Transdifferentiation of chick embryonic retinal pigment epithelial cells to lentoid structure in suspension culture.

To test transdifferentiation of retinal pigment epithelial (RPE) cells in suspension culture, chick embryonic RPE sheets and dissociated RPE cells were cultured for two months in a non-adherent dish for suspension culture. RPE cells, isolated as a sheet, aggregated immediately and remained the same size with their differentiated characteristics for two months. The presence of basic fibroblast growth factor (bFGF) at concentrations of 10 ng/ml or higher induced the formation of a spherical lentoid structure which was positive for crystallin and bFGF receptor. In contrast, dissociated RPE cells did reaggregate but did not develop the lentoid structure even in the presence of bFGF. The transdifferentiation of RPE cells to the lentoid structure in this study was in contrast to their transdifferentiation to the retina, as reported in a previous study.