American researchers have reported the discovery of a way to isolate retinal pigmented epithelial (RPE) cells as early as 14 days after the onset of differentiation. The dysfunction of RPE cells is thought to be a cause of AMD.
Published in the journal Stem Cells Transitional Medicine, researchers at the University of California said that in the past techniques used to generate RPE from human pluripotent stem cells have been time consuming and inefficient.
Commenting on the discovery, James Thomson, the first researcher to isolate human embryonic stem cells, said: "RPE cells are required for visual function and are a reasonable candidate for use in cellular therapy to treat AMD. This study shows that it is now possible to produce homogeneous cultures in a shorter period of time."
Led by Drs Dennis Clegg, Peter Coffey and David Buchholz, the study was based on earlier reports that neural retinal progenitors could be generated through the application of a handful of factors.
Dr Clegg added: "As RPE and the neural retina arise from a common progenitor pool, we sought to determine whether this protocol could be altered to direct pluripotent stem cells to RPE with a similar efficiency.
"Through the combined use of the retinal inducing factors IGF1, Noggin, Dkk1 and others added at specific times, we found that pluripotent stem cells could be directed to RPE, also with an efficiency of about 80% – and it only took 14 days."