Coronary artery disease (CAD), the direct result of atherosclerosis, is the most common cause of death in the USA and other western countries. Decreasing CAD risk by current therapies confers incomplete protection from myocardial infarctions. Since coronary plaques begin their progression in childhood, new directions are needed to reverse them. Our understanding of atherosclerosis regression, however, lags far behind what is known about plaque progression. This proposal represents the combined efforts of 3 laboratories with complementary expertise to expand conceptually and technically the efforts to address this imbalance that the previous funding cycles have supported. There is increasing recognition that plaque progression represents a failure to resolve inflammation. The central inflammatory cell in the plaque is the macrophage. Macrophages can differentiate from infiltrating monocytes of hematopoietic origin during inflammatory responses or are derived from resident progenitors that are already seeded in the tissues during embryonic development. Type 1 cytokines (e.g., IFNg) and TLR agonists classically activate macrophages (referred to as M1 macrophages), whereas the Type 2 cytokines IL- 4 and IL-13 will alternatively activate macrophages (referred to as M2 macrophages). While the majority of macrophages in mouse and human plaques have the M1 phenotype, we have found that plaque regression in a variety of mouse models we have introduced is characterized by the enrichment of macrophages that are in the alternatively activated M2 state. Furthermore, exciting preliminary data strongly suggest that this enrichment is required for regression and that IL-4 is the key cytokine regulating this enrichment. The major objective, then, of this proposal is to more deeply understand the source, regulation, and function of M2 macrophages in plaque regression. We propose to:
Aim 1 : Test the hypothesis that M2 macrophages in regressing plaques are derived from newly recruited infiltrating Ly6C high monocytes.
Aim 2 : Determine the cellular source of IL-4 responsible for polarizing M2 macrophages in regressing plaques.
Aim 3 : Test the hypothesis that M2 macrophages in regressing plaques are regulating inflammatory responses by promoting the differentiation of Foxp3+ regulatory T cells, which are known to be anti- inflammatory and atheroprotective in progressing plaques.

Public Health Relevance

Current treatments of coronary artery disease, the direct result of atherosclerosis, still leave many patients at significant risk of heart attacks and stroks. Using novel mouse models, we have shown that the high inflammatory state of disease-causing cells in atherosclerosis, macrophages, is not permanent as previously thought, and our major goal is to learn the mechanisms by which these cells can be made to be anti- inflammatory and regress the plaques. The results should point to key pathways and targets to augment current therapeutic approaches.

National Institute of Health (NIH)
National Heart, Lung, and Blood Institute (NHLBI)
Research Project (R01)
Project #
Application #
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Liu, Lijuan
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
New York University
Internal Medicine/Medicine
Schools of Medicine
New York
United States
Zip Code
Loke, P'ng; Niewold, Timothy B (2017) By CyTOF: Heterogeneity of Human Monocytes. Arterioscler Thromb Vasc Biol 37:1423-1424
Yu, Mikyung; Amengual, Jaume; Menon, Arjun et al. (2017) Targeted Nanotherapeutics Encapsulating Liver X Receptor Agonist GW3965 Enhance Antiatherogenic Effects without Adverse Effects on Hepatic Lipid Metabolism in Ldlr-/- Mice. Adv Healthc Mater 6:
Arlauckas, Sean P; Garris, Christopher S; Kohler, Rainer H et al. (2017) In vivo imaging reveals a tumor-associated macrophage-mediated resistance pathway in anti-PD-1 therapy. Sci Transl Med 9:
Ruparelia, Neil; Chai, Joshua T; Fisher, Edward A et al. (2017) Inflammatory processes in cardiovascular disease: a route to targeted therapies. Nat Rev Cardiol 14:133-144
Barrett, Tessa J; Murphy, Andrew J; Goldberg, Ira J et al. (2017) Diabetes-mediated myelopoiesis and the relationship to cardiovascular risk. Ann N Y Acad Sci 1402:31-42
Rahman, Karishma; Vengrenyuk, Yuliya; Ramsey, Stephen A et al. (2017) Inflammatory Ly6Chi monocytes and their conversion to M2 macrophages drive atherosclerosis regression. J Clin Invest 127:2904-2915
Fisher, Edward A (2016) Regression of Atherosclerosis: The Journey From the Liver to the Plaque and Back. Arterioscler Thromb Vasc Biol 36:226-35
Iqbal, Asif J; Fisher, Edward A; Greaves, David R (2016) Inflammation-a Critical Appreciation of the Role of Myeloid Cells. Microbiol Spectr 4:
Miller, Miles A; Gadde, Suresh; Pfirschke, Christina et al. (2015) Predicting therapeutic nanomedicine efficacy using a companion magnetic resonance imaging nanoparticle. Sci Transl Med 7:314ra183
Zhang, Xue-Qing; Even-Or, Orli; Xu, Xiaoyang et al. (2015) Nanoparticles containing a liver X receptor agonist inhibit inflammation and atherosclerosis. Adv Healthc Mater 4:228-36

Showing the most recent 10 out of 71 publications