Extended Data Fig. 5: RBC haemolysis in models of SARS-CoV-2 infection, cardiac LAD ligation and heart transplant.
From: Ischaemic endothelial necroptosis induces haemolysis and COVID-19 angiopathy
a-c, SARS-CoV-2 model. Illustrations of a transverse view of heart, with regions containing RBC haemolysis shaded in pink (a). Representative H&E and confocal images of the same cardiac vessel (white boxes) showing haemolysed RBCs (TER-119+H, arrows) co-localized with necrotic ECs (Nuclei: pale diffused cyan, H&E inset yellow box: pale blue); Scale bar, 20 µm (a), and quantification of haemolysed RBC aggregates in SARS-CoV-2 and control (mock) organs (n = 3 mice/group) (b). H&E and confocal fluorescence images of adjacent tissue sections showing little or no RBC haemolysis in the lungs (left, fluorescence) and brain (right, fluorescence) microvasculature of SARS-CoV-2 mice, despite the tissue injury marked by leukocyte infiltration (left, H&E: lungs) or neuronal injury (right, brain: H&E), relative to mock controls. Scale bars, 100 µm and 20 µm (n = 3 mice/organ)(c). d, LAD model. Illustrations depict a cross-sectional view of heart with tissue damage (purple shade) and intravascular RBC haemolysis (pink shade). Representative H&E and confocal images showing the same vessel (white boxes) with haemolysed RBCs (TER-119+H, arrows) co-localized with necrotic ECs (Nuclei: pale diffused cyan; H&E inset yellow box: pale blue) (Sham: n = 6, LAD-IR: n = 7). Scale bars, 20 µm. e, Heart transplant model. Representative H&E and fluorescent (IF) images of two adjacent tissue sections showing a lack of intravascular RBC haemolysis, despite the intensive inflammatory responses (H&E); graphs quantify the number of haemolysed RBC aggregates (left) and EC death (right) in mice at day 1, 5 and 7 post-transplant (n = 6); Scale bars, 200 and 100 µm.
