Fig. 1: Ferroptosis is elevated in post-mortem COVID-19 lungs.

a Representative images of H&E-stained COVID-19 lung autopsies with ALI and non-ALI pathology and non-infected control lungs. ALI case shows characteristic hyaline membranes lining the alveolar walls (asterisks). Non-ALI case shows congestion and hemangiomatosis-like changes in the alveolar wall (arrows). Scale bar = 100 μm. b Representative images of immunofluorescence (IF) staining using anti-TfR1 antibody (clone 3F3-FMA) and anti-MDA antibody (clone 1F83). Nuclei are shown in blue, and antibodies are shown in red. Scale bar = 20 μm. c The mean intensity of TfR1 signal of each case is normalized to the mean of non-infected control group. Data shown as mean ± SEM, n = 9 (control), n = 11 (ALI), n = 10 (non-ALI), one-way ANOVA (p value indicated). d Non-COVID-19 ALI cases were immunohistochemistry (IHC) stained with anti-TfR1 antibody (clone H68.4). Positive stain area is normalized to control group. Data shown as mean ± SEM, n = 6 (control), n = 13 (non-COVID), unpaired two-sided t test. e The mean intensity of MDA signal is normalized to the non-infected control group. Data shown as mean ± SEM, n = 9 (control), n = 11 (ALI), n = 10 (non-ALI), one-way ANOVA (p value indicated). f COVID-19 and control cases were stained with anti-phospho-MLKL, anti-cleaved Caspase 3, and anti-cleaved Gasdermin D antibodies. The mean intensity of each antibody is normalized to the control group. Data shown as mean ± SEM, n = 9 (control), n = 11 (ALI), n = 10 (non-ALI) (left and middle panel), one-way ANOVA. n = 5 (control), n = 10 (non-ALI) (right panel), unpaired two-sided t test.