Led by Jeffrey Gross, PhD, the E. Ronald Salvitti Chair in Ophthalmology Research and the director of the Louis J. Fox Center for Vision Restoration, researchers are studying an unlikely creature to understand vision loss in humans: zebrafish.
A major focus area for the Department of Ophthalmology at the University of Pittsburgh School of Medicine is the regeneration of the retinal pigment epithelium and retina.
So, what is the retinal pigment epithelium? The retinal pigment epithelium, or RPE, spans the entire back of the eye and functions to maintain the health of the light-sensing photoreceptor cells of the retina; a job so important, that damage to the RPE from injury or disease leads to loss of vision. In fact, RPE dysfunction is thought to be the underlying cause of most cases of age-related macular degeneration (AMD), a leading contributor to blindness worldwide. In humans and other mammals, large RPE injury sites, such as those present in patients with advanced AMD, are unable to heal on their own, which has led to a need for research focused on RPE tissue repair.
What do fish have to do with human vision loss?
Led by Jeffrey Gross, PhD, the E. Ronald Salvitti Chair in Ophthalmology Research and the director of the Louis J. Fox Center for Vision Restoration, researchers are studying an unlikely creature to understand vision loss in humans: zebrafish. “The zebrafish is able to regrow many types of tissues after injury, including several parts of the eye,” says Dr. Gross, the Director of the Louis J. Fox Center for Vision Restoration. “The overall goal of our research is to figure out how the zebrafish repairs ocular tissue and apply that information to develop ways to promote tissue regrowth in humans.”
The research advancements
Some recent breakthroughs in the team’s research has shown that immune cells and elements of the immune response are involved in regulating RPE repair in zebrafish, allowing scientists to focus their efforts on understanding how these specific immune-related signals play a role in this RPE repair. Additionally, by studying Müller glia, the major cell type in the retina, researchers know that while humans and zebrafish can both experience similar damage to the retina, Müller glia in fish have an evolutionarily conserved stem cell potential which enables it to generate new retinal neurons after the injury. This regenerative response is dictated by specific DNA regions in the genetic makeup of the fish. Dr. Gross and his team are now focused on what “triggers” this phenomenon and how a similar response may be achieved in humans.
“Our hope is that these findings will contribute to the large body of ongoing research aimed at repairing RPE tissue, with the long-term goal of slowing or reversing blinding diseases such as AMD,” states Dr. Gross.