by Dan Roberts
A research team at the University of California, San Diego (UCSD) School of Medicine and the University of Utah have developed a mouse model of Age-Related Macular Degeneration (AMD) and Stargardt’s disease. As reported in the online edition of the Proceedings of the National Academy of Sciences (March 4, 2005), the mouse model is the first to replicate the symptoms of the most common form (dry) of age-related macular degeneration and of Stargardt’s disease, a juvenile form of the disease. Another mouse model has been developed for Stargardt’s to study a mutated form of the ABCR4 gene, but that model does not display retinal degeneration.
This mouse model displays significant accumulation of lipofuscin (debris accumulated in the retinal pigment epithelium, or RPE) as a result of a mutation in the gene called ELOVL4, which has been found to be common to both conditions in humans. Accumulation of lipofuscins in the retina inhibits nourishment of the photoreceptor cells by the RPE, resulting in degeneration and vision loss. The development of a mouse model will allow researchers to now test potential therapies for both dry ARMD and Stargardt’s disease in an animal–a practice that has not been possible in the past.
Co-senior authors of the study were David S. Williams, Ph.D. (UCSD professor of pharmacology and neurosciences) and Kang Zhang (Department of Ophthalmology and Visual Science, Program in Human Molecular Biology and Genetics, Eccles Institute of Human Genetics and Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, Utah). Co-first authors of the paper were G. Karan, (University of Utah) and C. Lillo (UCSD Departments of Pharmacology and Neurosciences). Additional authors were D. J. Cameron, Yu Zhao, and C. Li (University of Utah), H. R. Vollmer-Snarr (UCSD), and K.G. Locke and D.G. Birch (Brigham Young University, Provo, Utah).