Fig. 4

Overexpression of lipoprotein receptors in RPE cells allows for selective labeling of mature RPE cells by Dil-AcLDL uptake. a RT-qPCR analysis of gene expression in stem cells (day 0), retinal progenitors (day 7), low pigmentation RPE cells (~ day 45), and high pigmentation RPE cells (~ day 70). Gene expression results are represented as fold change relative to the geometric mean of three housekeeping genes: GAPDH, GPI, HMBS (n = 3). All pooled data represented as mean ± SEM; *p < 0.05, **p < 0.01, ***p < 0.001 [Student t test]. b Dil-AcLDL uptake assay. Fluorescence microscopy images of low-quality RPE monolayers challenged with Dil-AcLDL (red) for 2, 4, 6, and 12 h. c Colocalization of signals from Dil-AcLDL (red) uptake assay (overnight incubation) and FITC-POS (green) phagocytosis assay (6-h incubation). Black arrow: pigmented RPE cells. White arrow: non-RPE cells