New Genes to Prevent Cell Death in Glaucoma

The goal of our project is to test the neuroprotective activity of four newly identified genes in zebrafish and mammalian models of glaucoma. We will perform loss-of-function experiments in the zebrafish optic nerve crush, and bug-eye elevated intraocular pressure injury models to test if four novel zebrafish genes are neuroprotective. We expect the loss of any one of the genes will impair survival and regeneration after injury. We will then perform gain-of-function, overexpression experiments in a mammalian cell culture to test for neuroprotective effects and generate the Adeno Associated Virus (AAV) particles necessary to test each gene’s function in vivo.

Loss of vision in glaucoma is caused by injury and death of the cells that connect the eye to the brain. Current treatments can delay the progression of cell death and vision loss, but no treatment exists to rescue injured cells and regenerate lost connections. Mammalian models of glaucoma also demonstrate this susceptibility to cellular injury and death without successful regeneration. In contrast, the zebrafish model exhibits resilience to injury and successful regeneration of lost connections to recover vision. Our laboratory is comparing the molecular and genetic response of zebrafish to mammals under conditions that model glaucoma. We have identified zebrafish-specific genes and responses that might mediate this difference. The current project uses loss of function studies in zebrafish and gain of function studies in mammalian cells to test the neuroprotective ability of four candidate genes identified in zebrafish. We will also generate the tools to test the function of these genes in mammalian models of optic nerve injury and glaucoma in vivo. The goal of this study is to understand the basic biology of injury resilience and optic nerve regeneration in the zebrafish and apply that knowledge to mammalian models of glaucoma with the long-term hopes of identifying new avenues for therapeutic development in patients.

Glaucoma patients and mammalian models of glaucoma-like conditions suffer vision loss due to death of retinal ganglion cells. Under similar conditions, zebrafish retinal ganglion cells survive and regenerate damaged axons. We will use CRISPR-Cas9 gene deletion in zebrafish and gene overexpression in mammalian cells to test four novel zebrafish genes for neuroprotective activity.

This basic biology research will increase our knowledge about the conditions necessary for retinal ganglion cell survival and axon regeneration under injury conditions like those seen in glaucoma. We will generate new zebrafish gene mutants and mammalian AAV vectors that will provide a resource for future study of these genes and neuroprotective pathways. We hope that the genes and pathways identified in this project will stimulate new directions in glaucoma research and one day result in new treatments to preserve or regain lost vision.