PUBLICATION

Transgenic Overexpression of Myocilin Leads to Variable Ocular Anterior Segment and Retinal Alterations Associated with Extracellular Matrix Abnormalities in Adult Zebrafish

Authors
Atienzar-Aroca, R., Ferre-Fernández, J.J., Tevar, A., Bonet-Fernández, J.M., Cabañero, M.J., Ruiz-Pastor, M.J., Cuenca, N., Aroca-Aguilar, J.D., Escribano, J.
ID
ZDB-PUB-220911-11
Date
2022
Source
International Journal of Molecular Sciences   23(17): (Journal)
Registered Authors
Atienzar-Aroca, Raquel, Bonet-Fernández, Juan-Manuel, Cabañero-Valera, María-José, Escribano Martínez, Julio, Tevar-Saiz, Angel
Keywords
anterior segment alterations, matricellular protein, myoc, myocilin, retinal dysplasia, transgenic myoc, zebrafish
MeSH Terms
  • Animals
  • Cytoskeletal Proteins
  • Extracellular Matrix/metabolism
  • Eye Abnormalities*
  • Eye Proteins/genetics
  • Eye Proteins/metabolism
  • Glycoproteins/genetics
  • Glycoproteins/metabolism
  • Hypertrophy
  • Male
  • Mice
  • Mice, Transgenic
  • Retina/metabolism
  • Zebrafish*/genetics
  • Zebrafish*/metabolism
PubMed
36077382 Full text @ Int. J. Mol. Sci.
Abstract
Myocilin is an enigmatic glaucoma-associated glycoprotein whose biological role remains incompletely understood. To gain novel insight into its normal function, we used transposon-mediated transgenesis to generate the first zebrafish line stably overexpressing myocilin [Tg(actb1:myoc-2A-mCherry)]. qPCR showed an approximately four-fold increased myocilin expression in transgenic zebrafish embryos (144 hpf). Adult (13 months old) transgenic animals displayed variable and age-dependent ocular anterior segment alterations. Almost 60% of two-year-old male, but not female, transgenic zebrafish developed enlarged eyes with severe asymmetrical and variable abnormalities in the anterior segment, characterized by corneal limbus hypertrophy, and thickening of the cornea, iris, annular ligament and lens capsule. The most severe phenotype presented small or absent ocular anterior chamber and pupils, due to iris overgrowth along with dysplastic retinal growth and optic nerve hypertrophy. Immunohistochemistry revealed increased presence of myocilin in most altered ocular tissues of adult transgenic animals, as well as signs of retinal gliosis and expanded ganglion cells and nerve fibers. The preliminary results indicate that these cells contributed to retinal dysplasia. Visual impairment was demonstrated in all old male transgenic zebrafish. Transcriptomic analysis of the abnormal transgenic eyes identified disrupted expression of genes involved in lens, muscular and extracellular matrix activities, among other processes. In summary, the developed transgenic zebrafish provides a new tool to investigate this puzzling protein and provides evidence for the role of zebrafish myocilin in ocular anterior segment and retinal biology, through the influence of extracellular matrix organization and cellular proliferation.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping