Researchers use quality treatment to recover harmed optic nerve filaments

Overview

• Post By : Kumar Jeetendra


• Source: University of Cambridge


• Date: 05 Nov,2020

Scientists have used gene therapy to regenerate damaged nerve fibers from the eye, in a discovery that could aid the development of new treatments for glaucoma, one of the main causes of blindness worldwide.

Axons – nerve pathways – in the adult central nervous system (CNS) do not normally regenerate after injury and disease, meaning that damage is often irreversible. However, over recent years there have been numerous discoveries that suggest it could be possible to stimulate regeneration.

In a study published today in Nature Communications, scientists tested whether the gene responsible for the production of a protein called Protrudin could trigger the regeneration of nerve cells and protect them from cell death after an injury.

The group, led by Dr Richard Eva, Professor Keith Martin and Professor James Fawcett in the John van Geest Centre for Brain Repair at the University of Cambridge, used a cell culture system to grow brain cells in a dish. They then injured their axons using a laser and examined the response to this injury using live-cell microscopy. The researchers found that increasing the amount or activity of Protrudin in these nerve cells significantly increased their ability to regenerate.

Nerve cells in the retina, known as retinal ganglion cells, extend their axons from the eye to the brain through the optic nerve so as to relay and process visual information. To investigate whether Protrudin might stimulate repair in the injured CNS in an intact organism, the researchers used a gene therapy technique to increase the amount and activity of Protrudin in the eye and optic nerve. When they measured the amount of regeneration a few weeks following a crush injury to the optic nerve, the group found that Protrudin had enabled the axons to regenerate over large distances. They also found that the retinal ganglion cells were protected from cell death.

Our strategy relies on using gene therapy – an approach already in clinical use – to deliver Protrudin into the eye. It’s possible our treatment could be further developed as a way of protecting retinal neurons from death, as well as stimulating their axons to regrow. It’s important to point out that these findings would need further research to see if they could be developed into effective treatments for humans.”

Dr. Veselina Petrova, Department of Clinical Neurosciences, University of Cambridge, the study’s first author

The researchers showed that this technique may help protect against glaucoma, a common eye condition. In glaucoma, the optic nerve that connects the eye to the brain is progressively damaged, often in association with elevated pressure inside the eye. If not diagnosed early enough, glaucoma may result in loss of vision. In the united kingdom, round one in 50 people over the age of 40, and one in ten individuals over age 75 is affected by glaucoma.

To demonstrate this protective effect of Protrudin against glaucoma, the researchers used a whole retina by a mouse eye and grew it in a cell-culture dish.

Glaucoma is one of major causes of blindness worldwide. The causes of glaucoma are not completely understood, but there is presently a massive focus on identifying new therapies by preventing nerve cells in the retina from dying, as well as trying to fix vision loss through the regeneration of diseased axons through the optic nerve.

Protrudin normally resides inside the endoplasmic reticulum, miniature structures within our cells. In this study, 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 encourage the process of regeneration after injury. Protrudin stimulates transport of those materials to the site of injury.

Dr Petrova added:”Nerve cells in the central nervous system lose the capacity to regenerate their axons as they grow, so have very limited capacity for regeneration. This means that injuries to the brain, spinal cord and optic nerve have life-altering consequences.

“The optic nerve injury model is frequently used to explore new treatments for stimulating CNS axon regeneration, and treatments identified this way often show promise in the injured spinal cord. It’s possible that increased or triggered Protrudin might be used to boost regeneration in the injured spinal cord.”