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.
View: Text | PDF
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

×

Figure 2

Alternative CD163+ macrophages are associated with intraplaque angiogenesis and vascular permeability and express HIF1α and VEGF-A.

Options: View larger image (or click on image) Download as PowerPoint
Alternative CD163+ macrophages are associated with intraplaque angiogene...
Human plaques from CEA specimens were analyzed by histology and immunofluorescence. Images were acquired by confocal microscopy using ×40 (A and E) or ×60 (C, RNAscope) objectives, with optical slicing in the z axis. (A) Representative microvessels (MV) from low and high CD163 areas (green) dual immunostained for HIF1α and VEGF-A (red channels). Scale bars: 20 μm. (B) immunoblotting for CD163, HIF1α, VEGF-A, and GAPDH of protein extracted from human atheroma expressing high or low levels of CD163 (n = 4 samples each). Bar graphs show quantitation of densitometry for the indicated proteins. (C) RNAscope ISH analysis using CD163 (red) and VEGF (green) probes on human carotid plaques. H&E and CD163 immunohistochemically stained images of human carotid plaques are shown on the left to indicate the areas (red boxes) of RNAscope ISH images of CD163 and VEGF, shown on the right. Scale bars: 1 mm (H&E- and immunostained images) and 2 μm (ISH). (D) Quantitative graph of VEGF RNA punctate counts in macrophages with low (<1–4 punctates) or high (≥5 punctates) CD163 expression (total of 3 plaques used for data collection, with 5 to 6 areas per plaque). (E) representative microvessels from low and high CD163 areas (green) dual immunostained for VE-cadherin and vWF (red channels). Note that VE-cadherin expression is located exclusively along the interendothelial contacts. The fluorescence signal for VE-cadherin appeared to be attenuated in a microvessel surrounded by CD163+ macrophages, with diffuse expression of vWF antigen, suggestive of leaky endothelial junctions. Scale bars: 20 μm. (F) Bar graphs show quantification of fluorescence signals for VE-cadherin and vWF in low and high CD163 areas (multiple areas from a total of 10 plaques per group were examined; see Methods). (G) Laser capture microdissection and qPCR analysis of FPN expression in low CD163+ and high CD163+ macrophage areas (n = 15 plaques sampled). Results are presented as the mean ± SEM (B and F) or the mean ± SD (D and G). (B and F) *P < 0.05, by 2-sided Student’s t test. (D and G) P < 0.01 and P < 0.05, by 2-sided Student’s t test.