Journal: Cardiovascular Research

Article Title: Single-cell to pre-clinical evaluation of Trem2 , Folr2 , and Slc7a7 as macrophage-associated biomarkers for atherosclerosis

doi: 10.1093/cvr/cvaf210

Figure Lengend Snippet: Comparative analysis of gene expression and sTREM2 levels in mouse and human samples. ( A ) Venn diagram illustrating the overlap of gene expression profiling results from mouse aorta samples analysed by TRAP-Seq and scRNA-Seq, and human coronary arteries analysed by scRNA-Seq, revealing a subset of genes enriched in macrophages. The analysis identifies 388 macrophage-enriched genes, of which 164 are membrane proteins, 33 are metabolic proteins, and 54 are receptor proteins. Sample sizes: TRAP-Seq n = 6 mice, mouse scRNA-Seq n = 3 mice, and human scRNA-Seq n = 4 patients. ( B ) Detailed lists of identified proteins categorized into metabolic proteins and receptor proteins from A . ( C ) Expression of Trem2 , Slc7a7 and Folr2 in TRAP-Seq and scRNA-Seq of mouse aorta. For TRAP-Seq, values represent the average transcripts per million across IP replicates, while for scRNA-Seq, they correspond to cluster pseudobulk counts per million. Gene expression for each method is scaled per gene from 0 to 1, with 1 representing the maximum observed expression. Sample sizes are as indicated in panel A . ( D ) Quantification of soluble (s)TREM2 in the plasma of mice carrying (+) or not carrying (−) the hypercholesterolemic LDLR −/− ApoB 100/100 mutations. The mice were subjected to either a regular diet (0) or a high-fat diet (HFD) for 1 or 3 months. Data are presented for both 12-month-old and 21-month-old mice, illustrating the impact of diet and age. The Wilcoxon rank sum test was used for comparing groups. Sample size (mice per group) at 12 months was 7 (−; HFD 0), 5 (+; HFD 0), 5 (+; HFD 1), 7 (−; HFD 3) and 4 (+; HFD 3), and at 21 months was 25 (−) and 30 (+). ( E , F ) Normalized protein expression (NPX levels of TREM2 in ( E ) human atherosclerotic tissue and ( F ) plasma from individuals of the BiKE cohort in individuals with asymptomatic (AS) and symptomatic (S) carotid stenosis. NPX was calculated as recommended by Olink and is on a log 2 scale in arbitrary units (one NPX difference corresponds to 2-fold in protein concentration). Each dot represents an individual patient's sTREM2 levels, with 50 patients in each group. Statistical significance was measured using a two-sided Student’s t -test with unequal variance. ( G ) Heatmap of Pearson correlation coefficients between plasma and tissue TREM2 levels (atherosclerotic aortic arterial wall = aorta, liver, and mammary artery = m.artery) in 165 coronary artery disease patients from the STARNET cohort. ( H ) Pearson correlation matrix showing relationships between plasma sTREM2, C-reactive protein, serum cholesterol, low-density lipoprotein cholesterol, and triglycerides in 20 individuals from the BiKE cohort. For both panels, the colour scale represents the Pearson correlation coefficient ( r ), ranging from −1 to +1. Asterisks denote statistical significance: * P < 0.05, ** P < 0.01, *** P < 0.001, **** P < 0.0001.

Article Snippet: The plates were washed five times with washing buffer, followed by a 1-h incubation at RT with a biotinylated mouse anti-TREM2 antibody (BAF1729, 1:3000, R&D Systems).

Techniques: Gene Expression, Membrane, Expressing, Clinical Proteomics, Protein Concentration