Abstract
Purpose: :
Cell transplantation as a therapy for degenerative ocular diseases such as age related macular degeneration (AMD) has received significant attention. The retinal pigment epithelium would be the primary target for cellular replacement in AMD. Transplantation with a patients own cells would avoid rejection however it is impractical to obtain autologous RPE. Thus other cell types within the eye are being considered. In particular the iris pigment epithelium has been investigated. The IPE and RPE share common developmental origins and in vitro IPE cells can acquire a number of important RPE specific phenotypic and functional characteristics. Thus we aimed to isolate and culture human IPE cells derived from trabeculectomy surgery.
Methods: :
Using a method adapted from MacNeil et al. 2007. Briefly IPE cells were isolated from the trabecular meshwork by enzymatic digestion. Dissociated cells were cultured in suspension for one week, followed by a further week as adherent cultures. Phenotype, viability and differentiation potential were then assessed by immunocytochemistry.
Results: :
Isolated IPE cells readily formed neurospheres with well defined hypopigmented outer margins in the presence of basic fibroblast growth factor and epidermal growth factor. Following monolayer culture cells expressed markers characteristic of neural stem/progenitor cells (Pax6). Viability as determined by cleaved caspase-3 immunoreactivity was approximately 90%. Cultured IPE cells were also positive for mature retinal specific markers including recoverin.
Conclusions: :
These preliminary findings are indicative of a niche of cells within the human adult IPE which have a multipotent capacity for differentiation.Funding: Gift of Sight and ForesightRef: MacNeil A, Pearson RA, MacLaren RE et al (2007). Comparative Analysis of Progenitor Cells Isolated From the Iris, Pars Plana and Ciliary Body of the Adult Porcine Eye. Stem Cells.
Keywords: iris • microscopy: light/fluorescence/immunohistochemistry • plasticity