In what may be the most exciting news this week, researchers have engineered a novel drug cocktail that fixes damaged neurons turning them into functional ones. The team of scientists from Penn State found a set of four molecules that could transform glial cells into new healthy neurons.
Glial cells, also called neuroglia, are non-neuronal cells in the central nervous system that maintain homeostasis and provide protection for neurons. As such, they are ideal targets for new healthy neurons.
Brain repair is complicated
"The biggest problem for brain repair is that neurons don't regenerate after brain damage, because they don't divide," said Gong Chen, professor of biology and Verne M. Willaman Chair in Life Sciences at Penn State and leader of the research team.
"In contrast, glial cells, which gather around damaged brain tissue, can proliferate after brain injury. I believe turning glial cells that are the neighbors of dead neurons into new neurons is the best way to restore lost neuronal functions."
This isn't the first time Chen's team attempted this converting process. They previously tried other sequences featuring nine small molecules that could reprogram human glial cells into neurons.
But a large number of molecules made it difficult to use in clinical treatment. Luckily, they eventually found an approach that worked.
"We identified the most efficient chemical formula among the hundreds of drug combinations that we tested," said Jiu-Chao Yin, a graduate student in biology at Pen State who identified the ideal combination of small molecules.
"By using four molecules that modulate four critical signaling pathways in human astrocytes, we can efficiently turn human astrocytes--as many as 70 percent--into functional neurons."
The team also attempted an approach with three small molecules but saw their conversion rate drop by about 20 percent. In addition, using just a single molecule, saw no conversion whatsoever.
Four was indeed the right number, and the reprogramming it generates is nothing short of impressive. The resulting neurons can survive more than seven months in a culture dish and even form functioning neural networks such as those normal brain neurons make.
Chen argues that the most significant advantage of his approach is that it could be delivered via a simple pill.
"The most significant advantage of the new approach is that a pill containing small molecules could be distributed widely in the world, even reaching rural areas without advanced hospital systems," said Chen.
"My ultimate dream is to develop a simple drug delivery system, like a pill, that can help stroke and Alzheimer's patients around the world to regenerate new neurons and restore their lost learning and memory capabilities."
The researchers, however, note that much work needs to be done before drugs using small molecules could be developed. In addition, any potential side effects also need to be studied and identified.
Still, the team has great hope for the potential of their cocktail to one day treat neurological disorders.
"Our years of effort in discovering this simplified drug formula takes us one step closer to reaching our dream," said Chen.
The study is published in the journal Stem Cell Reports.