title: Auranofin modulated cytoplasmic free calcium in neutrophils by mobilizing intracellular calcium and inhibiting protein kinase.
abstract: The effect of the lipophilic gold compound, auranofin (AUR) on the calcium homeostasis of human neutrophils treated with or without n-formyl-methionyl-leucyl-phenylalanine (FMLP) was investigated. In agreement with previous reports, FMLP induced a rapid release of intracellular Ca2+ stores followed by a smaller influx of extracellular Ca2+. AUR and staurosporine enhanced while phorbol 12-myristate 13-acetate suppressed the secondary influx of Ca2+. Mn2(+)-quenching-of-fluorescence studies indicate that phorbol 12-myristate 13-acetate incubation blocked cation entry. AUR or staurosporine potentiation of FMLP effects on cytoplasmic free Ca2+ [( Ca2+]i) was attributed to suppression of negative feedback effects of protein kinase C. AUR (5-45 microM) per se induced a slow release of internal Ca2+ stores followed by a delayed influx of extracellular Ca2+. Control studies showed that AUR did not induce the formation of inositol 1,4,5-trisphosphate, lyse cells, or promote dye leakage. Dithiothreitol suppressed the AUR effect. AUR triggered biphasic but smaller increases in [Ca2+]i of neutrophil cytoplasts. Studies with permeabilized neutrophils showed that AUR directly released Ca2+ from internal stores. By comparison, gold sodium thiomalate, which had no effect on intact cells, also released Ca2+ from permeabilized cells. Present results indicate that AUR modulated [Ca2+]i directly by mobilized Ca2+ from multiple storage sites and indirectly by inhibiting protein kinase C.
authors: Department of Medicine, University of Alberta, Edmonton, Canada.
authors: K
authors: K
authors: Wong
authors: J
authors: J
authors: Parente
authors: K V
authors: KV
authors: Prasad
authors: D
authors: D
authors: Ng
mesh_terms: D001310:Auranofin / Q000494:pharmacology*; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D002451:Cell Compartmentation / Q000187:drug effects; D003593:Cytoplasm / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005453:Fluorescence; D006052:Gold Sodium Thiomalate / Q000494:pharmacology; D006706:Homeostasis / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D008345:Manganese / Q000494:pharmacology; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000378:metabolism*; D011493:Protein Kinase C / Q000037:antagonists & inhibitors*; D015398:Signal Transduction; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D006052:Gold Sodium Thiomalate; D001310:Auranofin; D008345:Manganese; D009240:N-Formylmethionine Leucyl-Phenylalanine; D015544:Inositol 1,4,5-Trisphosphate; D011493:Protein Kinase C; D017301:Ca(2+) Mg(2+)-ATPase; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium