Another Group of Stem Cell Discovered in the Human Eye
Jan 16, 2011 - Scientists from the Neural Stem Cell Institute in New York have identified a group of cells in the human eye that can be prompted to generate new retinal cells. These stem cells were found in a layer of the retina known as the retinal pigment epithelium (RPE). The RPE is a layer of cells that nourishes and protects important vision cells like the photoreceptors.
These are not the first stem cells to be detected in the human eye. Over 10 years ago, Dr. Derek van der Kooy and his team at the University of Toronto discovered stem cells around the periphery of the retina in adult mice. In 2004, with the support of Foundation Fighting Blindness donors, the team showed that these cells were also present in the human retina.
Since that time, Dr. van der Kooy and his team have worked to develop adult retinal stem cells as a treatment to repair vision loss. In 2010, they were able to restore vision to mice using this cell population.
The new group of cells discovered by Dr. Sally Temple and her New York team may also have potential for sight-restoring transplants. Unlike the cells discovered by Dr. van der Kooy, they also appear to be multipotent, which means they can form different types of tissue - not just retinal cells. This capacity may help explain some rare diseases where other types of tissue grow in the eye. It might also mean they could be used as a source of cells for transplants in other parts of the body - such as nerve cells to treat Alzheimer disease or Parkinson.
Dr. Temple's team also hopes to explore ways of stimulating the cells already in place in the retina to do a controlled repair of the retinal pigmented epithelium (RPE). This layer of cells is disrupted in conditions like age-related macular degeneration. Although repair to the RPE would not restore lost sight, it might help prevent further damage.
"I think it might be possible," Temple said, who explains that the cells have the potential to generate new tissue throughout life. "You can get these cells from a 99-year-old," she says.
"These cells are laid down in the embryo and can remain dormant for 100 years. Yet you can pull them out and put them in culture and they begin dividing. It is kind of mind boggling."
For more on this story, see this recent CTV news report.
You can learn more about this topic, for our research fact sheet on Stem Cell Therapies.