Mechanism found to boost axon regeneration in the nervous system
Damage to the central nervous system, such as spinal cord injuries, may cause permanent loss of sensory and motor function. This is because the severed axons are unable to regenerate. Patients who suffer such injuries currently have limited options to regain their motor abilities. Scientists have been exploring ways to enable the regeneration of severed axons, with a view to developing viable treatments in the future.
At the Hong Kong University of Science and Technology, a team led by Professor Kai Liu studied the regeneration of severed axons and untangled some of its complexities. They found that the deletion of a phosphatase-coding gene, named PTPN2, can prompt axons to regrow.
The human nervous system is composed of two parts: the central and the peripheral. Compared with the former, peripheral nerves have stronger ability to regrow and repair after injury. Scientists have yet to fully understand the relationship between this self-repair and the intrinsic immune mechanism of the nervous system. Two mysteries the team wanted to resolve were how immune-related signalling pathways affected neurons after injury, and whether they could enhance axonal regeneration directly.
This study investigated what is known as the ‘IFNγ-cGAS-STING’, a mediator of inflammation in the settings of cellular stress and tissue damage. Researchers wanted to know whether this signalling pathway had any role in the regeneration process of peripheral nerves. Researchers discovered that peripheral axons could directly modulate the immune response in their injured environment to promote self-repair after injury.
In previous research, Liu’s team had already demonstrated that elevating the neuronal activity and regulating the neuronal glycerolipid metabolism pathway could boost axon regenerative capacity. The current study provides further insights to the search of treatment solutions for challenging conditions such as spinal cord injuries, with one possible option being the joining of several types of signalling pathways.
Their results were recently published in the scientific journal Neuron.