Cytochrome b5 protects photoreceptors from light stress-induced lipid peroxidation and retinal degeneration

Abstract

Neuroscience: Vision is stressful for old flies Paradoxically, light is essential for vision, yet it also induces stress that damages the sensitive cells in the eye. Vikki Weake and her team at Purdue University examined how exposure to blue light causes damage to the retina in fruit flies. Blue light causes death of photoreceptors, the light-sensing neurons. Surprisingly, very young flies are resistant to blue light. Increasing levels of a single protein, Cytochrome-b5, mimicked youthful resilience in older flies. Cytochrome-b5 is central to an ancient cellular defense system that protects membranes from oxidative damage. With expansive sensory membranes containing specialized lipids, photoreceptors are especially sensitive to membrane lipid peroxidation, an emerging final common pathway for cell death in aging and disease. Research into preventing lipid peroxidation might help to develop therapies for age-related diseases such as age-related macular degeneration.