Purpose - To determine the feasibility of introducing the gene for human catalase into the guinea pig eye by viral mediated transfer. Catalase is an antioxidant enzyme that detoxifies hydrogen peroxide that is generated by the dismutation of superoxide. Methods - We injected 50 μl of the replication-deficient adenoviral catalase cDNA into the vitreous cavity of anesthetized strain-13 guinea pigs. We performed weekly in vivo fundus photographs of the retina and optic nerve head of each guinea pig eye to look for intraocular inflammation. For evaluation of transgene expression the animals were overdosed with pentobarbital at 4 weeks after the intravitreal injection. Animals were perfused with 4% paraformaldehyde then the globes were dissected out and processed for cryomicrotomy. Immunostaining with rabbit antibodies against catalase was followed by staining with goat anti-rabbit antibodies conjugated to 5 nm colloidal gold, then detected by silver enhancement for light microscopic visualization. The contralateral eyes served as negative controls for immunolabeling. Results - Weekly fundus photographs taken 1-4 weeks after the intravitreal injections showed no inflammation in eyes that received the replication-deficient adenoviral catalase cDNA. Light microscopy revealed cell specific immunolabeling for catalase predominantly in the ganglion cell and inner nuclear layers of the retina. Choroidal blood vessels were also immunolabeled. Control eyes showed no immunolabeling. Conclusions - The successful ocular expression of catalase paves the way for future study of the effects of gene therapy to reduce oxidative injury associated with ocular inflammation, ischemia and phototoxicity.
|Journal||Investigative Ophthalmology and Visual Science|
|Publication status||Published - 15 Feb 1996|
ASJC Scopus subject areas
- Sensory Systems
- Cellular and Molecular Neuroscience