Although most of the body’s tissues can regenerate after injury, some of the most important tissues cannot. This includes axons, a long nerve fiber that transmits signals between neurons. But now, researchers at Tempo University have found that enhancing a protein helps repair axons that allow mice with spinal cord injuries to regain more movement and sensation.
The axon acts like a cable, swaying through the body. They are an important channel through which the brain gives instructions to the muscles, as well as an important channel for tissues to report pain and other touch. Although they are important, axons do not recover from injury, which is why spinal injuries can be so debilitating.
Now, tempo University’s medical team may have identified a potential new treatment target. The key is a protein called Lin28, which is expressed in large numbers in embryonic stem cells, and researchers in past studies have found that raising Lin28 levels can help mice regenerate skin, bones, cartilage and other tissues. In the new study, researchers tested whether it could also help repair damaged axons.
First, the team engineered mice in some tissues that overexpressed Lin28. When the mice were fully older, they were then injured in their spinal cord or optic nerve (the optic nerve that connects the eyes and brain) in the control group. After giving the same damage to another group of subjects, the molecule was injected with mice with normal Lin28 secretion.
Overall, the researchers found, the extra Lin28 contributes to the regeneration of axons, which spread to 3 millimeters outside the damaged area of the spinal cord and along the entire optic nerve channel. Interestingly, injections appear to be the most effective method of restoring more coordination and perception in mice with spinal cord injuries.
The results suggest that Lin28 is the main regulator for axon regeneration and a promising therapeutic target for central nervous system damage, senior researchers in the study said. They have observed a large number of axon regeneration, which may be clinically significant, as there is currently no regenerative treatment for spinal cord or optic nerve injury.
Next, the researchers hope to study how the Lin28 molecule can be passed on to human patients. Other related growth signal molecules can also be tied to Lin28 for better results, the team said.
The findings were published in the journal Molecular Therapy.