Potent protein regenerates damaged optic nerve

A potent molecule that causes more regeneration of eye nerves than any other known has been found by researchers. The damaged eye nerves of rats that received injections of the protein showed five times better recovery than those that did not.

Drugs developed from the newly isolated protein – called oncomodulin – might one day even help heal spinal cord injury in humans. But experts stress that they have not yet tested to see if spinal cells respond to the molecule.

Several years ago, Larry Benowitz of the Children’s Hospital Boston, Massachusetts, US, and his colleagues demonstrated that the inflammatory response triggered by eye injury somehow promoted nerve regeneration in that organ. The body usually shuts down nerve regeneration after injury, probably to prevent erroneous re-connections being made, but the eye seems to be an exception in this instance. Nonetheless, isolating the molecule that promoted this healing remained a tough task, reports New Scientist.

According to Forbes, the finding could lead to new ways to treat blindness caused by optic nerve damage and even injuries of the spinal cord and brain.

Oncomodulin stimulates growth of injured nerve fibers (axons) in the central nervous system, which consists of the brain, spinal cord and eyes. Under normal circumstances, most axons in the central nervous system cannot regrow once they've been damaged.

But researchers at Children's Hospital Boston said that they had added oncomodulin to retinal nerve cells in a Petri dish and found that axon growth nearly doubled. The team then tested the growth factor in rats with optic nerve injury. They found a 5- to 7-fold increase in axon growth when oncomodulin was given along with a drug that helps cells respond to the growth factor.

The scientists also showed that oncomodulin switches on a number of genes associated with axon growth. The Boston team now plans to test whether the growth factor also works on the types of brain cells that would be potential targets in treating stroke and spinal cord injury.

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