Abstract
Purpose: :
To create a rodent model for Type II Macular telangiectasia (MacTel), a retinal disease characterized by vascular leakage, proliferation of blood vessels, the formation of cavities and the loss of visual acuity. The disease pathogenesis is poorly understood. We hypothesize that MacTel’s pathogenesis could involve the demise of Müller cells, the primary glial cell type in the retina.
Methods: :
To test this hypothesis, we constructed a plasmid containing the KillerRed gene downstream of a viral CAG promoter. KillerRed is a fluorescent protein whose toxicity is inducible. We then packaged it into the ShH10-Y445F adeno-associated virus, a novel variant of AAV6 with high infection specificity for retinal Müller cells, and delivered it intravitreally to four mice, using ShH10 packaged with GFP as a control. After regulated sessions of irradiation with green light, we compared the KillerRed-treated eye with the control using optical coherence tomography (OCT), electroretinography (ERG), fluorescein angiography, and visualization of retinal vasculature with a lipophilic carbocyanide dye.
Results: :
When we transfected the KillerRed plasmid into Müller cell culture and Hek293 T cell culture, irradiation with bright green light results in cell death after twenty minutes, compared to no cell death when transfected with GFP. KillerRed expression has been confirmed in rodents’ eyes with cryosectioning and histology. In eyes injected with KillerRed, OCT data indicates retinal thinning and structural damage, while ERG data suggests compromised light transduction.
Conclusions: :
Preliminary results indicate that eliminating Muller cells in the retina results in damage to the retina’s structure and visual acuity. Further research is needed to determine effects of KillerRed on the retina’s vasculature.
Keywords: macular holes • retinal degenerations: cell biology • retinal neovascularization