Experimental Approaches to the Study of A2E, a Bisretinoid Lipofuscin Chromophore of Retinal Pigment Epithelium

Bisretinoid lipofuscin compounds that accumulate in retinal pigment epithelial (RPE) cells are implicated in the pathogenesis of some forms of macular degeneration. In the development of approaches to the amelioration of retinal disorders characterized by enhanced RPE lipofuscin formation, attention is being given to therapies that reduce the production of these damaging pigments. An understanding of the biosynthetic pathways by which these molecules form is essential to the development of these therapies. Thus methods for studying the biosynthesis of these compounds are presented. A tissue culture model is also described whereby a human RPE cell line that is otherwise devoid of bisretinoid lipofuscin compounds is employed and synthesized A2E is delivered to the cells. This approach allows for a population of RPE cells that have accumulated the lipofuscin fluorophore A2E in addition to A2E-free cells.