• Home
  • Search Results
  • Surfactant inhibits ATP-induced release of interleukin-1β via nicotinic acetylcholine receptors.

Surfactant inhibits ATP-induced release of interleukin-1β via nicotinic acetylcholine receptors.

Journal of lipid research (2017-04-14)
Sören Backhaus, Anna Zakrzewicz, Katrin Richter, Jelena Damm, Sigrid Wilker, Gabriele Fuchs-Moll, Mira Küllmar, Andreas Hecker, Ivan Manzini, Clemens Ruppert, J Michael McIntosh, Winfried Padberg, Veronika Grau
ABSTRACT

Interleukin (IL)-1β is a potent pro-inflammatory cytokine of innate immunity involved in host defense. High systemic IL-1β levels, however, cause life-threatening inflammatory diseases, including systemic inflammatory response syndrome. In response to various danger signals, the pro-form of IL-1β is synthesized and stays in the cytoplasm unless a second signal, such as extracellular ATP, activates the inflammasome, which enables processing and release of mature IL-1β. As pulmonary surfactant is known for its anti-inflammatory properties, we hypothesize that surfactant inhibits ATP-induced release of IL-1β. Lipopolysaccharide-primed monocytic U937 cells were stimulated with an ATP analog in the presence of natural or synthetic surfactant composed of recombinant surfactant protein (rSP)-C, palmitoylphosphatidylglycerol, and dipalmitoylphosphatidylcholine (DPPC). Both surfactant preparations dose-dependently inhibited IL-1β release from U937 cells. DPPC was the active constituent of surfactant, whereas rSP-C and palmitoylphosphatidylglycerol were inactive. DPPC was also effective in primary mononuclear leukocytes isolated from human blood. Experiments with nicotinic antagonists, siRNA technology, and patch-clamp experiments suggested that stimulation of nicotinic acetylcholine receptors (nAChRs) containing subunit α9 results in a complete inhibition of the ion channel function of ATP receptor, P2X7. In conclusion, the surfactant constituent, DPPC, efficiently inhibits ATP-induced inflammasome activation and maturation of IL-1β in human monocytes by a mechanism involving nAChRs.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Monoclonal Anti-β-Actin antibody produced in mouse, clone AC-74, purified immunoglobulin, buffered aqueous solution
Sigma-Aldrich
Lipopolysaccharides from Escherichia coli O26:B6, γ-irradiated, BioXtra, suitable for cell culture
Sigma-Aldrich
2′(3′)-O-(4-Benzoylbenzoyl)adenosine 5′-triphosphate triethylammonium salt, ≥93%
Sigma-Aldrich
Leu-Leu methyl ester hydrobromide, ≥97% (TLC)
Sigma-Aldrich
Apyrase from potatoes, ATPase ≥200 units/mg protein, lyophilized powder
Sigma-Aldrich
Strychnine hydrochloride
Sigma-Aldrich
1,2-Dipalmitoyl-sn-glycero-3-phosphoethanolamine, ≥97%
Sigma-Aldrich
2-Oleoyl-1-palmitoyl-sn-glycero-3-phospho-rac-(1-glycerol) sodium salt, ≥98.0% (TLC)
Sigma-Aldrich
1,2-Dipalmitoyl-sn-glycerol, ≥99%