Translational bypass of nonsense mutations in zebrafish rep1, pax2.1 and lamb1 highlights a viable therapeutic option for untreatable genetic eye disease

Moosajee, M., Gregory-Evans, K., Ellis, C.D., Seabra, M.C., and Gregory-Evans, C.Y.
Human molecular genetics   17(24): 3987-4000 (Journal)
Registered Authors
MeSH Terms
  • Adaptor Proteins, Signal Transducing/biosynthesis
  • Adaptor Proteins, Signal Transducing/genetics*
  • Animals
  • COS Cells
  • Chlorocebus aethiops
  • Codon, Nonsense/genetics*
  • Disease Models, Animal
  • Dose-Response Relationship, Drug
  • Embryo, Nonmammalian/drug effects
  • Embryo, Nonmammalian/physiology
  • Eye Diseases, Hereditary/drug therapy*
  • Eye Diseases, Hereditary/embryology
  • Eye Diseases, Hereditary/genetics*
  • Gene Expression Regulation, Developmental/drug effects
  • Gentamicins/pharmacology
  • Gentamicins/toxicity
  • Laminin/biosynthesis
  • Laminin/genetics*
  • PAX2 Transcription Factor/biosynthesis
  • PAX2 Transcription Factor/genetics*
  • Paromomycin/pharmacology
  • Paromomycin/toxicity
  • Phenotype
  • Protein Biosynthesis/drug effects
  • Protein Biosynthesis/genetics*
  • Protein Synthesis Inhibitors/pharmacology
  • Zebrafish/genetics
  • Zebrafish Proteins/biosynthesis
  • Zebrafish Proteins/genetics*
18809619 Full text @ Hum. Mol. Genet.
The extensive molecular genetic heterogeneity seen with inherited eye disease is a major barrier to the development of gene-based therapeutics. The underlying molecular pathology in a considerable proportion of these diseases however are nonsense mutations leading to premature termination codons. A therapeutic intervention targeted at this abnormality would therefore potentially be relevant to a wide range of inherited eye diseases. We have taken advantage of the ability of aminoglycoside drugs to suppress such nonsense mutations and partially restore full-length, functional protein in a zebrafish model of choroideraemia (chm(ru848); juvenile chorio-retinal degeneration) and in two models of ocular coloboma (noi(tu29a) and gup(m189); congenital optic fissure closure defects). In vitro cell-based assays showed significant readthrough with two drugs, gentamicin and paromomycin, which was confirmed by Western blot and in vitro prenylation assays. Presence of either aminoglycoside during zebrafish development in vivo showed remarkable prevention of mutant ocular phenotypes in each model and a reduction in multisystemic defects leading to a 1.5-1.7 fold increase in survival. We also identified a significant reduction in abnormal cell death shown by TUNEL assay. To test the hypothesis that optic fissure closure was apoptosis-dependent, the anti-apoptotic agents, curcumin and zVAD-fmk, were tested in gup(m189) embryos. Both drugs were found to reduce the size of the coloboma, providing molecular evidence that cell death is required for optic fissure remodelling. These findings draw attention to the value of zebrafish models of eye disease as useful pre-clinical drug screening tools in studies to identify molecular mechanisms amenable to therapeutic intervention.
Genes / Markers
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Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Engineered Foreign Genes