Angiotensin II up-regulates CX3CR1 expression in THP-1 monocytes: impact on vascular inflammation and atherogenesis

J Thromb Thrombolysis. 2010 May;29(4):443-8. doi: 10.1007/s11239-009-0424-1.

Abstract

The potential regulatory effect of angiotensins on circulating mononuclear cell activation and migration has not yet been thoroughly evaluated. Using flow cytometry we assessed the possible effect of angiotensin I and II on the expression of CX3CR1 and a single representative of each major chemokine family (CCR5 and CXCR4) in THP-1 monocytes, Jurcat T lymphocytes and primary monocytes-isolated from healthy donors. Fluorescence intensity and the rate of chemokine-positive cells was measured in naïve cells and cells treated with angiotensin I and II. Neither angiotensin I nor angiotensin II exhibited any effect on fluorescence intensity and the rate of CX3CR1-, CCR5- and CXCR4-positive cells in primary peripheral blood mononuclear cells and Jurkat T cells. However, angiotensin II significantly increased the rate of CX3CR1-positive THP-1 cells. This effect was not attenuated by the pre-incubation of THP-1 cells with the AT-1 receptor blocker losartan, suggesting that this was not an AT-1-mediated effect. Angiotensin I and II had no effect on fluorescence intensity and the rate of CCR5- and CXCR4-positive THP-1 cells. In conclusion, angiotensin II increases the rate of CX3CR1-positive THP-1 cells. By extrapolating this in vitro observation to disease mechanisms, we speculate that angiotensin II induces up-regulation of CX3CR1 and promotes firm adhesion of circulation CX3CR1-positive monocytes on CX3CL1 expressing endothelial cells inducing vascular inflammation and atherogenesis.

MeSH terms

  • Angiotensin I / metabolism
  • Angiotensin I / pharmacology
  • Angiotensin II / metabolism
  • Angiotensin II / pharmacology*
  • Angiotensin II Type 1 Receptor Blockers
  • Atherosclerosis / metabolism*
  • CX3C Chemokine Receptor 1
  • Cell Adhesion / drug effects
  • Cell Movement / drug effects
  • Chemokine CX3CL1 / biosynthesis
  • Endothelial Cells / metabolism
  • Gene Expression Regulation / drug effects*
  • Humans
  • Inflammation / metabolism
  • Jurkat Cells
  • Losartan / pharmacology
  • Monocytes / metabolism*
  • Receptors, CCR5 / biosynthesis
  • Receptors, CXCR4 / biosynthesis
  • Receptors, Chemokine / biosynthesis*
  • Vasculitis / metabolism*
  • Vasoconstrictor Agents / metabolism
  • Vasoconstrictor Agents / pharmacology*

Substances

  • Angiotensin II Type 1 Receptor Blockers
  • CX3C Chemokine Receptor 1
  • CX3CL1 protein, human
  • CX3CR1 protein, human
  • CXCR4 protein, human
  • Chemokine CX3CL1
  • Receptors, CCR5
  • Receptors, CXCR4
  • Receptors, Chemokine
  • Vasoconstrictor Agents
  • Angiotensin II
  • Angiotensin I
  • Losartan