Hematopoietic G-protein-coupled receptor kinase 2 deficiency decreases atherosclerotic lesion formation in LDL receptor-knockout mice

FASEB J. 2013 Jan;27(1):265-76. doi: 10.1096/fj.12-205351. Epub 2012 Oct 9.

Abstract

Leukocyte chemotaxis is deemed instrumental in initiation and progression of atherosclerosis. It is mediated by G-protein-coupled receptors (e.g., CCR2 and CCR5), the activity of which is controlled by G-protein-coupled receptor kinases (GRKs). In this study, we analyzed the effect of hematopoietic deficiency of a potent regulator kinase of chemotaxis (GRK2) on atherogenesis. LDL receptor-deficient (LDLr(-/-)) mice with heterozygous hematopoietic GRK2 deficiency, generated by bone marrow transplantation (n=15), displayed a dramatic attenuation of plaque development, with 79% reduction in necrotic core and increased macrophage content. Circulating monocytes decreased and granulocytes increased in GRK2(+/-) chimeras, which could be attributed to diminished granulocyte colony-forming units in bone marrow. Collectively, these data pointed to myeloid cells as major mediators of the impaired atherogenic response in GRK2(+/-) chimeras. LDLr(-/-) mice with macrophage/granulocyte-specific GRK2 deficiency (LysM-Cre GRK2(flox/flox); n=8) failed to mimic the aforementioned phenotype, acquitting these cells as major responsible subsets for GRK2 deficiency-associated atheroprotection. To conclude, even partial hematopoietic GRK2 deficiency prevents atherosclerotic lesion progression beyond the fatty streak stage, identifying hematopoietic GRK2 as a potential target for intervention in atherosclerosis.

Publication types

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

MeSH terms

  • Animals
  • Apoptosis
  • Atherosclerosis / genetics
  • Atherosclerosis / pathology*
  • Female
  • Flow Cytometry
  • G-Protein-Coupled Receptor Kinase 2 / genetics*
  • Mice
  • Mice, Knockout
  • Phagocytosis
  • Receptors, LDL / genetics*

Substances

  • Receptors, LDL
  • GRK2 protein, mouse
  • G-Protein-Coupled Receptor Kinase 2