title: 3,4-methylenedioxy-β-nitrostyrene inhibits NLRP3 inflammasome activation by blocking assembly of the inflammasome.
abstract: The NLRP3 inflammasome is a critical component of the innate immune system. NLRP3 activation is induced by diverse stimuli associated with bacterial infection or tissue damage, but its inappropriate activation is involved in the pathogenesis of inherited and acquired inflammatory diseases. However, the mechanism by which NLRP3 is activated remains poorly understood. In this study, we explored the role of kinases in NLRP3 inflammasome activation by screening a kinase inhibitor library and identified 3,4-methylenedioxy-β-nitrostyrene (MNS) as an inhibitor for NLRP3 inflammasome activation. Notably, MNS did not affect the activation of the NLRC4 or AIM2 (absent in melanoma 2) inflammasome. Mechanistically, MNS specifically prevented NLRP3-mediated ASC speck formation and oligomerization without blocking potassium efflux induced by NLRP3 agonists. Surprisingly, Syk kinase, the reported target of MNS, did not mediate the inhibitory activity of MNS on NLRP3 inflammasome activation. We also found that the nitrovinyl group of MNS is essential for the inhibitory activity of MNS. Immunoprecipitation, mass spectrometry, and mutation studies suggest that both the nucleotide binding oligomerization domain and the leucine-rich repeat domain of NLRP3 were the intracellular targets of MNS. Administration of MNS also inhibited NLRP3 ATPase activity in vitro, suggesting that MNS blocks the NLRP3 inflammasome by directly targeting NLRP3 or NLRP3-associated complexes. These studies identified a novel chemical probe for studying the molecular mechanism of NLRP3 inflammasome activation which may advance the development of novel strategies to treat diseases associated with abnormal activation of NLRP3 inflammasome.
authors.affiliation: From the Department of Pathology and Comprehensive Cancer Center, University of Michigan Medical School, Ann Arbor, Michigan 48109.
authors.forename: Yuan
authors.initials: Y
authors.lastname: He
authors.forename: Saranyaraajan
authors.initials: S
authors.lastname: Varadarajan
authors.forename: Raúl
authors.initials: R
authors.lastname: Muñoz-Planillo
authors.forename: Aaron
authors.initials: A
authors.lastname: Burberry
authors.forename: Yuumi
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Gabriel
authors.initials: G
authors.lastname: Núñez
mesh_terms: D000251:Adenosine Triphosphatases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D015153:Blotting, Western; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D004148:Dioxolanes / Q000737:chemistry / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D057809:HEK293 Cells; D006801:Humans; D058847:Inflammasomes / Q000235:genetics / Q000378:metabolism*; D053583:Interleukin-1beta / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D008856:Microscopy, Fluorescence; D015394:Molecular Structure; D000071199:NLR Family, Pyrin Domain-Containing 3 Protein; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D000072377:Syk Kinase; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: C514815:3,4-methylenedioxy-beta-nitrostyrene; D002352:Carrier Proteins; D004148:Dioxolanes; D004791:Enzyme Inhibitors; D058847:Inflammasomes; D053583:Interleukin-1beta; D047908:Intracellular Signaling Peptides and Proteins; D008070:Lipopolysaccharides; D000071199:NLR Family, Pyrin Domain-Containing 3 Protein; C492716:Nlrp3 protein, mouse; D014409:Tumor Necrosis Factor-alpha; D000255:Adenosine Triphosphate; D011505:Protein-Tyrosine Kinases; C000606896:SYK protein, human; D000072377:Syk Kinase; C000606897:Syk protein, mouse; D000251:Adenosine Triphosphatases
keywords: Caspase; Inflammation; Innate Immunity; Macrophages; NOD-like Receptor (NLR)