A number of prevalent and currently incurable eye diseases are caused by aberrant oxidative and/or unfolded protein stress. In healthy individuals, these stresses are mitigated by the activation of stress-responsive signaling pathways such as the oxidative stress response and the unfolded protein response. After the cellular stress has been remedied, signaling through these pathways returns to basal levels. However, as an individual ages, or in the case of specific inherited mutations, the ability to effectively recognize stress and activate the appropriate signaling pathways declines5, in many instances resulting in prevalent diseases such as dry age-related macular degeneration (AMD). Thus, one approach to treat stress- related ocular diseases such as AMD would be to restore the appropriate stress-responsive signaling pathways in the eye. However, the technical capability to re-establish this signaling in a physiological context (i.e., conditional sinusoidal expression) in the eye is lacking. Therefore, there is an urgent need to develop a conditional and reversible therapeutic strategy that allows experimental control of the timing and extent of expression of a gene of interest (i.e., a stress- responsive transcription factor) in the eye. Towards this end, in this exploratory/developmental project, we will use adeno-associated virus (AAV) to introduce a small molecule-regulated destabilized domain (DD) strategy to conditionally control protein abundance using mice as a model system. The expected outcomes of this R21 project are to i) validate the use of DD technology for controlling protein levels in the eye in aged mice and ii) to test whether DDs can be used in retinal cells already undergoing degeneration/atrophy. These findings will be critical to determine whether this promising, and potentially broadly applicable DD strategy can be adapted to future research projects targeted at modulating or restoring stress-responsive signaling pathways in the eye. Therefore, successful completion of this project will ultimately positively impact the treatment of currently incurable age-related and inherited eye diseases.
Destabilized domains (DDs) allow for conditional regulation of a protein of interest via a small molecule. They have been successfully used in a wide variety of organisms and bodily tissues to prevent disease-associated phenotypes, but have never been applied toward the treatment of eye disease. This project will explore whether DDs can be effectively used to control protein abundance in both aged and diseased mouse retinas, thereby providing justification to pursue DD-based approaches for ultimately treating a number of age-related and inherited retinal disorders.
| Datta, Shyamtanu; Renwick, Marian; Chau, Viet Q et al. (2018) A Destabilizing Domain Allows for Fast, Noninvasive, Conditional Control of Protein Abundance in the Mouse Eye - Implications for Ocular Gene Therapy. Invest Ophthalmol Vis Sci 59:4909-4920 |
