Caffeic Acid Cyclohexylamide Rescues Lethal Inflammation in Septic Mice through Inhibition of IκB Kinase in Innate Immune Process

Sci Rep. 2017 Feb 1:7:41180. doi: 10.1038/srep41180.

Abstract

Targeting myeloid differentiation protein 2 (MD-2) or Toll-like receptor 4 (TLR4) with small molecule inhibitor rescues the systemic inflammatory response syndrome (SIRS) in sepsis due to infection with Gram-negative bacteria but not other microbes. Herein, we provided IκB kinase β (IKKβ) in innate immune process as a molecular target of caffeic acid cyclohexylamide (CGA-JK3) in the treatment of polymicrobial TLR agonists-induced lethal inflammation. CGA-JK3 ameliorated E. coli lipopolysaccharide (LPS, MD-2/TLR4 agonist)-induced endotoxic shock, cecal ligation and puncture (CLP)-challenged septic shock or LPS plus D-galactosamine (GalN)-induced acute liver failure (ALF) in C57BL/6J mice. As a molecular basis, CGA-JK3 inhibited IKKβ-catalyzed kinase activity in a competitive mechanism with respect to ATP, displaced fluorescent ATP probe from the complex with IKKβ, and docked at the ATP-binding active site on the crystal structure of human IKKβ. Furthermore, CGA-JK3 inhibited IKKβ-catalyzed IκB phosphorylation, which is an axis leading to IκB degradation in the activating pathway of nuclear factor-κB (NF-κB), in macrophages stimulated with TLR (1/2, 2/6, 4, 5, 7, 9) agonists from Gram-positive/negative bacteria and viruses. CGA-JK3 consequently interrupted IKKβ-inducible NF-κB activation and NF-κB-regulated expression of TNF-α, IL-1α or HMGB-1 gene, thereby improving TLRs-associated redundant inflammatory responses in endotoxemia, polymicrobial sepsis and ALF.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Inflammatory Agents / administration & dosage*
  • Anti-Inflammatory Agents / chemistry
  • Anti-Inflammatory Agents / pharmacology
  • Binding Sites
  • Caffeic Acids / administration & dosage*
  • Caffeic Acids / chemistry
  • Caffeic Acids / pharmacology
  • Cyclohexylamines / administration & dosage*
  • Cyclohexylamines / chemistry
  • Cyclohexylamines / pharmacology
  • Disease Models, Animal
  • Galactosamine / adverse effects*
  • Gene Expression Regulation / drug effects
  • I-kappa B Kinase / chemistry
  • I-kappa B Kinase / metabolism*
  • Lipopolysaccharides / administration & dosage*
  • Liver Failure, Acute / chemically induced
  • Liver Failure, Acute / drug therapy*
  • Liver Failure, Acute / immunology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Models, Molecular
  • Molecular Docking Simulation
  • Phosphorylation / drug effects
  • RAW 264.7 Cells
  • Shock, Septic / chemically induced
  • Shock, Septic / drug therapy*
  • Shock, Septic / immunology

Substances

  • Anti-Inflammatory Agents
  • Caffeic Acids
  • Cyclohexylamines
  • Lipopolysaccharides
  • Galactosamine
  • I-kappa B Kinase
  • Ikbkb protein, mouse