Jillian N. Pearring, PhD
Assistant Professor, Ophthalmology and Visual Sciences, Kellogg Eye Center University of Michigan
Research: “Photoreceptor Outer Segment Regeneration: Understanding the Molecular Programs and Dynamic Cellular Processes”
Research
Photoreceptor Outer Segment Regeneration: Understanding the Molecular Programs and Dynamic Cellular ProcessesThe Pearring laboratory studies the molecular and cellular mechanisms of vision with a focus on the light-sensing cells of the retina, the photoreceptors. Photoreceptors are a polarized neurons in which specific processes are carried out in highly specialized subcellular compartments. The distal rod- or cone-shaped outer segment compartment captures photons of light and initiates the light response. The outer segment is a modified primary cilium with a unique architecture: it contains hundreds of tightly stacked, disc-shaped membranes that are densely packed with the GPCR photopigment to maximize light sensitivity. This modification results in a photoreceptor cilium that is over 50-fold larger than a normal primary cilium. One by-product of light absorption is photo-oxidative damage, which the photoreceptor cell overcomes by continuously replacing its ciliary outer segment on a daily basis. Like a conveyer belt, outer segment renewal occurs by adding new protein and lipid material to nascent discs at the base, while old discs at the distal tip are consumed by retinal pigment epithelium cells. A common phenotype shared during retinal injury and inherited retinal diseases is degeneration of the outer segment followed by photoreceptor cell death. Thus, understanding the underlying mechanisms governing outer segment renewal will provide valuable insight into how to regenerate this light-sensing organelle following injury or disease.
