Authors: Wu Wei, Qu Ya, Wang Lei, Zeng Yuxiao, Xu Haiwei, Yin Zhengqin
Normal ultrastructure is the anatomical basis of retinal pigment epithelial(RPE)cells to perform normal physiological function.At present the precipitation method is often used to detect the ultrastructure of RPE cells with transmission electron microscopy(TEM).
The aim of this study was to explore a simple and feasible approach to examine the ultrastructure of human embryonic stem cell-derived retinal pigment epithelial (hESC-RPE) cells.
hESCs were induced and differentiated into RPE cells by the spontaneous differentiation method, and the expressions of microphthalmia associated transcription factor MITF and paired-box gene 6 (PAX6), specific protein of RPE cells, in the cells were detected by immunofluorescence assay.hESC-RPE cells were inoculated into Transwell filter, and the ultrastructure of the cell sheet was examined under the TEM.Then the ultrastructure of the cell sheet specimens was compared with those of hESC-RPE cells from cell precipitation and RPE cell specimens of 90-day-old Long Evans rats.
MITF and PAX6 were positively expressed in hESC-RPE cells.The normal ultrastructure were visible in the RPE cells of rats under the TEM, including apical microvilli, polarized melanin granules, cellular nucleus, basement membrane and intercellular junctions, and the ultrastructure of hESC-RPE cell sheet on Transwell was similar to the RPE cells in rats.However, only scatter melanin granules, nonpolar nucleus and scanty microvilli were observed under the TEM in the hESC-RPE cells by cell precipitation method.
Without digestion process, hESC-RPE cell sheet on Transwell can retain the normal ultrastructure of hESC-RPE cells under the TEM, with a more simple and reliable advantage.