Discovery of novel small molecule TLR4 inhibitors as potent anti-inflammatory agents

Eur J Med Chem. 2018 Jun 25:154:253-266. doi: 10.1016/j.ejmech.2018.05.033. Epub 2018 May 22.

Abstract

Toll-like receptor 4 (TLR4) initiates innate immune response to release inflammatory cytokines and has been pathologically linked to variety of inflammatory diseases. Recently, we found that Carvedilol, as the classic anti-heart failure and anti-inflammatory clinic drug, could inhibit the TLR4 signaling in the TLR4 overexpressed cells. Herein, we have designed and synthesized a small library of novel Carvedilol derivatives and investigated their potential inhibitory activity. The results indicate that the most potent compound 8a (SMU-XY3) could effectively inhibited TLR4 protein and the LPS triggered alkaline phosphatase signaling in HEK-Blue hTLR4 cells. It down regulated the nitric oxide (NO) in both RAW264.7 cells and BV-2 microglial cells, in addition to blocking the TNF-α signaling in ex-vivo human peripheral blood mononuclear cells (PBMC). More interestingly, 8a shows higher affinity to hyperpolarization-activated cyclic nucleotide-gated 4 (HCN4) over HCN2, which probably indicates the new application of TLR4 inhibitor 8a in heart failure, coronary heart disease, and other inflammatory diseases.

Keywords: Anti-Inflammatory; Carvedilol derivative; Small molecule antagonist; Toll-like receptor 4.

MeSH terms

  • Animals
  • Anti-Inflammatory Agents, Non-Steroidal / chemical synthesis
  • Anti-Inflammatory Agents, Non-Steroidal / chemistry
  • Anti-Inflammatory Agents, Non-Steroidal / pharmacology*
  • Carbazoles / chemical synthesis
  • Carbazoles / chemistry
  • Carbazoles / pharmacology*
  • Carvedilol
  • Cell Line
  • Dose-Response Relationship, Drug
  • Drug Discovery*
  • Humans
  • Leukocytes, Mononuclear / drug effects
  • Leukocytes, Mononuclear / metabolism
  • Mice
  • Molecular Structure
  • Nitric Oxide / antagonists & inhibitors
  • Nitric Oxide / biosynthesis
  • Propanolamines / chemical synthesis
  • Propanolamines / chemistry
  • Propanolamines / pharmacology*
  • RAW 264.7 Cells
  • Signal Transduction / drug effects
  • Small Molecule Libraries / chemical synthesis
  • Small Molecule Libraries / chemistry
  • Small Molecule Libraries / pharmacology*
  • Structure-Activity Relationship
  • Toll-Like Receptor 4 / antagonists & inhibitors*
  • Toll-Like Receptor 4 / metabolism
  • Tumor Necrosis Factor-alpha / antagonists & inhibitors
  • Tumor Necrosis Factor-alpha / metabolism

Substances

  • Anti-Inflammatory Agents, Non-Steroidal
  • Carbazoles
  • Propanolamines
  • Small Molecule Libraries
  • TLR4 protein, human
  • Toll-Like Receptor 4
  • Tumor Necrosis Factor-alpha
  • Carvedilol
  • Nitric Oxide