Spatial transcriptomic profiling of coronary endothelial cells in SARS-CoV-2 myocarditis

Figure 1. Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infects the myocardium and promotes differential expression patterns in patients with severe COVID-19. Histological analysis of the myocardium stained by H&E (A) or by immunofluorescence for SARS-CoV-2 nucleocapsid and CD31 expression (B). Circles highlight representative ROIs. Heterogeneous expression of SARS-CoV-2 was noted among COVID-19 samples. Initially, global transcriptional changes (independent of ROIs) were examined in myocardial tissue by combining all myocardial ROI results based upon COVID-19 status. 1,454 Genes were above the limit of quantification. Compared to controls, PCA of unsupervised data revealed pattern clustering and differential expression within COVID-19 patients (C), data presented per ROI. Gene-expression analysis (D), observed 25 differentially expressed genes from myocardial tissues (differential expression was defined as p = 0.02 and log2 fold change of 0.4). A gene heatmap (E), illustrates the greatest differentially expressed genes. Following global analysis, marker-defined ROIs were segmented by SARS-CoV-2 nucleocapsid expression for gene-expression analysis (F), representative image…

Figure 2. Severe COVID-19 is not associated with differential programming of the coronary arterial or venous endothelium. Coronary vascular endothelial cells were identified by immunofluorescence and selectively sampled for spatial transcriptomics (A), white custom tracings illustrate representative replicate ROIs. In addition to control samples, COVID-19 patient samples were stained for SARS-CoV-2 nucleocapsid and stratified into quartiles based upon relative MFI with the bottom quartile defined as SARS-CoV-2 “Low” and the top quartile defined as SARS-CoV-2 “high.” 1,302 genes were above the limit of quantification. Despite marked heterogeneity in SARS-CoV-2 expression, principal component analysis failed to show pattern clustering (B). Similarly, minimal differences in transcriptional programming were observed as only nine genes were observed to be differentially expressed between control and COVID-19 coronary endothelium (C), data include ROIs from SARS-CoV-2 low and high samples. Differential gene expression was defined as p = 0.02 and log2 fold change of 0.4. COVID-19 (n = 8 patients, 30 ROIs) and Control (n = 4 patients, 15 ROIs). Scale bars are 250 μm for each image.