The proposed study is a five-year career development research plan that focuses on dissecting the epigenetic regulation of retinal ganglion cell (RGC) degeneration and regeneration in mouse models of optic nerve crush and glaucoma. The candidate is currently a postdoctoral research fellow at F.M. Kirby Neurobiology Center at Boston Children?s Hospital and Harvard Medical School. The candidate intends to further extend his expertise in epigenomic profiling technologies, mechanisms of optic neuropathies and development of neural regenerative therapeutics by integrating the mentor team of Dr. Zhigang He at Boston Children?s Hospital and Harvard Medical School, Dr. Joshua Sanes at Harvard University and Harvard Brain Science Initiative, Dr. Jeffery Goldberg at Stanford University and Byers Eye Institute, and Dr. Jason Buenrostro at Harvard Stem Cell and Regenerative Biology (SCRB) Department and Broad Institute of MIT and Harvard. The candidate has also recruited Dr. Daniel Geschwind, a collaborator of his current and proposed studies, as his advisor for specific scientific and technical support. The proposed experiments and training activities will enable the candidate to publish top-tier ophthalmology research works and uniquely position him as an independent principal investigator pursuing novel therapeutics for retinal disease such as glaucoma. Glaucoma is the second leading cause of blindness in the United States with at least 3,000,000 people affected. This number is likely to increase by 60% by 2030 if no new therapeutics could be developped. Due to the inablity of central nervous system to regenerate after injury, the vision loss resulted from RGC death is irreversible and will lead to permanent blindness. Our preliminary experiments using the CRISPR/Cas9-based in vivo forward genetic screen have discovered that the knockdown of CCCTC-binding factor (CTCF) could robustly promote axonal regeneration of RGCs while do not increase overall RGC survival, and that the knockdown of structure specific recognition protein 1 (SSRP1) significantly protected RGC survival without facilitating axon regeneration. To explore the underlying epigenetic mechanisms regulating RGC survival and regeneration, the proposed study will specifically pursue the following aims: (1) To profile injury-induced chromatin remodeling in RGCs by ATAC sequencing (mentored phase); (2) To assess the mechanisms that mediate differential effects of CTCF and SSRP1 upon injury (mentored and independent phase); and (3) To assess the mechanisms and effects of epigenetic regulators in a glaucoma model (independent phase). The outcome of the proposed study will provide in-depth and quantitative insights into why and how the regenerative fates of RGCs are pre-determined from an epigenomic perspective, which can be directly transformed to new cures for optic neuropathies.
Due to the inablity of central nervous system to regenerate after injury, the vision loss in optic neuropathies such as glaucoma is irreversible and will eventually lead to permanent blindness. Based on the previous and preliminary data of an in vivo CRISPR forward genetic screen, this proposed study will address the scientific question why and how the regenerative fates of RGCs are pre-determined from an epigenomic perspective. By exploring the injured induced chromatin accessibility and gene expression profile changes in RGCs, the proposed study will ultimately provide novel drug targets for retinal regenerative medicine.