Scientists Uncover New Clues to Repairing an Injured Spinal Cord

Although many animals have the ability to regrow nerves after an injury, humans and primates do not. However, new research from the Salk Institute suggests that a small molecule may be able to convince damaged nerves to grow and effectively rewire circuits which could eventually lead to therapies for thousands with severe spinal cord injuries or paralysis. During the study, researchers found that the protein p45 promotes nerve regeneration by preventing the axon sheath (known as myelin) from inhibiting growth. However, humans, primates, and some other more advanced vertebrates don’t have the p45 protein. Instead, the researchers discovered a different protein — p75 — that binds to the axon’s myelin when nerve damage occurs in these animals and then halts growth in damaged nerves. In the study, researchers analyzed how two p75 proteins bind together and form a pair that latches onto the inhibitors released from damaged myelin. By studying the configurations of the proteins in solutions using nuclear magnetic resonance (NMR) technology, the researchers found that the growth-promoting p45 could disrupt the p75 pairing. The findings suggest that an agent — either p45 or another disrupting molecule — that can effectively break the p75 pair could offer a possible therapy for spinal cord damage. Researchers say the next step will be to see if introducing the p45 protein helps regenerate damaged human nerves. To read more about this study, click here.