Macular degeneration and retinitis pigmentosa being targeted
A research study at the University of Nebraska Medical Center shows promise that adult stem cells within the retina can be chemically induced to regenerate photoreceptors and restore vision in people suffering from conditions such as age-related macular degeneration (AMD) and retinitis pigmentosa (RP).
The research, which was done on mice and rats, is reported in the Aug. 26 edition of PLoS One, a leading science journal through the Public Library of Science.
The research represents the first indication that the retina can be repaired from within by its own cells. It would be a significant departure from transplantation of stem cells, which is now being studied for restoring lost vision. Retinal transplantation is an invasive procedure that brings with it a variety of concerns such as immune rejection and the source of cells.
“This is really exciting,” said Iqbal Ahmad, Ph.D., professor of ophthalmology and visual sciences for UNMC and the lead investigator on the study. “It’s a tantalizing stem cell approach to correct vision loss…to harness existing stem cells and coax them into repairing the retina.
“Before, stem cell transplantation was regarded to be the only practical way to restore vision. This is a radically different approach, and best of all, it is relatively safe and free from controversy.”
The degeneration of photoreceptors, cells in the retina that capture light, is the cause of vision loss in AMD and RP. Unfortunately, there is no treatment for photoreceptor degeneration.
In the study, which spanned four years, Dr. Ahmad and his team, led by Carolina Del Debbio, Ph.D., a postdoctoral associate, activated the adult stem cells taken from the retina with a combination of chemicals and peptides.
A small proportion of the activated stem cells migrated to the location of dying photoreceptors and differentiated into photoreceptor-like cells. These cells expressed proteins that are exclusively expressed by photoreceptors and help capture light.
An accompanying result was that rats that were chemically treated demonstrated a transient but significant improvement in light perception. Preliminary results suggest that the improvement in light perception is likely due to the regeneration of photoreceptors, but further studies are needed to confirm it, Dr. Ahmad said.
“We next need to learn how to increase the efficiency of activating cells and making them photoreceptors,” Dr. Ahmad said.
Through world-class research and patient care, UNMC generates breakthroughs that make life better for people throughout Nebraska and beyond. Its education programs train more health professionals than any other institution in the state. Learn more at unmc.edu.