title: Calcium-sensing soluble adenylyl cyclase mediates TNF signal transduction in human neutrophils.
abstract: Through chemical screening, we identified a pyrazolone that reversibly blocked the activation of phagocyte oxidase (phox) in human neutrophils in response to tumor necrosis factor (TNF) or formylated peptide. The pyrazolone spared activation of phox by phorbol ester or bacteria, bacterial killing, TNF-induced granule exocytosis and phox assembly, and endothelial transmigration. We traced the pyrazolone's mechanism of action to inhibition of TNF-induced intracellular Ca2+ elevations, and identified a nontransmembrane ("soluble") adenylyl cyclase (sAC) in neutrophils as a Ca2+-sensing source of cAMP. A sAC inhibitor mimicked the pyrazolone's effect on phox. Both compounds blocked TNF-induced activation of Rap1A, a phox-associated guanosine triphosphatase that is regulated by cAMP. Thus, TNF turns on phox through a Ca2+-triggered, sAC-dependent process that may involve activation of Rap1A. This pathway may offer opportunities to suppress oxidative damage during inflammation without blocking antimicrobial function.
authors.affiliation: Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, NY 10021, USA.
authors.forename: Hyunsil
authors.initials: H
authors.lastname: Han
authors.forename: Alexander
authors.initials: A
authors.lastname: Stessin
authors.forename: Julia
authors.initials: J
authors.lastname: Roberts
authors.forename: Kenneth
authors.initials: K
authors.lastname: Hess
authors.forename: Narinder
authors.initials: N
authors.lastname: Gautam
authors.forename: Margarita
authors.initials: M
authors.lastname: Kamenetsky
authors.forename: Olivia
authors.initials: O
authors.lastname: Lou
authors.forename: Edward
authors.initials: E
authors.lastname: Hyde
authors.forename: Noah
authors.initials: N
authors.lastname: Nathan
authors.forename: William A
authors.initials: WA
authors.lastname: Muller
authors.forename: Jochen
authors.initials: J
authors.lastname: Buck
authors.forename: Lonny R
authors.initials: LR
authors.lastname: Levin
authors.forename: Carl
authors.initials: C
authors.lastname: Nathan
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism*; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D020013:Calcium Signaling / Q000187:drug effects* / Q000502:physiology; D015550:Cell Degranulation / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D007249:Inflammation / Q000378:metabolism; D018375:Neutrophil Activation / Q000187:drug effects* / Q000502:physiology; D009504:Neutrophils / Q000166:cytology / Q000378:metabolism*; D010088:Oxidoreductases / Q000378:metabolism; D047069:Pyrazolones / Q000494:pharmacology; D044169:Receptors, Calcium-Sensing / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism / Q000494:pharmacology*; D020827:rap1 GTP-Binding Proteins / Q000378:metabolism
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D047069:Pyrazolones; C430803:RAP1A protein, human; D044169:Receptors, Calcium-Sensing; D014409:Tumor Necrosis Factor-alpha; C038362:pyrazolone; D000242:Cyclic AMP; D010088:Oxidoreductases; D020827:rap1 GTP-Binding Proteins; D000262:Adenylyl Cyclases