Calcium-sensing soluble adenylyl cyclase mediates TNF signal transduction in human neutrophils

• Published in: The Journal of experimental medicine Vol. 202; no. 3; pp. 353 - 361
• Main Authors: Han, Hyunsil, Stessin, Alexander, Roberts, Julia, Hess, Kenneth, Gautam, Narinder, Kamenetsky, Margarita, Lou, Olivia, Hyde, Edward, Nathan, Noah, Muller, William A, Buck, Jochen, Levin, Lonny R, Nathan, Carl
• Format: Journal Article
• Language: English
• Published: United States The Rockefeller University Press 01-08-2005
• Subjects: Adenylyl Cyclases - metabolism; Anti-Inflammatory Agents, Non-Steroidal - pharmacology; Brief Definitive Report; Calcium Signaling - drug effects; Calcium Signaling - physiology; Cell Degranulation - drug effects; Cell Degranulation - physiology; Cells, Cultured; Cyclic AMP - metabolism; Enzyme Activation - drug effects; Humans; Inflammation - metabolism; Neutrophil Activation - drug effects; Neutrophil Activation - physiology; Neutrophils - cytology; Neutrophils - metabolism; Oxidoreductases - metabolism; Pyrazolones - pharmacology; rap1 GTP-Binding Proteins - metabolism; Receptors, Calcium-Sensing - metabolism; Tumor Necrosis Factor-alpha - metabolism; Tumor Necrosis Factor-alpha - pharmacology
• ISSN: 0022-1007; 1540-9538; 1892-1007
• DOI: 10.1084/jem.20050778

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.