ARRA Investments in Retinitis Pigmentosa
Public Health Burden
Retinitis Pigmentosa (RP), a hereditary retinal degeneration, is a type of progressive retinal dystrophy, in which abnormalities of the photoreceptors (rods and cones) or the retinal pigment epithelium (RPE) of the retina lead to progressive visual loss in about 1:4,000 individuals world-wide. Affected individuals first experience defective dark adaptation or nyctalopia (night blindness), followed by reduction of the peripheral visual field (known as tunnel vision) and, sometimes, loss of central vision late in the course of the disease.
There are no medications, surgery or therapy that stop the evolution of the disease or that restore vision. Thus, the prognosis is poor. All treatment approaches focus on slowing the progression of the disease by protecting the eyes from sunlight, treating the complications, and helping patients cope with their vision loss.
As of yet, no widely successful treatments of RP are known. To lay the basis for possible treatments, NIH ARRA funds support basic investigations.
Understanding the transcriptional networks that regulate photoreceptor development and maintenance could enable the identification of novel targets that may be amenable for treatment strategies.
Everyday vision is highly dependent on the use of cones which contain light-sensitive visual pigments consisting of a protein component called opsin and a vitamin A derivative called 11-cis retinal. Leber Congenital Amaurosis (LCA) is an early onset eye disease where not only is synthesis of 11-cis retinal compromised such that pigments are not formed but also the cone cells degenerate rapidly after which restoration of 11-cis retinal is of no help. This proposal aims to develop chemical compounds that will prevent cones from dying in LCA.
Loss of photoreceptors through injury or disease in the human eye leads to deficits in visual function and blindness. In some animals, however, photoreceptors can regenerate from stem cells that derive from glial cells in the retina. The proposed studies use zebrafish as a genetic model to discover the molecular mechanisms that control the fate of retinal stem cells to replace photoreceptors.
Retinal degeneration, whether it is caused by retinal detachment, hereditary disease, or age, causes a dramatic rewiring of the retina that can harm the retina even before photoreceptors begin to die. Understanding the mechanisms, which cause this restructuring, could reduce these changes and help maintain normal vision for a longer period of time during retinal disease. After loss of photoreceptors, transplantation of photoreceptors may be desired. Understanding synaptic plasticity by rod and cone cells will promote successful synaptic integration of a transplant.
-- Genetic Modifiers of Photoreceptor Development and maintenance -- Haider, Neena B (NE)
-- Cone Opsin-ligand Interactions and Photoreceptor Health -- Kono, Masahiro (SC)
-- New Neurons in the Retina -- Raymond, Pamela A (MI)
-- Plasticity and Regeneration of Retinal Synapses -- Townes-Anderson, Ellen S (NJ)
Page Last Updated on June 30, 2018
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