Spinal cord regeneration possible in animals

Scientists have been able to activate specialised proteins involved in the regenerative gene production to help regrow sensory and motor neurons in animal spinal cords after severe injury.

In results published in PLOS Biology, researchers showed  that a treatment using a chemical activator called TTK21 can stimulate the regrowth of motor and sensory axons after a spinal cord injury, as well as “synaptic plasticity” which is the development of synapses that connect brain cells to each other to allow communication between them.

“This work shows that a drug called TTK21 that is administered systemically once per week after a chronic spinal cord injury in animals can promote neuronal regrowth and an increase in synapses that are needed for neuronal transmission,” said senior author Professor Simone Di Giovanni from University College London.

“This is important because chronic spinal cord injury is a condition without a cure where neuronal regrowth and repair fail.”

Severe spinal cord injuries can be caused by a range of factors or events and are characterised by the absence of axon regrowth, connectivity and severe neurological disability. Axons are the cable-like structures through which electrical impulses are sent from one neuron to another.

The TTK21 treatment was given to adult mice three months after receiving a spinal cord injury that destroyed sensory fibres and motor tracts, reducing mobility and emulating severe spinal cord injury.

This molecule has been shown in previous experiments to activate specialised proteins involved in the production of genes that trigger neurone regeneration and enhance memory deficits.

After 10 weeks of treatment, the scientific team observed more axons ‘sprouted’ in the spinal cords of test mice, and that growth of sensory axons increased above the region where the injury occurred.

Their findings suggest the TTK21 molecule could be used in combination with other therapies to assist with spinal repair and axon growth. They described their findings as demonstrating a “clinically suitable molecular intervention (which) can promote plasticity and growth in both an acute … and chronic spinal cord injury.”

“We are now exploring the combination of this drug with strategies that bridge the spinal cord gap, such as biomaterials, as possible avenues to improve disability in SCI patients,” says Di Giovanni.