Researchers have developed a new method for identifying retinal precursor cells derived from human embryonic stem cells (those from embryonic tissue) and induced pluripotent stem cells (those from adult skin cells). These precursor cells represent the earliest stages of retinal development. The new method results in a greater yield of retinal cells from stem cells and could be used to better understand disease processes and realize effective treatments for eye disorders.
Problems associated with retinal degenerative diseases are due to the injury and death of neurons, or support cells that can’t regenerate. The cell types primarily affected are the light-sensing rod and cone photoreceptors and the adjacent retinal pigment epithelium, which maintains proper photoreceptor health and function. If these cells could be replaced or bypassed, sight could be restored.
“So far, a number of human cell sources have been examined to see if they produce multiple retinal cell types, but most candidates have proven inadequate,” said Jason S. Meyer, PhD, at University of Wisconsin, the study’s lead author. “In comparison, human stem cells have produced cells that are clearly of a retinal nature.”
When the stem cells were isolated and matured, specific retinal cell types could be identified, including photoreceptors and retinal pigment epithelium. Using this new system, the authors could regulate the production of certain cell types by adding or removing particular compounds to the cells. “This ability could aid in the discovery of new therapeutic approaches to a variety of disorders affecting the retina,” Meyer said. “These findings could lead to treatments for other neurological disorders, in addition to eye diseases.”
“Basic neuroscience research has formed the basis for significant progress in treating eye disease,” said press conference moderator Rachel O. L. Wong, PhD, of the University of Washington, an expert on visual system development. “These studies would not be possible without technological advances and basic science research that continues to explain the normal function and development of the visual system,” Wong said.
Retinitis pigmentosa and age-related macular degeneration destroy the light-sensitive nerve cells in the retina, leading to blindness. In all, vision loss and eye disease affect 3.6 million Americans and cost the United States $68 billion each year.
Illustration: Microsoft clipart.
Society for Neuroscience Press Release (10/20/09)
Science Daily (10/21/09)
Abstract (Presented at Neuroscience 2009, the annual meeting of the Society for Neuroscience. Scientific Presentation: Sunday, Oct. 18, 8–8:15 a.m., Room S100A)