title: Discovery and validation of a new class of small molecule Toll-like receptor 4 (TLR4) inhibitors.
abstract: Many inflammatory diseases may be linked to pathologically elevated signaling via the receptor for lipopolysaccharide (LPS), toll-like receptor 4 (TLR4). There has thus been great interest in the discovery of TLR4 inhibitors as potential anti-inflammatory agents. Recently, the structure of TLR4 bound to the inhibitor E5564 was solved, raising the possibility that novel TLR4 inhibitors that target the E5564-binding domain could be designed. We utilized a similarity search algorithm in conjunction with a limited screening approach of small molecule libraries to identify compounds that bind to the E5564 site and inhibit TLR4. Our lead compound, C34, is a 2-acetamidopyranoside (MW 389) with the formula C17H27NO9, which inhibited TLR4 in enterocytes and macrophages in vitro, and reduced systemic inflammation in mouse models of endotoxemia and necrotizing enterocolitis. Molecular docking of C34 to the hydrophobic internal pocket of the TLR4 co-receptor MD-2 demonstrated a tight fit, embedding the pyran ring deep inside the pocket. Strikingly, C34 inhibited LPS signaling ex-vivo in human ileum that was resected from infants with necrotizing enterocolitis. These findings identify C34 and the β-anomeric cyclohexyl analog C35 as novel leads for small molecule TLR4 inhibitors that have potential therapeutic benefit for TLR4-mediated inflammatory diseases.
authors.affiliation: Division of Pediatric Surgery Children's Hospital of Pittsburgh and Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Neal
authors.forename: Hongpeng
authors.initials: H
authors.lastname: Jia
authors.forename: Benjamin
authors.initials: B
authors.lastname: Eyer
authors.forename: Misty
authors.initials: M
authors.lastname: Good
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Guerriero
authors.forename: Chhinder P
authors.initials: CP
authors.lastname: Sodhi
authors.forename: Amin
authors.initials: A
authors.lastname: Afrazi
authors.forename: Thomas
authors.initials: T
authors.lastname: Prindle
authors.forename: Congrong
authors.initials: C
authors.lastname: Ma
authors.forename: Maria
authors.initials: M
authors.lastname: Branca
authors.forename: John
authors.initials: J
authors.lastname: Ozolek
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Brodsky
authors.forename: Peter
authors.initials: P
authors.lastname: Wipf
authors.forename: David J
authors.initials: DJ
authors.lastname: Hackam
mesh_terms: D000117:Acetylglucosamine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D000704:Analysis of Variance; D000818:Animals; D001665:Binding Sites / Q000235:genetics; D017931:DNA Primers / Q000235:genetics; D055808:Drug Discovery / Q000379:methods*; D020345:Enterocolitis, Necrotizing / Q000188:drug therapy; D020895:Enterocytes / Q000378:metabolism; D006801:Humans; D007249:Inflammation / Q000188:drug therapy*; D008050:Lipid A / Q000031:analogs & derivatives / Q000378:metabolism; D008264:Macrophages / Q000378:metabolism; D051379:Mice; D011485:Protein Binding; D060888:Real-Time Polymerase Chain Reaction; D054852:Small Molecule Libraries; D051197:Toll-Like Receptor 4 / Q000037:antagonists & inhibitors*; D014316:Tritium
chemical_list: D017931:DNA Primers; C404742:E5564; D008050:Lipid A; D054852:Small Molecule Libraries; D051197:Toll-Like Receptor 4; D014316:Tritium; D000117:Acetylglucosamine