Interdisciplinary Graduate Program
Department of Ophthalmology; Gene Therapy Center
Eye Diseases | Genetics and Genomics | Neuroscience and Neurobiology | Ophthalmology
Retinitis pigmentosa (RP) is an inherited photoreceptor degenerative disorder that results in blindness. The disease is often caused by mutations in genes that are specific to rod photoreceptors; however, blindness results from the secondary loss of cones by a still unknown mechanism. Here, we demonstrated that the mammalian target of rapamycin complex 1 (mTORC1) is required to slow the progression of cone death during disease and that constitutive activation of mTORC1 in cones is sufficient to maintain cone function and promote long-term cone survival. Activation of mTORC1 in cones enhanced glucose uptake, retention, and utilization, leading to increased levels of the key metabolite NADPH. Moreover, cone death was delayed in the absence of the NADPH-sensitive cell death protease caspase 2, supporting the contribution of reduced NADPH in promoting cone death. Constitutive activation of mTORC1 preserved cones in 2 mouse models of RP, suggesting that the secondary loss of cones is caused mainly by metabolic deficits and is independent of a specific rod-associated mutation. Together, the results of this study address a longstanding question in the field and suggest that activating mTORC1 in cones has therapeutic potential to prolong vision in RP.
Genetics, Neuroscience, Ophthalmology
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Copyright © 2015, The American Society for Clinical Investigation. Publisher PDF posted as allowed by the publisher's author rights policy at http://content-assets.jci.org/admin/forms/jcicopyright.pdf.
DOI of Published Version
J Clin Invest. 2015 Apr;125(4):1446-58. doi: 10.1172/JCI79766. Epub 2015 Mar 23. Link to article on publisher's site
The Journal of clinical investigation
Venkatesh A, Ma S, Le YZ, Hall MN, Ruegg MA, Punzo C. (2015). Activated mTORC1 promotes long-term cone survival in retinitis pigmentosa mice. GSBS Student Publications. https://doi.org/10.1172/JCI79766. Retrieved from https://escholarship.umassmed.edu/gsbs_sp/1901