PUBLICATION

Functional rescue of REP1 following treatment with PTC124 and novel derivative PTC-414 in human choroideremia fibroblasts and the nonsense-mediated zebrafish model

Authors
Moosajee, M., Tracey-White, D., Smart, M., Weetall, M., Torriano, S., Kalatzis, V., da Cruz, L., Coffey, P., Webster, A.R., Welch, E.
ID
ZDB-PUB-160623-6
Date
2016
Source
Human molecular genetics   25(16): 3416-3431 (Journal)
Registered Authors
Keywords
none
MeSH Terms
  • Adaptor Proteins, Signal Transducing/genetics*
  • Animals
  • Apoptosis/drug effects
  • Choroideremia/drug therapy*
  • Choroideremia/genetics
  • Choroideremia/pathology
  • Codon, Nonsense
  • Disease Models, Animal
  • Fibroblasts/drug effects
  • Fibroblasts/pathology
  • Humans
  • Oxadiazoles/administration & dosage
  • Oxidative Stress/drug effects
  • Retina/drug effects
  • Retina/pathology
  • Retinal Degeneration/drug therapy*
  • Retinal Degeneration/genetics
  • Retinal Degeneration/pathology
  • Zebrafish
PubMed
27329764 Full text @ Hum. Mol. Genet.
Abstract
Choroideremia (CHM) is an X-linked chorioretinal dystrophy that is caused by mutations within a single gene, CHM Currently no effective treatment exists for these patients. Since over 30% of patients harbour nonsense mutations in CHM, nonsense suppression therapy using translational readthrough inducing drugs may provide functional rescue of REP1, thus attenuating progressive sight loss. Here, we employed two CHM model systems to systematically test the efficacy and safety of ataluren (PTC124) and its novel analog PTC-414: (1) the chmru848 zebrafish, the only nonsense mutation animal model of CHM harbouring a TAA nonsense mutation, and (2) a primary human fibroblast cell line from a CHM patient harbouring a TAG nonsense mutation. PTC124 or PTC-414 treatment of chmru848 embryos led to a ∼2.0-fold increase in survival, prevented the onset of retinal degeneration with reduced oxidative stress and apoptosis, increased rep1 protein by 23.1% (PTC124) and 17.2% (PTC-414) and restored biochemical function as confirmed through in vitro prenylation assays (98 ± 2% [PTC124] and 68 ± 5% [PTC-414]). In CHMY42X/y fibroblasts, there was a recovery of prenylation activity following treatment with either PTC124 (42 ± 5%) or PTC-414 (36 ± 11%), although an increase in REP1 protein was not detected in these cells, in contrast to the zebrafish model. This comprehensive study on the use of PTC124 and PTC-414 as successful nonsense suppression agents for the treatment of CHM highlights the translational potential of these drugs for inherited retinal disease.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping