CD163+ macrophages promote angiogenesis and vascular permeability accompanied by inflammation in atherosclerosis
Liang Guo, … , Renu Virmani, Aloke V. Finn
Liang Guo, … , Renu Virmani, Aloke V. Finn
Published February 19, 2018
Citation Information: J Clin Invest. 2018;128(3):1106-1124. https://doi.org/10.1172/JCI93025.
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Research Article Angiogenesis Vascular biology

CD163+ macrophages promote angiogenesis and vascular permeability accompanied by inflammation in atherosclerosis

Abstract

Intake of hemoglobin by the hemoglobin-haptoglobin receptor CD163 leads to a distinct alternative non–foam cell antiinflammatory macrophage phenotype that was previously considered atheroprotective. Here, we reveal an unexpected but important pathogenic role for these macrophages in atherosclerosis. Using human atherosclerotic samples, cultured cells, and a mouse model of advanced atherosclerosis, we investigated the role of intraplaque hemorrhage on macrophage function with respect to angiogenesis, vascular permeability, inflammation, and plaque progression. In human atherosclerotic lesions, CD163+ macrophages were associated with plaque progression, microvascularity, and a high level of HIF1α and VEGF-A expression. We observed irregular vascular endothelial cadherin in intraplaque microvessels surrounded by CD163+ macrophages. Within these cells, activation of HIF1α via inhibition of prolyl hydroxylases promoted VEGF-mediated increases in intraplaque angiogenesis, vascular permeability, and inflammatory cell recruitment. CD163+ macrophages increased intraplaque endothelial VCAM expression and plaque inflammation. Subjects with homozygous minor alleles of the SNP rs7136716 had elevated microvessel density, increased expression of CD163 in ruptured coronary plaques, and a higher risk of myocardial infarction and coronary heart disease in population cohorts. Thus, our findings highlight a nonlipid-driven mechanism by which alternative macrophages promote plaque angiogenesis, leakiness, inflammation, and progression via the CD163/HIF1α/VEGF-A pathway.

Authors

Liang Guo, Hirokuni Akahori, Emanuel Harari, Samantha L. Smith, Rohini Polavarapu, Vinit Karmali, Fumiyuki Otsuka, Rachel L. Gannon, Ryan E. Braumann, Megan H. Dickinson, Anuj Gupta, Audrey L. Jenkins, Michael J. Lipinski, Johoon Kim, Peter Chhour, Paul S. de Vries, Hiroyuki Jinnouchi, Robert Kutys, Hiroyoshi Mori, Matthew D. Kutyna, Sho Torii, Atsushi Sakamoto, Cheol Ung Choi, Qi Cheng, Megan L. Grove, Mariem A. Sawan, Yin Zhang, Yihai Cao, Frank D. Kolodgie, David P. Cormode, Dan E. Arking, Eric Boerwinkle, Alanna C. Morrison, Jeanette Erdmann, Nona Sotoodehnia, Renu Virmani, Aloke V. Finn

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Figure 4

M(Hb) macrophages promote vascular permeability via VEGF-A/VEGFR2 signaling.

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M(Hb) macrophages promote vascular permeability via VEGF-A/VEGFR2 signal...
(A) TEER measurements after treatment of scramble siRNA– (Scr) or VEGFR2 siRNA–transfected HAECs with supernatant from control macrophages [M(con)] or HH-differentiated [M(Hb)] macrophages. The relative TEER compared with control is shown (n = 4 per group). (B) FITC-dextran permeability in scramble siRNA– or VEGFR2 siRNA–transfected HAECs treated with control or HH-differentiated macrophage supernatants. Percentage change of FITC-dextran compared with control (n = 4 per group). (C) Immunofluorescence imaging of scramble siRNA– or VEGFR2 siRNA–transfected HAECs treated with control or HH-differentiated macrophage supernatants for VE-cadherin (green) and DAPI (blue) (original magnification, ×60). Scale bar: 50 μm. Note the loss of plasma membrane VE-cadherin in endothelial cells treated with M(Hb) supernatants versus M(con) supernatants and the restoration of membrane VE-cadherin in endothelial cells transfected with VEGFR2 siRNA and treated with M(Hb) supernatants. (D) Quantitation of plasma membrane VE-cadherin in the experiment shown in C (n = 10 per group). (E) Immunoblot of the membrane fraction from scramble siRNA– or VEGFR2 siRNA–transfected HAECs treated with control or HH-differentiated macrophage supernatants, with quantitation of densitometry for VE-cadherin (n = 4 per group). (F) Quantitation of plasma membrane VE-cadherin in the experiment shown in E. All error bars indicate the mean ± SEM. *P < 0.05 versus other groups. For multiple group comparisons, a 1-way ANOVA was applied. If the variance ratio test (F test) was significant, a more detailed post-hoc analysis of differences between groups was done using a Tukey-Kramer honest significant difference test.