Fig. 4

iPSC-derived choroidal endothelial cells express CD31, CA4, and RGCC. Representative immunocytochemical staining of endothelial cell-specific markers CD31 (a, e red), CA4 (c, g red), and RGCC (d, h red) in differentiated cells post-endothelial cell enrichment via CD31-positive MACS sorting (a–d) or CDH5 lentiviral zeocin selection (e–h). Positivity was determined via comparison to secondary antibody-only controls (b, f and inserts in top right corner). Cells were co-stained for actin (green), and nuclei were counterstained with DAPI. Scale bars = 50 μM. (i) CA4 and RGCC expression are enriched in primary human choriocapillaris endothelial cells (CC) opposed to primary human arterial (Artery) and venous (Vein) choroidal endothelial cells [26]. To calculate the relative expression of each gene compared to the choriocapillaris cluster (x-axis), the average expression of CA4 and RGCC were calculated for each cell type and divided by the mean expression in the choriocapillaris cluster. Alexa Fluro 488-labeled acetylated LDL uptake in iPSC-derived choroidal endothelial cells post-CD31 MACS sort (j, k) and zeocin selection (l, m)