Discovery of Potent, Specific, and Orally Available NLRP3 Inflammasome Inhibitors Based on Pyridazine Scaffolds for the Treatment of Septic Shock and Peritonitis

J Med Chem. 2024 Sep 12;67(17):15711-15737. doi: 10.1021/acs.jmedchem.4c01341. Epub 2024 Aug 21.

Abstract

The NLRP3 inflammasome is a multiprotein complex that is a component of the innate immune system, involved in the production of pro-inflammatory cytokines. Its abnormal activation is associated with many inflammatory diseases. In this study, we designed and synthesized a series of NLRP3 inflammasome inhibitors based on pyridazine scaffolds. Among them, P33 exhibited significant inhibitory effects against nigericin-induced IL-1β release in THP-1 cells, BMDMs, and PBMCs, with IC50 values of 2.7, 15.3, and 2.9 nM, respectively. Mechanism studies indicated that P33 directly binds to NLRP3 protein (KD = 17.5 nM), inhibiting NLRP3 inflammasome activation and pyroptosis by suppressing ASC oligomerization during NLRP3 assembly. Additionally, P33 displayed excellent pharmacokinetic properties, with an oral bioavailability of 62%. In vivo efficacy studies revealed that P33 significantly ameliorated LPS-induced septic shock and MSU crystal-induced peritonitis in mice. These results indicate that P33 has great potential for further development as a candidate for treating NLRP3 inflammasome-mediated diseases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Animals
  • Drug Discovery
  • Humans
  • Inflammasomes* / antagonists & inhibitors
  • Inflammasomes* / metabolism
  • Interleukin-1beta / antagonists & inhibitors
  • Interleukin-1beta / metabolism
  • Lipopolysaccharides / pharmacology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • NLR Family, Pyrin Domain-Containing 3 Protein* / antagonists & inhibitors
  • NLR Family, Pyrin Domain-Containing 3 Protein* / metabolism
  • Peritonitis* / drug therapy
  • Pyridazines* / chemical synthesis
  • Pyridazines* / chemistry
  • Pyridazines* / pharmacokinetics
  • Pyridazines* / pharmacology
  • Pyridazines* / therapeutic use
  • Shock, Septic* / drug therapy
  • Structure-Activity Relationship
  • THP-1 Cells

Substances

  • NLR Family, Pyrin Domain-Containing 3 Protein
  • Inflammasomes
  • Pyridazines
  • Interleukin-1beta
  • Lipopolysaccharides