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Discovery from Universit茅 de Montreal and McGill University鈥檚 Montreal Neurological Institute

Montreal, February, 1, 2010 鈥� Scientists have identified a double agent in the eye that, once triggered, can morph from neuron protector to neuron killer. The discovery has significant health implications since the neurons killed through this process results in vision loss and blindness.

The findings, published in the journal Proceedings of the National Academy of Sciences (PNAS), are collaboration between the Universit茅 de Montreal, 香蕉视频 and the Montreal Neurological Institute in Canada and the Universit茅 de Namur in Belgium. The researchers show how an unusual molecule, called proNGF, activates glial cells that normally protect neurons in the retina and brain.

鈥淲e found that glial cells attack and kill neurons after being triggered by proNGF,鈥� says coauthor Dr. Philip Barker, a neuroscientist at the Montreal Neurological Institute and a professor at the McGill Department of Neurology and Neurosurgery. 鈥淪ince glial cells normally protect neurons, we were surprised to find that proNGF can convert glial cells into killers that cause neuron death in the retina.鈥�

Coauthor Dr. Adriana Di Polo, a professor at the Universit茅 de Montr茅al Department of Pathology and Cell Biology, compares the proNGF molecule to a cell hijacker. 鈥淏efore this study, we didn鈥檛 know what physiological role the proNGF molecule played in the eye,鈥� she says. 鈥淲e now propose that, following brain damage or neurodegenerative diseases, proNGF alters the glial cell network to change its function. Rather than protecting neurons, proNGF makes the glial cells attack neurons."

Scientists must now pay more attention to the damage proNGF can trigger. 鈥淥nce retinal neurons die, they are gone forever and the permanent loss of these cells causes blindness,鈥� warns Dr. Di Polo. 鈥淭he next step for researchers is to explore whether proNGF signals can be controlled", says Fr茅d茅ric Lebrun-Julien, first author and a PhD student at the Universit茅 de Montr茅al's Department of Pathology and Cell Biology.

Dr. Barker concurs. 鈥淚f we can block factors induced by proNGF, we can protect neurons that would normally be lost. We think these findings may eventually translate into clinical benefits in diseases such as glaucoma.鈥�

Partners in research:
The study was supported by the Canadian Institutes of Health Research and the Fonds de Recherche en Sant茅 du Qu茅bec.

About the study:
The paper, 鈥淧roNGF induces TNF伪-dependent death of retinal ganglion cells through a p75NTR non-cell-autonomous signaling pathway,鈥� published in the journal PNAS, was authored by Fr茅d茅ric Lebrun-Julien and Adriana Di Polo of the Universit茅 de Montr茅al; Olivier De Backer of the Universit茅 de Namur in Belgium; David Stellwagen, Mathieu J. Bertrand, Carlos R. Morales and Philip A. Barker of the Montreal Neurological Institute / McGill University.

On the Web:

• About the Universit茅 de Montr茅al:
• About the Montreal Neurological Institute:
• About PNAS:

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