A ground breaking study has, for the first time, identified how cone photoreceptor cells die, leading to Retinis Pigmentosa (RP).
The study, conducted at the Massachusetts Eye and Ear Infirmary, found that receptor interacting protein (RIP) kinase mediated necrosis is involved in cone degeneration. Treatment with a drug that inhibits RIP kinase significantly delayed cone cell death and preserved cone photoreceptors.
Retinitis pigmentosa is an inherited condition that causes irreversible vision loss due to the degeneration of photoreceptor cells in the eye called “rods” and “cones”. Rods are responsible for night vision, while cones are responsible for daylight and central vision. Vision loss from RP often begins with loss of night vision, due to death of rods, followed by loss of peripheral and central vision, due to death of rods and cones. Such vision loss can have a significant impact on people’s daily lives, such as affecting their ability to read or drive a car. RP affects more than one million people around the world.
Research conducted by Dr. Eliot L. Bersonof the Berman-Gund Laboratory for the Study of Retinal Degenerations at Massachusetts Eye and Ear, has shown that while Vitamin A supplementation and an omega-3 rich diet can slow visual decline resulting from RP; they do not completely stop disease progression. For most patients, RP results in irreversible vision loss.
Previous studies have identified mutations in more than 50 genes that cause RP, but the mechanisms by which rods and cones die remained to be completely defined
Previous studies have identified mutations in more than 50 genes that cause RP, but the mechanisms by which rods and cones die remained to be completely defined. Since many of the genes associated with RP produce proteins that are used specifically in rod cells, why and how cones, which in some cases do not use the mutant proteins, die after rods degenerate remained unclear.
“Though the precise mechanisms involved in RIP kinase inducing necrosis remain unknown, our finding that necrosis results in cone cell death puts us one step closer to understanding this disease and, more importantly, moves us one step closer to being able to provide novel therapies to millions of patients with vision loss,” said Professor Demetrios G. Vavvas, who led the research team.
The study was published in the Proceedings of the National Academy of Sciences Early Edition.
