Gene Expression Profiles and Retinal Potential of Stem/Progenitor Cells Derived from Human Iris and Ciliary Pigment Epithelium

The aim of our study was to isolate and characterize the properties of neurospheres and differentiated cellular progeny derived from iris and ciliary pigment epithelial (IPE and CPE) cells of human cadaveric eyes. In this study we investigated the gene expression profiles of the stem/progenitor cells and the differentiated progeny derived from IPE and CPE cells, as the changes underlying differentiation of the stem/progenitor derived from the IPE and CPE cells from human cadaveric eye are essentially unknown. The IPE and CPE cells from human cadaver eyes were cultured in the presence of mitogens to generate neurospheres (NS) and the growth characteristics were evaluated. The Neurospheres (NS) were plated under conditions inducing differentiation and their potential was analyzed by RT-PCR, immunocytochemistry, calcium imaging studies and microarray studies to measure the changes involved in the process of differentiation. The IPE and CPE cells can generate NS containing progenitor cells in the presence of mitogens and were capable of producing different retinal cell types as demonstrated by RT-PCR and immunocytochemistry. The cluster analyses of the differentially expressed genes show the dynamic changes that occur during the course of IPE and CPE neurospheres differentiating into retinal progeny. The study gives clues towards the changes that occur during differentiation from NS into retinal progeny. In the present study we have demonstrated the expansion and maintenance of SCs from IPE and CPE of cadaveric eyes. These cells maintain their self-renewal properties and the ability to differentiate along retinal cell lineages and hence could be a practical source of donor cells for ex-vivo stem cell therapy during retinal degeneration.