title: Stimulation of intracellular Ca2+ elevation in neutrophils by thiol-oxidizing phenylarsine oxide.
abstract: Phenylarsine oxide (PAO), a trivalent arsenical compound, stimulated [Ca2+]i elevation in rat neutrophils in a Ca2+-containing medium but caused no appreciable response in a Ca2+-free medium. PAO also induced external Mn2+ entry, which was inhibited by N-acetyl-L-cysteine (NAC), but failed to elicit any appreciable Ba2+ and Sr2+ entry. Pretreatment of neutrophils with thiol-reducing agents including dithiothreitol (DTT), NAC, 2,3-dimercapto-1-propanol (DMP), 2,3-dimercaptopropane-1-sulfonic acid (DMPS) and tris-(2-carboxyethyl)phosphine (TCEP), all greatly inhibited PAO-induced [Ca2+]i elevation. Addition of Ni2+ or La3+ followed by PAO stimulation also attenuated the Ca2+ signals in a concentration-dependent manner. PAO had no significant effect on the production of reactive oxygen intermediates (ROI) and nitric oxide (NO) nor did it decrease cellular low molecular weight thiols levels. PAO-induced [Ca2+]i elevation was significantly inhibited by 1-[6-[17beta-3-methoxyestra-1,3,5(10)-trien-17-yl]amino]hexyl]-1H-pyrrole-2,5-dione (U-73122), the inhibitor of phospholipase C-coupled processes, genistein, a general tyrosine kinase inhibitor, phorbol 12-myristate 13-acetate (PMA), a protein kinase C (PKC) activator, calyculin A, a cortical actin stabilizer, 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one (LY 294002), a phosphoinositide 3-kinase inhibitor, 1-[beta-[3-(4-methoxyphenyl)propoxy]-4-methoxyphenethyl]-1H-imidazole (SKF-96365), and cis-N-(2-phenylcyclopentyl)azacyclotridec-1-en-2-amine (MDL-12,330A), the blockers of receptor-gated and store-operated Ca2+ channels, whereas there was no appreciable effect exerted by aristolochic acid, a phospholipase A2 inhibitor, 7-nitroindazole and N-(3-aminomethyl)benzylacetamidine (1400W), the blockers of NO synthase, and by suspension in a Na+-deprived medium. In contrast, 2-aminoethoxydiphenyl borane (2-APB), the blocker of IP3 receptor and Ca2+ influx, enhanced the PAO-induced response. PAO had no effect on the plasma membrane Ca2+-ATPase (PMCA) activity in the pharmacological isolated neutrophil preparation and the neutrophil membrane fractions. These results indicate that PAO stimulates [Ca2+]i rise in rat neutrophils mainly through the oxidation of vicinal thiol groups on the cell surface membrane to activation of a non-store operated Ca2+ entry (non-SOCE) without affecting the activity of PMCA and the plasmalemmal Na+/Ca2+ exchanger.
authors.affiliation: Department of Education and Research, Taichung Veterans General Hospital, Taichung, Taiwan, ROC. w1994@vghtc.gov.tw
authors.forename: Jih-Pyang
authors.initials: JP
authors.lastname: Wang
authors.forename: Jaw-Ji
authors.initials: JJ
authors.lastname: Tsai
authors.forename: Yu-San
authors.initials: YS
authors.lastname: Chen
authors.forename: Mei-Feng
authors.initials: MF
authors.lastname: Hsu
mesh_terms: D000818:Animals; D001012:Aorta, Abdominal / Q000166:cytology; D034341:Aristolochic Acids / Q000494:pharmacology; D001152:Arsenicals / Q000494:pharmacology*; D001464:Barium / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects; D000252:Calcium-Transporting ATPases / Q000032:analysis / Q000187:drug effects / Q000378:metabolism; D002219:Carbamates; D002462:Cell Membrane / Q000201:enzymology; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005663:Furans; D007191:Indazoles / Q000494:pharmacology; D007211:Indoles / Q000494:pharmacology; D008297:Male; D008345:Manganese / Q000378:metabolism; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors; D009504:Neutrophils / Q000187:drug effects* / Q000378:metabolism; D009569:Nitric Oxide / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000032:analysis / Q000378:metabolism; D013324:Strontium / Q000378:metabolism; D013449:Sulfonamides / Q000494:pharmacology
chemical_list: D034341:Aristolochic Acids; D001152:Arsenicals; D002219:Carbamates; D004791:Enzyme Inhibitors; D005663:Furans; D007191:Indazoles; D007211:Indoles; D017382:Reactive Oxygen Species; D013449:Sulfonamides; C029341:oxophenylarsine; D001464:Barium; D009569:Nitric Oxide; D008345:Manganese; C095108:amprenavir; C000228:aristolochic acid I; D019255:NADPH Oxidases; D000252:Calcium-Transporting ATPases; D002118:Calcium; C080122:7-nitroindazole; C000543:cyclopiazonic acid; D013324:Strontium