Glial cells, which normally protect neurons in the retina can also kill them, resulting in vision loss and blindness has been discovered by scientists from University of Montreal and McGill University's Montreal Neurological Institute.
They found that a molecule, called proNGF, activates glial cells that kill neurons.
"We found that glial cells attack and kill neurons after being triggered by proNGF," said coauthor Dr. Philip Barker, a neuroscientist at the Montreal Neurological Institute and a professor at the McGill Department of Neurology and Neurosurgery. "Since 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."
The researchers compared the proNGF molecule to a cell hijacker.
"Before this study, we didn't know what physiological role the proNGF molecule played in the eye," said coauthor Dr. Adriana Di Polo, a professor at the Universite de Montreal Department of Pathology and Cell Biology.
"We 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," she added.
Scientists must now pay more attention to the damage proNGF can trigger.
"Once retinal neurons die, they are gone forever and the permanent loss of these cells causes blindness," said Di Polo.
"The next step for researchers is to explore whether proNGF signals can be controlled", said Frederic Lebrun-Julien, first author and a PhD student at the Universite de Montreal's Department of Pathology and Cell Biology.
Dr. Barker concurs. "If 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."
The findings are published in the journal Proceedings of the National Academy of Sciences (PNAS).