June 2023
Volume 64, Issue 8
Open Access
ARVO Annual Meeting Abstract  |   June 2023
Optogenetic ablation of mouse retinal pigment epithelium as a model of atrophic age-related macular degeneration.
Author Affiliations & Notes
  • Glenn Yiu
    Ophthalmology & Vision Sciences, University of California Davis, Davis, California, United States
  • Brian Dang
    Ophthalmology & Vision Sciences, University of California Davis, Davis, California, United States
  • Lien Tu
    Ophthalmology & Vision Sciences, University of California Davis, Davis, California, United States
  • Iris Mollhoff
    Ophthalmology & Vision Sciences, University of California Davis, Davis, California, United States
  • Jennifer Ngo
    Ophthalmology & Vision Sciences, University of California Davis, Davis, California, United States
  • Tzu-Ni Sin
    Ophthalmology & Vision Sciences, University of California Davis, Davis, California, United States
  • Sook Hyun Chung
    Ophthalmology & Vision Sciences, University of California Davis, Davis, California, United States
  • Ratheesh Kumar Meleppat
    Ophthalmology & Vision Sciences, University of California Davis, Davis, California, United States
  • Robert J Zawadzki
    Ophthalmology & Vision Sciences, University of California Davis, Davis, California, United States
  • Footnotes
    Commercial Relationships   Glenn Yiu Abbvie, Adverum, Alimera, Bausch & Lomb, Clearside, Endogena, Genentech, Gyroscope, Intergalactic, Iridex, Janssen, Myro, NGM Bio, Novartis, Regeneron, Thea, Topcon, Zeiss. , Code C (Consultant/Contractor); Brian Dang None; Lien Tu None; Iris Mollhoff None; Jennifer Ngo None; Tzu-Ni Sin None; Sook Hyun Chung None; Ratheesh Meleppat None; Robert Zawadzki None
  • Footnotes
    Support  NIH R21 EY031108
Investigative Ophthalmology & Visual Science June 2023, Vol.64, 2732. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Glenn Yiu, Brian Dang, Lien Tu, Iris Mollhoff, Jennifer Ngo, Tzu-Ni Sin, Sook Hyun Chung, Ratheesh Kumar Meleppat, Robert J Zawadzki; Optogenetic ablation of mouse retinal pigment epithelium as a model of atrophic age-related macular degeneration.. Invest. Ophthalmol. Vis. Sci. 2023;64(8):2732.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Purpose : Geographic atrophy (GA) is a major cause of vision loss in age-related macular degeneration (AMD), but the development of new therapies has been limited by the paucity of preclinical animal models. Here, we develop a novel model of GA by photoactivating fluorescent reactive oxygen species (ROS)-generating proteins delivered to retinal pigment epithelium (RPE) mitochondria in mouse eyes to accelerate oxidative stress to trigger RPE damage and photoreceptor degeneration.

Methods : We performed subretinal injections of an AAV8 vector expressing KillerRed, mCherry, or green fluorescent protein (GFP) under an RPE-specific Bestrophin (VMD2) promoter with a mitochondrial targeting sequence into the eyes of wild-type C57BL/6J mice, then focally exposed a small square region of the retina with 561 nm light over 20 minutes at 300-700 mW using a scanning-laser ophthalmoscopy (SLO) system to activate the ROS-generating chromophores and selectively induce RPE oxidative stress. Anatomic changes were assessed longitudinally in vivo using optical coherence tomography (OCT) and ex vivo by immunostaining with antibodies to ZO-1 to assess RPE morphology on RPE flat-mounts, rhodopsin and cone arrestin to assess photoreceptor integrity on histological sections, and, TUNEL and EdU labeling to detect apoptosis and proliferation, respectively. Finally, we focally assessed photoreceptor function using OCT-based optoretinography (ORG).

Results : AAV-mediated expression of KillerRed in RPE triggered global outer retinal and RPE disruption with minimal ambient light exposure, while RPE expression of mCherry or GFP maintained normal-appearing retinal architecture at baseline. Focal photoactivation of mCherry in RPE at 561 nm triggered outer retinal and RPE atrophy resembling GA, while light delivery alone or in the presence of GFP did not produce detectable retinal damage. The focally-exposed region demonstrated reduced RPE density, rod outer segment lengths, cone density, and photoreceptor dysfunction one week after laser exposure, with some anatomic and functional recovery observed after three weeks.

Conclusions : Optogenetic ablation of mouse RPE by photoactivation of mCherry in RPE mitochondria triggers focal outer retinal and RPE atrophy in mouse eyes, and may serve as an inducible animal model of RPE oxidative stress and GA for testing novel therapies for atrophic AMD.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.

×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×