Abstract
Purpose :
Cataracts are one of the leading causes of vision loss in humans. Genetically or chemically induced cataracts in animal models have been used for many years in research, however, models with naturally developing nuclear cataracts are lacking. High rates of naturally occurring cataracts are observed in lumpfish (Cyclopterus lumpus L.) both in the wild and particularly in cultured populations. Lumpfish are widely used as cleaner fish in the commercial farming of Atlantic salmon (Salmo salar) and they rely on their vision to locate and consume their food. 4-hydroxynonenal (4-HNE) and 8-hydroxyguanine (8-OH-G) are markers of oxidative stress which result from lipid peroxidation and nucleic acid oxidation, respectively. 4-HNE and 8-OH-G have been found in elevated amounts in cataractous eyes of humans and several other chemically or genetically induced animal models of cataract. The aim is to determine the difference in levels of 4-HNE and 8-OH-G in cataractous and non-cataractous lumpfish eyes. Characterizing the expression of proven biomarkers of cataract development in lumpfish may help to establish cultured lumpfish as a model for studying the natural pathogenesis of human cataracts.
Methods :
Paraffin embedded specimens of cultured lumpfish eyes with and without cataracts were sectioned and mounted on slides. The slides were stained by immunohistochemistry with either 4-HNE or 8-OH-G antibodies. Immunostaining intensities in lens epithelium images were determined using ImageJ software.
Results :
Cataractous eyes stained with 4-HNE as well as 8-OH-G showed a significantly higher level of staining when compared with normal eyes. The staining intensity (%) of eyes stained with 4-HNE was 4.9 times higher in eyes with cataracts versus normal eyes (p<0.0001). Similarly, the staining intensity (%) of eyes stained with 8-OH-G was 4.5 times higher in cataractous eyes versus normal eyes (p=0.0077).
Conclusions :
There is a positive correlation between the presence of cataracts and the increased expression of 4-HNE and 8-OH-G in lumpfish lenses. With further characterization, lumpfish could represent a good model for studying the natural pathogenesis of cataracts in humans.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.