title: Ethanol and Other Short-Chain Alcohols Inhibit NLRP3 Inflammasome Activation through Protein Tyrosine Phosphatase Stimulation.
abstract: Immunosuppression is a major complication of alcoholism that contributes to increased rates of opportunistic infections and sepsis in alcoholics. The NLRP3 inflammasome, a multiprotein intracellular pattern recognition receptor complex that facilitates the cleavage and secretion of the proinflammatory cytokines IL-1β and IL-18, can be inhibited by ethanol, and we sought to better understand the mechanism through which this occurs and whether chemically similar molecules exert comparable effects. We show that ethanol can specifically inhibit activation of the NLRP3 inflammasome, resulting in attenuated IL-1β and caspase-1 cleavage and secretion, as well as diminished apoptosis-associated speck-like protein containing a CARD (ASC) speck formation, without affecting potassium efflux, in a mouse macrophage cell line (J774), mouse bone marrow-derived dendritic cells, mouse neutrophils, and human PBMCs. The inhibitory effects on the Nlrp3 inflammasome were independent of γ-aminobutyric acid A receptor activation or N-methyl-d-asparate receptor inhibition but were associated with decreased oxidant production. Ethanol treatment markedly decreased cellular tyrosine phosphorylation, whereas administration of the tyrosine phosphatase inhibitor sodium orthovanadate prior to ethanol restored tyrosine phosphorylation and IL-1β secretion subsequent to ATP stimulation. Furthermore, sodium orthovanadate-induced phosphorylation of ASC Y144, necessary and sufficient for Nlrp3 inflammasome activation, and secretion of phosphorylated ASC were inhibited by ethanol. Finally, multiple alcohol-containing organic compounds exerted inhibitory effects on the Nlrp3 inflammasome, whereas 2-methylbutane (isopentane), the analogous alkane of the potent inhibitor isoamyl alcohol (isopentanol), did not. Our results demonstrate that ethanol antagonizes the NLRP3 inflammasome at an apical event in its activation through the stimulation of protein tyrosine phosphatases, an effect shared by other short-chain alcohols.
authors.affiliation: Vermont Lung Center, Division of Pulmonary Disease and Critical Care, Department of Medicine, University of Vermont, Burlington, VT 05405;
authors.forename: Laura R
authors.initials: LR
authors.lastname: Hoyt
authors.affiliation: Vermont Lung Center, Division of Pulmonary Disease and Critical Care, Department of Medicine, University of Vermont, Burlington, VT 05405;
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Ather
authors.affiliation: Vermont Lung Center, Division of Pulmonary Disease and Critical Care, Department of Medicine, University of Vermont, Burlington, VT 05405;
authors.forename: Matthew J
authors.identifier: 0000-0003-3840-8952
authors.initials: MJ
authors.lastname: Randall
authors.affiliation: Department of Chemistry, University of Vermont, Burlington, VT 05405;
authors.forename: Daniel P
authors.identifier: 0000-0003-1191-3182
authors.initials: DP
authors.lastname: DePuccio
authors.affiliation: Department of Chemistry, University of Vermont, Burlington, VT 05405; Cellular, Molecular, and Biomedical Sciences Graduate Program, University of Vermont, Burlington, VT 05405; and.
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Landry
authors.affiliation: Pulmonary, Allergy, Critical Care and Sleep Medicine, The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University, Columbus, OH 43210.
authors.forename: Mark D
authors.identifier: 0000-0002-7079-5633
authors.initials: MD
authors.lastname: Wewers
authors.affiliation: Pulmonary, Allergy, Critical Care and Sleep Medicine, The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University, Columbus, OH 43210.
authors.forename: Mikhail A
authors.identifier: 0000-0003-2003-768X
authors.initials: MA
authors.lastname: Gavrilin
authors.affiliation: Vermont Lung Center, Division of Pulmonary Disease and Critical Care, Department of Medicine, University of Vermont, Burlington, VT 05405; Cellular, Molecular, and Biomedical Sciences Graduate Program, University of Vermont, Burlington, VT 05405; and matthew.poynter@uvm.edu.
authors.forename: Matthew E
authors.initials: ME
authors.lastname: Poynter
mesh_terms: D000438:Alcohols / Q000633:toxicity*; D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D004797:Enzyme-Linked Immunosorbent Assay; D000431:Ethanol / Q000633:toxicity*; D006801:Humans; D058847:Inflammasomes / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D000071199:NLR Family, Pyrin Domain-Containing 3 Protein / Q000187:drug effects* / Q000378:metabolism; D017027:Protein Tyrosine Phosphatases / Q000187:drug effects* / Q000378:metabolism
chemical_list: D000438:Alcohols; D058847:Inflammasomes; D000071199:NLR Family, Pyrin Domain-Containing 3 Protein; D000431:Ethanol; D017027:Protein Tyrosine Phosphatases