April 18, 2013 -- Controlling the differentiation of human pluripotent stem cells is the goal of many laboratories, both to study normal human development and to generate cells for transplantation in treating various diseases and conditions. RPE (retinal pigmented epithelial) is one important cell type under investigation as it protects and nourishes the photoreceptors and is vital in maintaining healthy eyesight.
In fact, the dysfunction and death of RPE is thought to be behind the leading cause of blindness in the Western world — age related macular degeneration.
Transplantation of RPE cells into the retina to treat AMD has been demonstrated in animals and is now being tested in clinical trials in humans. However, protocols to generate RPE from human pluripotent stem cells are time consuming and relatively inefficient. But a team of scientists at the University of California, Santa Barbara, reports in the latest issue of STEM CELLS Translational Medicine that it has found a way to isolate RPE cells as early as 14 days following the onset of differentiation.
"RPE cells are required for visual function and are a reasonable candidate for use in cellular therapy to treat macular degeneration. This study shows that it is now possible to produce homogeneous cultures in a shorter period of time," said James Thomson, a Wisconsin-based researcher who was the first to isolate human embryonic stem cells, commenting on the study.
The UCSB research team was led by Dennis Clegg, Ph.D., Peter Coffey, Ph.D., and David Buchholz, Ph.D. They based their study on earlier reports that neural retinal progenitors could be generated through the application of a handful factors.
“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,” Dr. Clegg explained. “Through the combined use of the retinal inducing factors IGF1, Noggin, Dkk1, bFGF and other factors added at specific times, we found that pluripotent stem cells could be directed to RPE, also with an efficiency of about 80 percent — and it only took 14 days. ”
“Protocols currently being used to generate RPE cells take months; this protocol should be useful for quickly generating quantities of RPE cells for transplantation as well as for the study of RPE development,” Dr. Buchholz added.
“This report is important because stem cell derived RPE are currently in clinical trials for the treatment of age related macular degeneration and Stargardt disease,” said Anthony Atala, M.D., Editor of STEM CELLS Translational Medicine and director of the Wake Forest Institute for Regenerative Medicine. “The protocol could prove useful for rapidly generating banks of cells for treating these conditions.”
About STEM CELLS Translational Medicine: STEM CELLS TRANSLATIONAL MEDICINE (SCTM), published by AlphaMed Press, is a monthly peer-reviewed publication dedicated to significantly advancing the clinical utilization of stem cell molecular and cellular biology. By bridging stem cell research and clinical trials, SCTM will help move applications of these critical investigations closer to accepted best practices.
About AlphaMed Press: Established in 1983, AlphaMed Press with offices in Durham, NC, San Francisco, CA, and Belfast, Northern Ireland, publishes two other internationally renowned peer-reviewed journals: STEM CELLS® (www.StemCells.com), in its 31st year, is the world's first journal devoted to this fast paced field of research. The Oncologist® (www.TheOncologist.com), also a monthly peer-reviewed publication, entering its 18th year, is devoted to community and hospital-based oncologists and physicians entrusted with cancer patient care. All three journals are premier periodicals with globally recognized editorial boards dedicated to advancing knowledge and education in their focused disciplines.