Neurobiologist Marie T. Filbin, a Distinguished Professor in the Department of Biological Sciences of Hunter College of the City University of New York (CUNY), has made a research breakthrough that has important long-term therapeutic potential for victims of spinal cord injuries.
Filbin has found a way to block the inhibiting function of the molecule MAG (myelin-associated glycoprotein) and all other inhibitors present in the myelin sheath that prevent the spinal cord from regenerating after injury. Her findings are reported in the January issue of Neuron magazine, published on January 28.
Up to now, researchers have been focusing on how to block individual inhibitors that prevent axons, the long part of the nerve, to regrow after injury. Filbin's is the first known discovery of a mechanism that can generally overcome all the inhibitors in myelin at once.
"We've shown that if you prime a neuron by treating it with certain growth factors called neurotrophins before exposing the neuron to MAG or myelin, you completely reverse the inhibition of axonal regrowth," explains Filbin. "The neurotrophins are affecting a molecule inside the neuron called cyclicAMP, which causes a cascade of events that ultimately block the regrowth inhibition." However, Filbin has found that no blocking effect occurs if the neuron is exposed to neurotrophins and MAG or myelin at the same time. The neuron must be "primed" first.
Filbin co-authored the article, "Prior Exposure to Neurotrophins Blocks Inhibition of Axonal Regeneration by MAG and Myelin Via a cAMP-Dependent Mechanism," with four Ph.D. students in Biology: Dongming Cai, Yingjing Shen, MariaElena DeBellard and Song Tang. Although the doctorate is granted by the CUNY Graduate Center, the Biology program is based at Hunter College. "These students worked with me night and day," says Filbin with pride.