N-3 vs. n-6 fatty acids differentially influence calcium signalling and adhesion of inflammatory activated monocytes: impact of lipid rafts

Inflamm Res. 2016 Nov;65(11):881-894. doi: 10.1007/s00011-016-0971-9. Epub 2016 Jul 6.


Background: Anti-inflammatory n-3 fatty acids (FA) like docosahexaenoic acid (DHA) opposed to the pro-inflammatory n-6 FA arachidonic acid (AA) might modulate lipid rafts within the cell membrane by differential incorporation. In inflammation, monocyte adhesion to endothelial cells is a crucial step mediated by intracellular calcium changes. We investigated whether lipid rafts mediate FA-induced modulation of adhesion and intracellular calcium.

Methods: In isolated human monocytes and monocytic U937 cells we measured adhesion to human umbilical vein endothelial cells (HUVEC) using a parallel flow chamber and a static assay, adhesion molecules by FACScan, and intracellular calcium by fluorescence. Monocyte lipid rafts were isolated by ultracentrifugation and submitted to gas chromatography for FA analysis.

Results: Pre-incubation with AA or DHA resulted in a predominant incorporation of the respective FA into raft compared to non-raft fraction. DHA as compared to AA significantly reduced monocyte adhesion and calcium release after stimulation with TNF-α while expression of adhesion molecules remained unchanged. Pre-treatment with a calcium chelator abolished the effect of FA on calcium and adhesion. Disruption of lipid rafts prevented FA-induced modulations.

Conclusion: Incorporation of FA into lipid rafts seem to be crucial for modulation of adhesion under inflammatory conditions.

Keywords: Adhesion; Calcium; Fatty acids; Inflammation; Lipid rafts.

MeSH terms

  • Antigens, CD / metabolism
  • Arachidonic Acid / pharmacology*
  • Calcium Signaling / drug effects
  • Cell Adhesion / drug effects
  • Cells, Cultured
  • Docosahexaenoic Acids / pharmacology*
  • Human Umbilical Vein Endothelial Cells / drug effects
  • Human Umbilical Vein Endothelial Cells / metabolism
  • Human Umbilical Vein Endothelial Cells / physiology
  • Humans
  • Membrane Microdomains / drug effects*
  • Membrane Microdomains / metabolism
  • Monocytes / drug effects*
  • Monocytes / metabolism
  • Monocytes / physiology
  • Tumor Necrosis Factor-alpha / pharmacology
  • U937 Cells


  • Antigens, CD
  • Tumor Necrosis Factor-alpha
  • Docosahexaenoic Acids
  • Arachidonic Acid