Discovery of potent and selective BRD4 inhibitors capable of blocking TLR3-induced acute airway inflammation

Eur J Med Chem. 2018 May 10:151:450-461. doi: 10.1016/j.ejmech.2018.04.006. Epub 2018 Apr 3.

Abstract

A series of diverse small molecules have been designed and synthesized through structure-based drug design by taking advantage of fragment merging and elaboration approaches. Compounds ZL0420 (28) and ZL0454 (35) were identified as potent and selective BRD4 inhibitors with nanomolar binding affinities to bromodomains (BDs) of BRD4. Both of them can be well docked into the acetyl-lysine (KAc) binding pocket of BRD4, forming key interactions including the critical hydrogen bonds with Asn140 directly and Tyr97 indirectly via a H2O molecule. Both compounds 28 and 35 exhibited submicromolar potency of inhibiting the TLR3-dependent innate immune gene program, including ISG54, ISG56, IL-8, and Groβ genes in cultured human small airway epithelial cells (hSAECs). More importantly, they also demonstrated potent efficacy reducing airway inflammation in a mouse model with low toxicity, indicating a proof of concept that BRD4 inhibitors may offer the therapeutic potential to block the viral-induced airway inflammation.

Keywords: Airway inflammation; Bromodomain-containing protein 4 (BRD4); Bromodomains; Immune response genes; Structure-based drug design.

MeSH terms

  • Animals
  • Anti-Inflammatory Agents / chemistry*
  • Anti-Inflammatory Agents / pharmacology*
  • Cell Cycle Proteins
  • Cell Line
  • Drug Design*
  • Humans
  • Immunity, Innate
  • Inflammation / drug therapy*
  • Inflammation / immunology
  • Male
  • Mice, Inbred C57BL
  • Molecular Docking Simulation
  • Nuclear Proteins / antagonists & inhibitors*
  • Nuclear Proteins / immunology
  • Respiratory Mucosa / drug effects*
  • Respiratory Mucosa / immunology
  • Structure-Activity Relationship
  • Toll-Like Receptor 3 / antagonists & inhibitors*
  • Toll-Like Receptor 3 / immunology
  • Transcription Factors / antagonists & inhibitors*
  • Transcription Factors / immunology

Substances

  • Anti-Inflammatory Agents
  • BRD4 protein, human
  • Cell Cycle Proteins
  • Nuclear Proteins
  • TLR3 protein, human
  • Toll-Like Receptor 3
  • Transcription Factors