Figure 1.

Human blood outgrowth endothelial cells adopt distinct cell states during sprouting angiogenesis. (a) Blood outgrowth endothelial cells (BOECs) derived from wet AMD and normal subjects were induced to sprout from cell-coated microcarrier beads in a fibrin gel sprouting angiogenesis assay, dissociated into single cell suspensions and subjected to single-cell RNA sequencing for downstream analysis. Images show confocal micrographs of representative normal and AMD BOECs at 24 h of the sprouting assay (red: f-actin; cyan: nuclei). Scale bar, 100 µm. (b) UMAP of integrated dataset showing derived endothelial clusters (left) and clustering tree depicting the relationships between clusters as resolution increases from 0.04 to 0.1 (right). Size of nodes (size) represents number of cells per cluster and color of nodes (Resolution) the resolution used to generate clusters. Numbers in each node represent cluster names in their corresponding resolutions. Edges are colored according to the number of cells from the incoming node (count). (c–f) Enrichment analysis of the top 100 cluster markers sorted by log2 fold change based on the Gene Ontology Biological Processes knowledgebase. Only top 10 enriched processes based on adjusted p values (p.adjust) are shown. Count indicates the number of genes within each term. (g) A heatmap of top 10 marker genes for each cluster and their corresponding expressions per cell.