Spontaneous generation of a novel foetal human retinal pigment epithelium (RPE) cell line available for investigation on phagocytosis and morphogenesis.

Objectives: Primary retinal pigment epithelium (RPE) cells have a limited capacity to re-establish epithelial morphology and to maintain native RPE function in vitro, and all commercially available RPE cell lines have drawbacks of morphology or function; therefore, the establishment of new RPE cell lines with typical characteristics of RPE would be helpful in further understanding of their physiological and pathological mechanisms. Here, we firstly report a new spontaneously generated RPE line, fhRPE-13A, from a 13-week aborted foetus. We aimed to investigate its availability as a RPE model. Materials and methods: RNA-seq data were mapped to the human genome assembly hg19. Global transcriptional data were analysed by Weighted Gene Co-expression Network Analysis (WGCNA) and differentially expressed genes (DEGs). The morphology and molecular characteristics were examined by immunofluorescence, transmission electron micrographs, PCR and western blot. Photoreceptor outer segments (POS) phagocytosis assay and transepithelial resistance measurement (TER) were performed to assess phagocytic activity and barrier function, respectively. Results: The fhRPE-13A cells showed typical polygonal morphology and normal biological processes of RPE. Meanwhile they were capable of POS phagocytosis in vitro, and the expression level of TYR and TYRP1 were significantly higher than that in ARPE-19 cells. Conclusions: The foetal human RPE line fhRPE-13A is a valuable system for researching phagocytosis and morphogenesis of RPE in vitro.