pyrazoles / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: C583716:2,6-difluoro-N-(1-(4-hydroxy-2-(trifluoromethyl)benzyl)-1H-pyrazol-3-yl)benzamide; D001549:Benzamides; D002121:Calcium Channel Blockers; D015220:Calcium Channels; D005229:Fatty Acids, Monounsaturated; D000071740:ORAI1 Protein; D000071741:ORAI2 Protein; C520430:Orai1 protein, mouse; C520431:Orai2 protein, mouse; D011720:Pyrazoles; D014665:Vasodilator Agents; C008757:palmitoleic acid; D001464:Barium; D000109:Acetylcholine; D002118:Calcium
keywords: AR42J; alcohol metabolite; capacitative Ca2+ entry; hepatocyte Ca2+ entry; pancreas