Macrophage transcriptomic profiling shows enhanced macrophage scavenging activity in the liver of S/S mice. (A) Five macrophage subsets identified by MERFISH of liver tissues from 1.5-month-old A/A and S/S mice at baseline, visualized in UMAP (white-line boxed inset) and liver tissues in situ. Each color represents 1 macrophage subtype. Each dot represents 1 cell. These images show significantly increased monocytes or macrophages in the liver of S/S mouse, with remarkable accumulation around the vessels. (B) Comparisons of hepatic spatial transcriptomic profiles between 1.5-month-old A/A and S/S mice using the 300-general inflammation and thrombosis MERFISH gene panel. Each color and its corresponding RNA species are shown in the gene color key box on the right. Each dot represents 1 RNA molecule. (C) Comparisons of hepatic macrophage transcriptomic profiles between 4 groups of mice, 2-month-old A/A and S/S mice at baseline and 2-month-old A/A and S/S mice after TNF challenge using the 140-monocyte or macrophage MERFISH gene panel. Each color and its corresponding RNA species are shown on the right in the gene color key box. Each dot represents 1 RNA molecule. (D) Quantifications of transcript numbers per cell for Csf1, Marco, Mrc1, and Hmox1 genes between the livers of A/A and S/S mice in (C). Welch 2-sample t test. (E) Three-dimensional (3D) rendering of confocal images showing the clearance of VWF and erythrocytes by macrophages in the liver of A/A and S/S mice. Side views are shown on the right and bottom. DAPI cell nuclear staining (n = 3 mice per group). (F) Quantification of the colocalization of F4/80⁺ macrophages with VWF (bottom) and erythrocytes (top). These images demonstrate the increased clearance of VWF and erythrocytes by macrophages in the liver of S/S mice. Data represent mean ± standard deviation. ∗∗P < .01; ∗∗∗∗P < .0001, 2-tailed, unpaired Student t test. F4/80, macrophage marker; RBC, red blood cell; Ter119, erythrocyte marker.