The managing director of one of Australia’s pre-eminent eye research institutions is a leading scientist behind experiments on mice that have shown promise for developing new gene therapies for both glaucoma and dementia.
Professor Keith Martin from the Centre for Eye Research Australia and University of Melbourne, and Dr Tasneem Khatib from the University of Cambridge, have led a pre-clinical study using a new combined gene therapy technique to repair damage to nerve cell transport systems that cause vision loss in glaucoma and memory loss in dementia.
More critically, their findings, published in Science Advances, demonstrate how gene therapies could treat complex neurodegenerative diseases that are caused by multiple factors rather than a single genetic fault.
“More common neurodegenerative diseases like glaucoma or dementia are much more complex and caused by a range of genetic and other contributing factors,” he said.
“Although the research is in early stages, it shows promise for developing gene therapies for many of these common diseases to complement existing therapies.”
In pre-clinical experiments, the researchers tested a new gene therapy to determine if it could stimulate axon growth and improve optic nerve function.
They combined two key molecules into a single viral vector and delivered it to mice affected by glaucoma and dementia.
Prior to therapy, both groups had impaired optic nerve function with reduced transmission of electrical signals between the eye and brain. Those with glaucoma also showed signs of reduced vision.
However, after the therapy was delivered, optic nerve activity improved in both groups and the mice with glaucoma showed signs of improved vision.
There was also a possible small improvement in the mice’s short-term memory, which researchers now plan to test in a larger study to confirm the effect.
The study also took a new approach to delivering gene therapy by combining two molecules thought to improve axon function – brain derived neurotrophic factor (BDNF) and tropomyosin receptor kinase B (TrkB) – in one treatment.
Typically, most gene therapies deliver only one molecule or gene in a treatment.
“Rather than using the standard gene therapy approach of replacing or repairing damaged genes, we used the technique to supplement molecules in the brain,’’ Khatib said.
He noted that the combined approach led to a more sustained therapeutic effect.
“We reckoned that replacing two molecules that we know work effectively together would help to repair this transport network more effectively than delivering either one alone, and that is exactly what we found.”