Abstract
Purpose: :
Within the adult human post mortem retina our work has identified a population of cells expressing the stem cell marker CD133. Our present aim has been to phenotype purified CD133+ cells from post-mortem retina and investigate their functional ability (neurosphere generation) when exposed to Leukaemia Inhibitory Factor (LIF) or IL-6, with a wider aim to analyse gene expression following exposure to these cytokines.
Methods: :
Retinal cell suspensions were derived from adult human post-mortem tissue with ethical approval and CD133+ cells were isolated using Automated Magnetic Cell Sorting (MACS®). Purified CD133+ retinal cells were fully analysed for cell phenotype using FACS, observed for neurosphere generation and RNA was extracted for gene analysis.
Results: :
CD133+ retinal cells dipslayed phenotype of Nestinhi, CD135hi, CD90hi, CD271hi, NCAMhi, Pax-6hi, DBXlo, RHODlo, GFAPlo, LIFRlo, Notch-1lo, RECOVERINlo and CD31-, CD45-, ABCG2-, CRALBP-, VIMENTIN-, CD34-, CD117-, NANOG- by FACS. LIF supplementation increased extent of expression of Ki67 and Cyclin D, CD135, Notch and BrdU incorporation. Culture overnight with FGF/N2 further increased Nestin, DBX and Pax-6, expression which influenced the expression of transcription factors governing generation of post-mitotic retinal cells.
Conclusions: :
Populations of CD133+ retinal cells are pre-mitotic and express Ki67, BrdU and Cyclin D as well as progenitor cell markers (Nestin, CD135, PAX6, notch). These cells have limited proliferative capacity but increased by LIF inferring a low frequency of cell renewal in vivo. Affymetrix indentified candidate genes associated with cell turnover and retinal cell development .
Keywords: regeneration • retina • retinal culture