Differential changes in GPR55 during microglial cell activation

FEBS Lett. 2009 Jun 18;583(12):2071-6. doi: 10.1016/j.febslet.2009.05.028. Epub 2009 May 22.


We examined how lipopolysaccharide (LPS) and interferon gamma (IFN-gamma), known to differentially activate microglia, affect the expression of G protein-coupled receptor 55 (GPR55), a novel cannabinoid receptor. We found that GPR55 mRNA is significantly expressed in both primary mouse microglia and the BV-2 mouse microglial cell line, and that LPS down-regulates this message. Conversely, IFN-gamma slightly decreases GPR55 mRNA in primary microglia, while it upregulates this message in BV-2 cells. Moreover, the GPR55 agonist, lysophosphatidylinositol, increases ERK phosphorylation in BV-2 stimulated with IFN-gamma, in correlation with the increased amount of GPR55 mRNA. Remarkably, these stimuli-induced changes in GPR55 expression are similar to those observed with CB(2)-R, suggesting that both receptors might be involved in neuroinflammation and that their expression is concomitantly controlled by the state of microglial activation.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Cannabinoid Receptor Agonists
  • Cell Line
  • Cells, Cultured
  • DNA Primers / genetics
  • Gene Expression / drug effects
  • Interferon-gamma / pharmacology
  • Lipopolysaccharides / pharmacology
  • Lysophospholipids / pharmacology
  • Mice
  • Microglia / drug effects
  • Microglia / metabolism*
  • Mitogen-Activated Protein Kinase 1 / metabolism
  • Mitogen-Activated Protein Kinase 3 / metabolism
  • Phosphorylation
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Receptors, Cannabinoid / genetics*
  • Receptors, Cannabinoid / metabolism*
  • Recombinant Proteins


  • Cannabinoid Receptor Agonists
  • DNA Primers
  • GPR55 protein, mouse
  • Lipopolysaccharides
  • Lysophospholipids
  • RNA, Messenger
  • Receptors, Cannabinoid
  • Recombinant Proteins
  • lysophosphatidylinositol
  • Interferon-gamma
  • Mitogen-Activated Protein Kinase 1
  • Mitogen-Activated Protein Kinase 3