Reversal of vascular macrophage accumulation and hypertension by a CCR2 antagonist in deoxycorticosterone/salt-treated mice

Hypertension. 2012 Nov;60(5):1207-12. doi: 10.1161/HYPERTENSIONAHA.112.201251. Epub 2012 Oct 1.

Abstract

Infiltration of macrophages into the artery wall plays detrimental roles during hypertension by promoting vascular inflammation and endothelial dysfunction, and it occurs via a chemo-attractant action of chemokines on macrophage cytokine receptors. We sought to identify the key chemokine receptors associated with macrophage infiltration into the vascular wall during deoxycorticosterone acetate (DOCA)/salt-induced hypertension in mice and to evaluate the impact of pharmacological inhibition of these receptors on blood pressure and leukocyte accumulation. Mice treated with DOCA/salt for 21 days displayed markedly elevated systolic blood pressure (158 ± 2 versus 114 ± 5 mm Hg in sham group; P<0.0001). Polymerase chain reaction screening via a gene array of 20 chemokine receptors indicated an increased expression of CCR2 in aortas of DOCA/salt-treated mice. Real-time polymerase chain reaction confirmed mRNA upregulation of CCR2 in aortas from DOCA/salt-treated animals and of the CCR2 ligands CCL2, CCL7, CCL8, and CCL12 (all >2-fold versus sham; P<0.05). Flow cytometry revealed 2.9-fold higher macrophage numbers (ie, CD45(+) CD11b(+) F4/80(+) cells) in the aortic wall of DOCA/salt versus sham-treated mice. Intervention with a CCR2 antagonist, INCB3344 (30 mg/kg per day, IP), 10 days after the induction of hypertension with DOCA/salt treatment, reduced the aortic expression of CCR2 mRNA and completely reversed the DOCA/salt-induced influx of macrophages. Importantly, INCB3344 substantially reduced the elevated blood pressure in DOCA/salt-treated mice. Hence, our findings highlight CCR2 as a promising therapeutic target to reduce both macrophage accumulation in the vascular wall and blood pressure in hypertension.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Aorta / drug effects
  • Aorta / metabolism
  • Aorta / pathology
  • Blood Pressure / drug effects*
  • Blood Pressure / genetics
  • Chemokine CCL2 / genetics
  • Chemokine CCL7 / genetics
  • Chemokine CCL8 / genetics
  • Desoxycorticosterone
  • Flow Cytometry
  • Gene Expression / drug effects
  • Gene Expression Profiling
  • Hypertension / chemically induced
  • Hypertension / genetics
  • Hypertension / prevention & control*
  • Macrophages / drug effects*
  • Macrophages / metabolism
  • Macrophages / pathology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Monocyte Chemoattractant Proteins / genetics
  • Pyrrolidines / pharmacology*
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Receptors, CCR2 / antagonists & inhibitors*
  • Receptors, CCR2 / genetics
  • Reverse Transcriptase Polymerase Chain Reaction
  • Sodium Chloride
  • Up-Regulation / drug effects

Substances

  • Ccl12 protein, mouse
  • Ccl2 protein, mouse
  • Ccl7 protein, mouse
  • Ccl8 protein, mouse
  • Ccr2 protein, mouse
  • Chemokine CCL2
  • Chemokine CCL7
  • Chemokine CCL8
  • INCB3344
  • Monocyte Chemoattractant Proteins
  • Pyrrolidines
  • RNA, Messenger
  • Receptors, CCR2
  • Desoxycorticosterone
  • Sodium Chloride