Müller Cells May Restore Sight

by Dan Roberts
March 19, 2008
Over the past several years, scientists have been taking an interest in certain cells within the patient’s own eyes as having the potential to transform into stem-like (progenitor) cells. Called Müller glial cells, they would then migrate to damaged areas of the retina and replace dead cells, restoring vision lost to diseases like macular degeneration. Researchers at the Moorfields Eye Hospital in the U.K. have been studying the possibility of growing these cells in vitro and transplanting them back into the eye. For an abstract of their paper, see www.ncbi.nlm.nih.gov/pubmed/17525239.
Müller cells have long been known to be responsible for protecting and cleaning the retina of debris. Until now, however, it was not known what triggers their transformation into progenitor cells. On March 18, 2008, scientists at Schepens Eye Research Institute announced discovery of the chemical in the eye that is responsible. The discovery was published in the March issue of Investigative Ophthalmology and Visual Science (IOVS).
The research team, led by Dr. Dong Feng Chen (associate scientist at Schepens Eye Research Institute and Harvard Medical School) observed that the naturally occurring chemicals glutamate and aminoadipate (a derivative of glutamate) are the triggering mechanism. By injecting either of the chemicals into the eyes of healthy rats, they watched the Müller cells develop into new photoreceptors.
The next step is to test the process in animals affected by macular degeneration and retinitis pigmentosa in order to learn if vision will improve. Aminoadipate may be the chemical of choice, since it has fewer side effects than glutamate.