Regeneration of the zebrafish retinal pigment epithelium after widespread genetic ablation

• Published in: PLoS genetics 2019-01, Vol.15 (1), p.e1007939-e1007939
• Main Authors: Hanovice, Nicholas J, Leach, Lyndsay L, Slater, Kayleigh, Gabriel, Ana E, Romanovicz, Dwight, Shao, Enhua, Collery, Ross, Burton, Edward A, Lathrop, Kira L, Link, Brian A, Gross, Jeffrey M
• Format: Article
• Language: English
• Subjects: Age; Animal genetic engineering; Animals; Animals, Genetically Modified - genetics; Animals, Genetically Modified - growth & development; Apoptosis; Apoptosis - genetics; Biology and Life Sciences; Bruch Membrane - growth & development; Bruch Membrane - metabolism; Cell Differentiation - genetics; Cell proliferation; cis-trans-Isomerases - genetics; Danio rerio; Degenerative diseases; Disease Models, Animal; Epithelium; Genetic aspects; Genetic engineering; Green Fluorescent Proteins - genetics; Humans; Imides - administration & dosage; Larva - genetics; Larva - growth & development; Macular degeneration; Macular Degeneration - genetics; Macular Degeneration - pathology; Medicine; Medicine and Health Sciences; Neurobiology; Neurosciences; Photoreceptor Cells - metabolism; Photoreceptor Cells - pathology; Photoreceptors; Physiological aspects; Quinolines - administration & dosage; Regeneration (Biology); Regeneration - genetics; Research and Analysis Methods; Retina; Retina - growth & development; Retina - pathology; Retinal pigment epithelium; Retinal Pigment Epithelium - growth & development; Retinal Pigment Epithelium - metabolism; Social Sciences; Visual perception; Visual system; Wnt protein; Wnt Signaling Pathway - drug effects; Zebrafish; Zebrafish - genetics; Zebrafish - growth & development
• ISSN: 1553-7404; 1553-7390; 1553-7404
• DOI: 10.1371/journal.pgen.1007939

The retinal pigment epithelium (RPE) is a specialized monolayer of pigmented cells within the eye that is critical for maintaining visual system function. Diseases affecting the RPE have dire consequences for vision, and the most prevalent of these is atrophic (dry) age-related macular degeneration (AMD), which is thought to result from RPE dysfunction and degeneration. An intriguing possibility for treating RPE degenerative diseases like atrophic AMD is the stimulation of endogenous RPE regeneration; however, very little is known about the mechanisms driving successful RPE regeneration in vivo. Here, we developed a zebrafish transgenic model (rpe65a:nfsB-eGFP) that enabled ablation of large swathes of mature RPE. RPE ablation resulted in rapid RPE degeneration, as well as degeneration of Bruch's membrane and underlying photoreceptors. Using this model, we demonstrate for the first time that zebrafish are capable of regenerating a functional RPE monolayer after RPE ablation. Regenerated RPE cells first appear at the periphery of the RPE, and regeneration proceeds in a peripheral-to-central fashion. RPE ablation elicits a robust proliferative response in the remaining RPE. Subsequently, proliferative cells move into the injury site and differentiate into RPE. BrdU incorporation assays demonstrate that the regenerated RPE is likely derived from remaining peripheral RPE cells. Pharmacological disruption using IWR-1, a Wnt signaling antagonist, significantly reduces cell proliferation in the RPE and impairs overall RPE recovery. These data demonstrate that the zebrafish RPE possesses a robust capacity for regeneration and highlight a potential mechanism through which endogenous RPE regenerate in vivo.