Publication Date:
2012-06-15
Description:
Objective— Inflammatory leukocyte accumulation drives atherosclerosis. Although monocytes/macrophages and polymorphonuclear neutrophilic leukocytes (PMN) contribute to lesion formation, sequelae of myeloproliferative disease remain to be elucidated. Methods and Results— We used mice deficient in interferon regulatory factor 8 (IRF8 –/– ) in hematopoietic cells that develop a chronic myelogenous leukemia-like phenotype. Apolipoprotein E-deficient mice reconstituted with IRF8 –/– or IRF8 –/– apolipoprotein E-deficient bone marrow displayed an exacerbated atherosclerotic lesion formation compared with controls. The chronic myelogenous leukemia-like phenotype in mice with IRF8 –/– bone marrow, reflected by an expansion of PMN in the circulation, was associated with an increased lesional accumulation and apoptosis of PMN, and enlarged necrotic cores. IRF8 –/– compared with IRF8 +/+ PMN displayed unaffected reactive oxygen species formation and discharge of PMN granule components. In contrast, accumulating in equal numbers at sites of inflammation, IRF8 –/– macrophages were defective in efferocytosis, lipid uptake, and interleukin-10 cytokine production. Importantly, depletion of PMN in low-density lipoprotein receptor or apolipoprotein E-deficient mice with IRF8 –/– or IRF8 –/– apolipoprotein E-deficient bone marrow abrogated increased lesion formation. Conclusion— These findings indicate that a chronic myelogenous leukemia-like phenotype contributes to accelerated atherosclerosis in mice. Among proatherosclerotic effects of other cell types, this, in part, is linked to an expansion of functionally intact PMN.
Keywords:
Pathophysiology, Genetically altered mice, Other Vascular biology
Print ISSN:
1079-5642
Electronic ISSN:
1524-4636
Topics:
Medicine
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