CD36-dependent 7-ketocholesterol accumulation in macrophages mediates progression of atherosclerosis in response to chronic air pollution exposure

Xiaoquan Rao, Jixin Zhong, Andrei Maiseyeu, Bhavani Gopalakrishnan, Frederick A. Villamena, Lung Chi Chen, Jack R. Harkema, Qinghua Sun, Sanjay Rajagopalan

Research output: Contribution to journalArticle

73 Scopus citations

Abstract

Rationale: Air pollution exposure has been shown to potentiate plaque progression in humans and animals. Our previous studies have suggested a role for oxidized lipids in mediating adverse vascular effect of air pollution. However, the types of oxidized lipids formed in response to air pollutants and how this occurs and their relevance to atherosclerosis are not fully understood. Objective: To investigate the mechanisms by which particulate matter <2.5 μm (PM2.5) induces progression of atherosclerosis. Methods and Results: Atherosclerosis-prone ApoE-/- or LDLR-/- mice were exposed to filtered air or concentrated ambient PM2.5 using a versatile aerosol concentrator enrichment system for 6 months. PM2.5 increased 7-ketocholesterol (7-KCh), an oxidatively modified form of cholesterol, in plasma intermediate density lipoprotein/low-density lipoprotein fraction and in aortic plaque concomitant with progression of atherosclerosis and increased CD36 expression in plaque macrophages from PM2.5-exposed mice. Macrophages isolated from PM2.5-exposed mice displayed increased uptake of oxidized lipids without alterations in their efflux capacity. Consistent with these finding, CD36-positive macrophages displayed a heightened capacity for oxidized lipid uptake. Deficiency of CD36 on hematopoietic cells diminished the effect of air pollution on 7-KCh accumulation, foam cell formation, and atherosclerosis. Conclusions: Our results suggest a potential role for CD36-mediated abnormal accumulations of oxidized lipids, such as 7-KCh , in air pollution-induced atherosclerosis progression. (Circ Res. 2014;115:770-780.)

Original languageEnglish (US)
Pages (from-to)770-780
Number of pages11
JournalCirculation research
Volume115
Issue number9
DOIs
StatePublished - Jan 1 2014

Keywords

  • 7-ketocholesterol
  • Air pollution
  • Atherosclerosis
  • Foam cells
  • Macrophages
  • Particulate matter

ASJC Scopus subject areas

  • Physiology
  • Cardiology and Cardiovascular Medicine

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    Rao, X., Zhong, J., Maiseyeu, A., Gopalakrishnan, B., Villamena, F. A., Chen, L. C., Harkema, J. R., Sun, Q., & Rajagopalan, S. (2014). CD36-dependent 7-ketocholesterol accumulation in macrophages mediates progression of atherosclerosis in response to chronic air pollution exposure. Circulation research, 115(9), 770-780. https://doi.org/10.1161/CIRCRESAHA.115.304666