In what is being hailed as a breakthrough study, scientists have successfully achieved regeneration of nerve connections after a spinal cord injury.
UC Irvine, UC San Diego and Harvard University team conducted the study on rodents.
They did this by deleting an enzyme called PTEN (a phosphatase and tensin homolog). PTEN activity is low early during development, allowing cell proliferation.
It then turns on when growth is completed, inhibiting mTOR and precluding any ability to regenerate.
Even a small spinal cord injury can cause paralysis of arms and legs, loss of ability to feel below the shoulders, inability to control the bladder and bowel, loss of sexual function, and secondary health risks including susceptibility to urinary tract infections, pressure sores and blood clots due to an inability to move the legs.
Zhigang He a senior neurology researcher first showed in a 2008 study that blocking PTEN in mice enabled the regeneration of connections from the eye to the brain after optic nerve damage.
He then partnered with Oswald Steward and Binhai Zheng to see if the same approach could promote nerve regeneration in injured spinal cord sites.
"Paralysis and loss of function from spinal cord injury has been considered untreatable, but our discovery points the way toward a potential therapy to induce regeneration of nerve connections following spinal cord injury in people," said Steward.
Results of their study appear online in Nature Neuroscience.