Glaucoma affects almost 80 million patients globally. In glaucoma, the optic nerve, which connects the eye to the brain, is progressively damaged, often in association with elevated pressure inside the eye.
What causes optic nerve degeneration in glaucoma is not entirely known, but there is currently a large focus on identifying new treatments that prevent nerve cells (called retinal ganglion cells) in the retina from dying, as well as trying to repair vision loss through the regeneration of diseased nerve fibres (axons) in the optic nerve.
In this study, scientists focused on a gene responsible for the production of a protein known as Protrudin which normally resides within the endoplasmic reticulum, tiny structures within our cells.
The team showed that the endoplasmic reticulum found in axons appears to provide materials and other cellular structures important for growth and survival in order to support the process of regeneration after injury. Protrudin stimulates transport of these materials to the site of injury.
In both cell models and animal models of optic nerve injury and glaucoma, gene therapy to provide more Protrudin stimulated the regeneration of nerve cells and protected them from degeneration.
“Gene therapy is a powerful strategy to deliver essential protective genes/proteins to the eye and is showing a lot of promise already for clinical use. To this, gene therapy has been used successfully in other eye diseases as well,” says Pete Williams, Assistant Professor and Research Group Leader for glaucoma at Karolinska Institutet and St. Erik Eye Hospital, one of the authors of this study.
Gene therapy for glaucoma is one of the key areas of Pete Williams’ research program being performed at St. Erik Eye Hospital.
“We are living in a very exciting time for glaucoma research. There is a lot of promise for gene therapies to protect and/or regenerate the optic nerve in diseases like glaucoma, but we need to continue to further research to develop safe and effective therapies for humans,” says Pete Williams.
The research was supported by the UK Medical Research Council, Fight for Sight, the Bill and Melinda Gates Foundation, Cambridge Eye Trust, the National Eye Research Council, the Swedish Research Council, Karolinska Institutet and St. Erik Eye Hospital philanthropic donations.
Protrudin functions from the endoplasmic reticulum to support axon regeneration in the adult CNS, Veselina Petrova, Craig S. Pearson, Jared Ching, James R. Tribble, Andrea G. Solano, Yunfei Yang, Fiona M. Love, Robert J. Watt, Andrew Osborne, Evan Reid, Pete A. Williams, Keith R. Martin, Herbert M. Geller, Richard Eva and James W. Fawcett, Nature Communications, online 5 Nov 2020, doi: 10.1038/s41467-020-19436-y