Researchers have used gene therapy to regenerate damaged optic nerve fibres in a discovery that could lead to new glaucoma treatments in the future.
Professor Keith Martin, from the Centre for Eye Research Australia and University of Melbourne, was one of the leaders of the pre-clinical study published in Nature Communications.
He says the findings bring hope of future treatments which could repair the nerve damage which causes blindness in glaucoma and potentially even restore sight.
“We are excited about the potential to develop new treatments which could help glaucoma patients who do not respond to conventional treatments and continue to lose their vision despite low eye pressure.’’
About the research
Professor Martin and research colleagues from the University of Cambridge tested whether a gene responsible for producing a protein known as protrudin could stimulate the regeneration of nerve cells and stop them from dying when they were injured.
They used a cell culture system to grow brain cells in the lab and then injured them using a laser before introducing a gene to increase the amount of protrudin in the cells, vastly increasing their ability to repair and regenerate.
Tests of eye and optic nerve cells found the protein enabled significant regeneration weeks after a crush injury to the optic nerve.
The research demonstrated almost complete protection of nerve cells from a mouse retina growing in cell culture, a technique which would usually be expected to result in extensive cell death.
Professor Martin says the results are promising. “What we’ve seen is the strongest regeneration of any technique we’ve used before,’’ he says.
How does gene therapy work?
Gene therapy aims to treat blindness or vision loss caused by defective or missing genes.
Researchers usually identify the gene that is causing vision loss and then create a correct copy in the lab. The correct copy of the gene is then merged with a modified safe virus known as a viral vector and injected into the target cells.
In addition to repairing damaged cells, gene therapy can also be used to deliver genes to make cells stronger and more resistant to injury.
Emerging field
Professor Martin’s latest findings on glaucoma are part of a rapidly evolving field of ocular gene therapy, which is seeing new treatments developed in Australia and internationally.
In addition to his current research, Professor Martin has previously been involved in the development of a gene therapy for glaucoma which is moving towards human clinical trials.
Around the world, many new gene therapy treatments for eye disease are reaching clinical trial stage or being introduced to clinical practice.
The recent approval of the gene therapy Luxturna by Australia’s Therapeutics Goods Administration to treat a rare form of retinitis pigmentosa is just one example of treatments that are on the horizon for Australians.
Continuing research
Following their promising results, Professor Martin and his international team are continuing their pre-clinical glaucoma gene therapy research in Melbourne and Cambridge.
He says next steps are to conduct more investigations to explore the ability of protrudin to protect and regenerate human retinal cells in the lab.
This would help determine if they could be developed into an effective treatment for humans and in the longer term taken to clinical trial.
“In the past it seemed impossible we would be able to regenerate the optic nerve but our research shows the potential of gene therapy to do this,’’ says Professor Martin.
More information
Read the full study
Petrova, V et al. Protrudin functions from the endoplasmic reticulum to support axon regeneration in the adult CNS. Nat Comms; 5 Nov 2020; DOI: 10.1038/s41467-020-19436-y
Funding
The research was supported in the UK by The Medical Research Council, Fight for Sight, The Bill and Melinda Gates Foundation, Cambridge Eye Trust and the National Eye Research Council.
