Researchers at the Neural Stem Cell Institute (NSCI) have discovered a new adult stem cell source at the back of the human eye which, they believe, may one day aid in the repair of damage caused by age-related macular degeneration (AMD), a leading cause of vision loss in those over age 60.
Led by Dr. Sally Temple (pictured), Co-Founder and Scientific Director of the NSCI, the findings were published in the journal of the International Society for Stem Cell Research.
This new human stem cell can be isolated from the eye -- the retinal pigment epithelium stem cell (RPESC).
The retinal pigment epithelium (RPE) is a single layer of cells in the back of the eye essential for proper vision. The RPE layer is generated very early in embryonic development, leading Dr. Temple and her colleagues to test whether they possessed stem-cell-like characteristics.
They found that a small percentage of cells culture from the RPE divided prolifically and produced many new cells and shared markers of stem cells. These RPESCs seem to be silent or dormant inside the normal adult eye, but once extracted they activate and behave as stem cells.
These RPESCs were capable of making stable, healthy RPE cells. And, the RPESCs also could be turned into cells with features of neurons, bone cartilage, fat, and muscle cells.
In this study, RPESCs were isolated from all donors tested, ranging in age from 22 to 99. These cells could provide new treatment options for age-related macular degeneration (AMD) that affects more than 10 million Americans.
During AMD, RPE cells begin to die; and, as the disease progresses, typically there is significant vision loss.
Since RPESCs can re-make a pure population of RPE in the culture dish, they can potentially be used for transplantation to help repair the diseased RPE.
Studies on animal models of AMD are planned. Additionally, NSCI researchers are examining how many other nervous system cells the RPESC can produce -- for example, cells from the brain and spinal cord -- making them relevant for treating other nervous system diseases.
“The hope,” said Dr. Temple, “is that these cells can be harvested from a patient then re-injected to help repair nervous system damage, without the need for immune-suppressive therapies.”
The researchers at NSCI also are using these new RPESCs as a substrate in the culture dish for drug screening to identify new therapeutics for AMD.
Additionally, because of their ability to turn into other cell types of the brain and spinal cord, future studies will focus on whether they can become relevant to aid spinal cord injuries and for treating central nervous system diseases such as Alzheimer’s and Parkinson’s.
Illustration: Neural Stem Cell Institute.
Neural Stem Cell Institute News Release (01/06/12)
Abstract (Cell Stem Cell; Vol. 10, Issue 1, 88-95 (01/06/12))