Single-cell transcriptional profiling reveals subpopulational expression of vascular endothelial CCRL2 by proatherosclerosis stimulation. (A) Uniform Manifold Approximation and Projection (UMAP) plot illustrating cell clusters identified in the full single-cell dataset from the left carotid artery of wild-type mice 1 or 2 days after partial carotid ligation (PCL) surgery or without PCL (non-PCL). (B) Violin plots of CCRL2 expression in five EC clusters. (C) UMAP projection of all endothelial cells identified in the full single-cell dataset from the aortic root of ApoE^−/− mice fed a high fat diet (HFD) for 0 or 16 weeks. (D) Violin plots of CCRL2 expression in three EC clusters. (E) Male ApoE^−/− mice were fed HFD for 0, 4, 8, or 12 weeks. Aortic CCRL2 mRNA expression was determined by real-time quantitative PCR (RT–qPCR), normalized to GAPDH and displayed as fold-change induction relative to baseline (HFD for 0 week) (n = 5 mice per group). **P < 0.01, ****P < 0.0001 by one-way ANOVA with Dunnett’s test for multiple comparisons. (F) Aortic CCRL2 protein expression detected by Western blotting was normalized to β-actin and displayed as fold-changes relative to baseline (n = 3 mice per group). Full blots can be found in the Supplementary material online, Figure S8A. **P < 0.01, ***P < 0.001 by one-way ANOVA with Dunnett’s test for multiple comparisons. (G) Aortic sections from ApoE^−/− mice fed HFD for 4 weeks were stained for CCRL2 and CD31. Bar = 20 μm.