Imeglimin attenuates NLRP3 inflammasome activation by restoring mitochondrial functions in macrophages

J Pharmacol Sci. 2024 Jun;155(2):35-43. doi: 10.1016/j.jphs.2024.03.004. Epub 2024 Mar 27.

Abstract

Imeglimin is a novel oral antidiabetic drug for treating type 2 diabetes. However, the effect of imeglimin on NLRP3 inflammasome activation has not been investigated yet. Here, we aimed to investigate whether imeglimin reduces LPS-induced NLRP3 inflammasome activation in THP-1 macrophages and examine the associated underlying mechanisms. We analyzed the mRNA and protein expression levels of NLRP3 inflammasome components and IL-1β secretion. Additionally, reactive oxygen species (ROS) generation, mitochondrial membrane potential, and mitochondrial permeability transition pore (mPTP) opening were measured by flow cytometry. Imeglimin inhibited NLRP3 inflammasome-mediated IL-1β production in LPS-stimulated THP-1-derived macrophages. In addition, imeglimin reduced LPS-induced mitochondrial ROS production and mitogen-activated protein kinase phosphorylation. Furthermore, imeglimin restored the mitochondrial function by modulating mitochondrial membrane depolarization and mPTP opening. We demonstrated for the first time that imeglimin reduces LPS-induced NLRP3 inflammasome activation by inhibiting mPTP opening in THP-1 macrophages. These results suggest that imeglimin could be a promising new anti-inflammatory agent for treating diabetic complications.

Keywords: Imeglimin; Inflammasome; Mitochondrial permeability transition pore (mPTP); Reactive oxygen species (ROS); THP-1 cells.

MeSH terms

  • Anti-Inflammatory Agents / pharmacology
  • Humans
  • Hypoglycemic Agents / pharmacology
  • Inflammasomes* / drug effects
  • Inflammasomes* / metabolism
  • Interleukin-1beta* / metabolism
  • Lipopolysaccharides*
  • Macrophages* / drug effects
  • Macrophages* / metabolism
  • Membrane Potential, Mitochondrial* / drug effects
  • Mitochondria* / drug effects
  • Mitochondria* / metabolism
  • Mitochondrial Membrane Transport Proteins / metabolism
  • Mitochondrial Permeability Transition Pore / metabolism
  • Mitogen-Activated Protein Kinases / metabolism
  • NLR Family, Pyrin Domain-Containing 3 Protein* / metabolism
  • Phosphorylation / drug effects
  • Reactive Oxygen Species* / metabolism
  • THP-1 Cells

Substances

  • NLR Family, Pyrin Domain-Containing 3 Protein
  • Inflammasomes
  • Reactive Oxygen Species
  • Interleukin-1beta
  • NLRP3 protein, human
  • Lipopolysaccharides
  • Anti-Inflammatory Agents
  • Mitochondrial Permeability Transition Pore
  • Mitochondrial Membrane Transport Proteins
  • Hypoglycemic Agents
  • Mitogen-Activated Protein Kinases