MicroRNAs in Early Retinal Development and Their Application in Retinal Organoids to Treat Retinal Ganglion Cell Degenerative Conditions

The retina is the light sensitive tissue at the back of the eye that processes the essential first steps of vision and contains several populations of neurons. Retinal Ganglion Cell (RGC) axons form the optic nerve, which is the only connection between the retina and the brain. Glaucoma is a leading cause of irreversible vision loss, affecting millions of people annually, and advanced stage glaucoma patients are blinded as a result of RGC degeneration. Since the human central nervous system possesses no functional regenerative capacity, there is ample interest in developing cell replacement therapies for optic neuropathies like glaucoma. In this dissertation, I describe work that I accomplished with my colleagues, both unpublished and published, that is relevant to human medicine and basic science alike. In my unpublished work, I generated a novel induced Pluripotent Stem Cell line that labels RGCs with a green fluorescent protein and attempted to engineer these cells with an inducible transgenic platform to expand the production of RGCs, but discovered potent transgenic silencing. My published work covers a range of topics; with colleagues, I developed a novel red fluorescent protein RGC reporter mouse that labels 70% of RGCs in the mouse retina from the earliest points of RGC development through adulthood. Additionally, this reporter can be visualized live and, since it uses a red fluorescent protein, can easily be combined with any green fluorescent protein reporter without crossing fluorescent signals. I have also shown that an endogenous glial cell of the retina, Müller glia, secrete factors that promote stem cell-derived RGC survival in vitro, which may help identify methods to promote transplanted cell survival in future therapies. I analyze the landscape of microRNA (miRNA) expression in the developing non-human primate fovea with the La Torre lab to study how the fovea, which is a region of the retina essential for acute human vision, develops. Finally, with my mentor Dr. Anna La Torre, I review the state of the RGC transplantation field to identify areas that require technical achievement to grow closer to establishing a reliable method of RGC transplantation in vivo