Looking Chloride Channels Straight in the Eye: Bestrophins, Lipofuscinosis, and Retinal Degeneration

Abstract

Recent evidence suggests that Cl⁻ ion channels are important for retinal integrity. Bestrophin Cl⁻ channel mutations in humans are genetically linked to a juvenile form of macular degeneration, and disruption of some ClC Cl⁻ channels in mice leads to retinal degeneration. In both cases, accumulation of lipofuscin pigment is a key feature of the cellular degeneration. Because Cl⁻ channels regulate the ionic environment inside organelles in the endosomal-lysosomal pathway, retinal degeneration may result from defects in lysosomal trafficking or function.