Epigenomic mechanisms regulating RGC survival and axon regeneration

Project Summary/Abstract 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 injury induced epigenetic regulators, such as CCCTC- binding factor (CTCF), can robustly promote RGC axonal regeneration or/and survival. 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 survival and regeneration regulators

upon injury (mentored and independent phase); and (3) To assess the mechanisms and effects of epigenetic regulators in a glaucoma model (independent phase). For the past two years during this K99 award, I have successfully accomplished all experiments and goals in Aim 1 and Aim2, with two manuscripts published on

Neuron in 2022 (and selected as cover story). For the extended period of my K award, I will further pursue the translational study of my approaches in glaucoma relevant mouse models. 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.