Novel Factor Spurs Nerve Regeneration

Dramatically increased growth of
axons into the optic nerve (bottom
panel); © Larry Benowitz

Neuroscientists Yuqin Yin, MD, PhD, and Larry Benowitz, PhD, at Children’s Hospital Boston did their studies in the optic nerve. When oncomodulin was added to retinal nerve cells in a Petri dish, with known growth-promoting factors already present, axon growth nearly doubled.

“To make this finding clinically useful, we wanted to understand what was triggering the growth, so we could achieve nerve regeneration without causing an injury,” Benowitz says. No other growth factor was as potent, according to their paper. In live rats with optic-nerve injury, oncomodulin released from tiny sustained-release capsules increased nerve regeneration 5- to 7-fold when given along with a drug that helps cells respond to oncomodulin. Yin, Benowitz and colleagues also showed that oncomodulin switches on a variety of genes associated with axon growth.

Benowitz, the study’s senior investigator, believes oncomodulin could someday prove useful in reversing optic-nerve damage caused by glaucoma, tumors or traumatic injury. In addition, the lab has shown that oncomodulin works on at least one other type of nerve cell, and now plans to test whether it also works on the types of brain cells that would be relevant to treating conditions like stroke and spinal cord injury.

Working in Benowitz’s lab, Yin took a closer look and found that the macrophages secreted an essential but as-yet unidentified protein. Further studies revealed it to be oncomodulin, a little-known molecule first observed in association with cancer cells. “Out of the blue, we found a molecule that causes more nerve regeneration than anything else ever studied,” Benowitz says. “We expect this to spur further research into what else oncomodulin is doing in the nervous system and elsewhere.”; Source: Children’s Hospital Boston