Journal article
Sialoglycoconjugate profiling of human choroid, retinal pigment epithelium, and basal laminar deposits
Experimental eye research, Vol.260, 110618
11/01/2025
DOI: 10.1016/j.exer.2025.110618
PMCID: PMC12629097
PMID: 40889610
Abstract
Age-related macular degeneration is a leading cause of central vision loss in the elderly. Early hallmarks of the disease include basal laminar deposit beneath the retinal pigment epithelium (RPE) and choriocapillaris degeneration. We utilized sialic acid binding lectins Sambucus nigra/Elderberry Bark Lectin (EBL) and Maackia amurensis lectin II (MAL-II), to assess the localization of ɑ-2,6 and ɑ-2,3 sialic acids, respectively, in human macular retina, RPE, basal laminar deposits, and choroid. Photoreceptor carbohydrate epitopes differ based on retinal topography, with MAL-II recognizing foveal (but not extrafoveal) cones. Both MAL-II and EBL react with apical RPE, and both bind basal laminar deposits. In the choroid, MAL-II predominantly labels the choriocapillaris endothelium, while EBL also shows robust labeling of Bruch's membrane and extracellular domains surrounding the microvasculature (intercapillary pillars). EBL labeling overlaps with the distribution of complement factor H to a greater extent than MAL-II. After treatment with neuraminidase to remove terminal sialic acids, a battery of lectins was applied to sections of choroids. Lectins that recognize β-galactose, N-acetyllactosamine, galactose (β-1,3) N-acetylgalactosamine, and ɑ- or β-N-acetylgalactosamine showed increased reactivity, indicating the presence of abundant sialoglycans in basal laminar deposits. This study provides insight into the location and partial identities of sialoglycoconjugates in the human choroid, with possible implications for understanding the pathogenesis of macular degeneration.
Details
- Title: Subtitle
- Sialoglycoconjugate profiling of human choroid, retinal pigment epithelium, and basal laminar deposits
- Creators
- Emma M Navratil - University of IowaPiper A Wenzel - University of IowaMiles J Flamme-Wiese - University of IowaJack E B MillerLuke A Wiley - University of IowaEdwin M Stone - University of IowaBudd A Tucker - University of IowaRobert F Mullins - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Experimental eye research, Vol.260, 110618
- DOI
- 10.1016/j.exer.2025.110618
- PMID
- 40889610
- PMCID
- PMC12629097
- NLM abbreviation
- Exp Eye Res
- ISSN
- 0014-4835
- eISSN
- 1096-0007
- Publisher
- ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD
- Grant note
- NIH: EY-024605, EY-033308, P30 EY025580, T32GM145441 Elmer and Sylvia Sramek Charitable Trust
Funding statement This work was supported by NIH grants EY-024605, EY-033308, P30 EY025580, T32GM145441, and the Elmer and Sylvia Sramek Charitable Trust.
- Language
- English
- Date published
- 11/01/2025
- Academic Unit
- The University of Iowa Institute for Vision Research; Iowa Neuroscience Institute; John and Marcia Carver Nonprofit Genetic Testing Laboratory; Neuroscience and Pharmacology; Ophthalmology and Visual Sciences
- Record Identifier
- 9984958293702771
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