Non-selective cation channel activity is required for lysophosphatidylcholine-induced monocyte migration

J Cell Physiol. 2009 Nov;221(2):325-34. doi: 10.1002/jcp.21857.

Abstract

Lysophosphatidylcholine (LPC) is a major atherogenic lipid which stimulates the recruitment of monocytes to atherosclerotic lesions. The physiological mechanisms underlying LPC-induced monocyte migration are poorly understood. Here we demonstrate that LPC activates non-selective cation channels, which are significantly involved in LPC-induced chemotaxis of monocytes. External LPC elicited the activation of non-selective cation currents in THP-1 monocytes, which occurred in a G protein and phospholipase C-independent manner. LPC-activated currents were almost completely inhibited by Gd(3+), La(3+), and TRAM-34. Furthermore, currents were partially reduced by either 2-aminoethoxydiphenyl borate (2-APB) or ruthenium red, while combined application of 2-APB and ruthenium red abolished LPC-activated currents. The 2-APB-sensitive current component was potentiated by flufenamic acid and Ca(2+)-free extracellular solution, while the ruthenium red-sensitive current component was abolished by capsazepine. This pharmacological profile suggests that LPC simultaneously activates TRPC6 and TRPV1 channels in monocytes. Furthermore, in the presence of Gd(3+), La(3+), TRAM-34, 2-APB, ruthenium red or capsazepine, LPC-induced chemotaxis of monocytes was substantially inhibited, indicating that activation of both channel types is required for optimal migration of LPC-stimulated monocytes. Thus, ion channel inhibition may represent a powerful strategy to attenuate the progression of atherosclerosis by reducing monocyte infiltration.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Boron Compounds / pharmacology
  • Cations / metabolism
  • Cell Line
  • Cell Movement / drug effects*
  • Estrenes / pharmacology
  • GTP-Binding Proteins / metabolism
  • Gadolinium / pharmacology
  • Humans
  • Ion Channel Gating / drug effects*
  • Ion Channels / metabolism*
  • Lanthanum / pharmacology
  • Lysophosphatidylcholines / pharmacology*
  • Monocytes / cytology*
  • Monocytes / drug effects*
  • Monocytes / metabolism
  • Pyrazoles / pharmacology
  • Pyrrolidinones / pharmacology
  • Ruthenium Red / pharmacology
  • Type C Phospholipases / metabolism

Substances

  • Boron Compounds
  • Cations
  • Estrenes
  • Ion Channels
  • Lysophosphatidylcholines
  • Pyrazoles
  • Pyrrolidinones
  • TRAM 34
  • Ruthenium Red
  • 1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione
  • Lanthanum
  • Gadolinium
  • 2-aminoethoxydiphenyl borate
  • Type C Phospholipases
  • GTP-Binding Proteins