Researchers at Harvard Medical School and Children’s Hospital Boston have isolated a molecule that stimulates the regrowth of damaged adult nerve fibers, providing new hope for those suffering from nerve damage and from neurodegenerative diseases.
Adult nerve fibers in the brain, spinal cord, and optic nerve – all parts of the central nervous system – are notoriously difficult to repair once damaged. In extreme cases, such as spinal cord injury, such damage can be responsible for devastating paralysis.
Led by Associate Professor of Neurosurgery Larry Benowitz, researchers identified a mysterious protein whose effects were first noticed seven years ago when injured optic nerves spontaneously began to regenerate in some of their experimental animals.
One of several surprises in this work, Benowitz said, is that the protein, oncomodulin, does not belong to any known family of growth factors, but to an entirely different family of proteins.
It took time not only to identify oncomodulin, but also to figure out the right conditions for the molecule to be effective. Oncomodulin works best in the presence of two other molecules, and even better when substances known to inhibit adult nerve growth are neutralized. So far, oncomodulin has been proven to work on retinal ganglion cells – which connect the eye to the parts of the brain responsible for processing visual signals – and at least one other type of nerve cell.
The research, reported in the May 14 online edition of the journal Nature Neuroscience and scheduled for release in print in June, was led by Benowitz. The first author is Instructor in Neurosurgery Yuqin Yin, who conducted most of the studies reported in the article. Other Harvard investigators include Research Fellow in Surgery Barbara Lorber and Research Fellow in Ophthalmology Toru Nakazawa. Other participants include colleagues at Children’s Hospital, the Massachusetts Institute of Technology, and the University of Missouri.