High-Resolution Imaging and Interpretation of Three-Dimensional RPE Sheet Structure

Year: 2025

Type: article

Abstract: The retinal pigment epithelium (RPE), a monolayer of pigmented cells, is critical for visual function through its interaction with the neural retina. In healthy eyes, RPE cells exhibit a uniform hexagonal arrangement, but under stress or disease, such as age-related macular degeneration (AMD), dysmorphic traits like cell enlargement and apparent multinucleation emerge. Multinucleation has been hypothesized to result from cellular fusion, a compensatory mechanism to maintain cell to cell contact, barrier function, and conserve resources in unhealthy tissue. However, traditional two-dimensional (2D) imaging using apical border markers alone may misrepresent multinucleation due to the lack of lateral markers. We present high-resolution confocal images enabling three-dimensional (3D) visualization of apical (ZO-1) and lateral (alpha-catenin) markers alongside nuclei. In two RPE damage models, we find that seemingly multinucleated cells are often single cells with displaced neighboring nuclei and lateral membranes. This emphasizes the need for 3D analyses to avoid misinterpreting multinucleation and underlying fusion mechanisms. Lastly, images from the NaIO3 oxidative damage model reveal variability in RPE damage, with elongated, dysmorphic cells showing increased ZsGreen reporter protein expression driven by EMT-linked CAG promoter activity, while more regular RPE cells displayed somewhat reduced green signal more typical of epithelial phenotypes.

Source: Biomolecules

DOI: 10.3390/biom15081084

Authors: Kevin J. Donaldson, Micah A. Chrenek, Jeffrey H. Boatright, John M. Nickerson

Institutions: Emory University, Atlanta VA Health Care System, Atlanta VA Medical Center

Language: English

Topic: Retinal Diseases and Treatments

Subfield: Ophthalmology

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $3,258

Funders: U.S. Department of Veterans Affairs, Research to Prevent Blindness, Emory University, Abraham J. and Phyllis Katz Foundation, National Institutes of Health, National Eye Institute, National Institute on Deafness and Other Communication Disorders

OpenAlex ID: W4412833361