Using pluripotent cells similar to stem cells, an international team of scientists has rescued visual function in laboratory rats with eye disease.
The research shows the potential for stem cell-based therapies to treat age-related macular degeneration in humans.
Led by Dennis Clegg of the University of California, Santa Barbara, and Pete Coffey (University College London), published their work in two papers, including one published this week in the journal PloS One.
The first paper was published in the October 27 issue of the journal Stem Cells.
The scientists worked with rats that have a mutation which causes a defect in retinal pigmented epithelial (RPE) cells and leads to photoreceptor death and subsequent blindness.
Human RPE cells were derived from induced pluripotent stem cells, which are embryonic stem cell-like cells that can be made from virtually any cell in the body, avoiding the controversy involved in using stem cells derived from embryos.
Pluripotent means that the cells can become almost any cell in the body.
In experiments done by UCL's Amanda Carr, the team found that by surgically inserting stem cell-derived RPE into the retinas of the rats before photoreceptor degeneration, vision was retained.
They found that the rats receiving the transplant tracked their visual focus in the direction of moving patterns more efficiently than control groups that did not receive a transplant.
"Although much work remains to be done, we believe our results underscore the potential for stem-cell based therapies in the treatment of age-related macular degeneration," said Sherry Hikita, an author on both papers and director of UCSB's Laboratory for Stem Cell Biology.
Dave Buchholz, first author of the article in Stem Cells, said that by using induced stem cells that can be derived from patients, the scientists avoid immune rejection that might occur when using embryonic stem cells.
"RPE cells are essential for visual function," Buchholz said. "Without RPE, the rod and cone photoreceptors die, resulting in blindness. This is the basic progression in age-related macular degeneration. The hope is that by transplanting fresh RPE, derived from induced pluripotent stem cells, the photoreceptors will stay healthy, preventing vision loss."