1. Academic Validation
  2. Saturated fatty acids induce NLRP3 activation in human macrophages through K+ efflux resulting from phospholipid saturation and Na, K-ATPase disruption

Saturated fatty acids induce NLRP3 activation in human macrophages through K+ efflux resulting from phospholipid saturation and Na, K-ATPase disruption

  • Biochim Biophys Acta Mol Cell Biol Lipids. 2019 Jul;1864(7):1017-1030. doi: 10.1016/j.bbalip.2019.04.001.
Marco A Gianfrancesco 1 Jonas Dehairs 2 Laurent L'homme 3 Gaëtan Herinckx 4 Nathalie Esser 1 Olivia Jansen 5 Yvette Habraken 6 Cédric Lassence 6 Johan V Swinnen 2 Mark H Rider 4 Jacques Piette 6 Nicolas Paquot 1 Sylvie Legrand-Poels 7
Affiliations

Affiliations

  • 1 Laboratory of Immunometabolism and Nutrition, GIGA-Inflammation, Infection & Immunity, University of Liège, Liège, Belgium; Division of Diabetes, Nutrition and Metabolic Disorders, Department of Medicine, University Hospital of Liège, Liège, Belgium.
  • 2 Laboratory of Lipid Metabolism and Cancer, Department of Oncology, KU Leuven, Leuven, Belgium.
  • 3 University of Lille, Inserm, University Hospital of Lille, Pasteur Institute of Lille, U1011 - EGID, F-59000 Lille, France.
  • 4 de Duve Institute, Catholic University of Louvain, 1200 Brussels, Belgium.
  • 5 Laboratory of Pharmacognosy, CIRM, University of Liège, Liège, Belgium.
  • 6 Laboratory of Virology and Immunology, GIGA-Molecular Biology of Diseases, University of Liège, Liège, Belgium.
  • 7 Laboratory of Immunometabolism and Nutrition, GIGA-Inflammation, Infection & Immunity, University of Liège, Liège, Belgium. Electronic address: s.legrand@uliege.be.
Abstract

NLRP3 inflammasome plays a key role in Western diet-induced systemic inflammation and was recently shown to mediate long-lasting trained immunity in myeloid cells. Saturated fatty acids (SFAs) are sterile triggers able to induce the assembly of the NLRP3 inflammasome in macrophages, leading to IL-1β secretion while unsaturated ones (UFAs) prevent SFAs-mediated NLRP3 activation. Unlike previous studies using LPS-primed bone marrow derived macrophages, we do not see any ROS or IRE-1α involvement in SFAs-mediated NLRP3 activation in human monocytes-derived macrophages. Rather we show that SFAs need to enter the cells and to be activated into acyl-CoA to lead to NLRP3 activation in human macrophages. However, their β-oxidation is dispensable. Instead, they are channeled towards Phospholipids but redirected towards lipid droplets containing triacylglycerol in the presence of UFAs. Lipidomic analyses and Laurdan fluorescence experiments demonstrate that SFAs induce a dramatic saturation of phosphatidylcholine (PC) correlated with a loss of membrane fluidity, both events inhibited by UFAs. The silencing of CCTα, the key Enzyme in PC synthesis, prevents SFA-mediated NLRP3 activation, demonstrating the essential role of the de novo PC synthesis. This SFA-induced membrane remodeling promotes a disruption of the plasma membrane Na, K-ATPase, instigating a K+ efflux essential and sufficient for NLRP3 activation. This work opens novel therapeutic avenues to interfere with Western diet-associated diseases such as those targeting the glycerolipid pathway.

Keywords

Free fatty acids; K(+) efflux; K-ATPase; NLRP3 inflammasome; Na; Obesity; Phospholipid.

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Products
  • Cat. No.
    Product Name
    Description
    Target
    Research Area
  • HY-15845
    ≥98.0%, IRE1 Inhibitor