Scientists were able to create functional brain cells from skin cells to fight off the fatal neurodegenerative disorder Huntington's disease. This breakthrough study was the first to use a technique that created cells that did not go through a stem cell phase, avoiding the production of different cell types.

A team of researchers at Washington University School of Medicine in St. Louis placed human skin cells in a controlled environment made for brain cells, and exposed the cells to two microRNAs that they knew would affect the DNA in the cells. The scientists then exposed the cells to transcription factors that made it possible for the human skin cells to convert into the specific neurons.

The scientists successfully converted the skin cells into medium spiny neurons, which are the brain cells that control movement and are the ones that are affected by Huntington's disease.

"We think that the microRNAs are really doing the heavy lifting," says study co-author and graduate student in neuroscience Matheus B. Victor. "They are priming the skin cells to become neurons."

The researchers then injected the neurons into the brains of mice with Huntington's.

"Not only did these transplanted cells survive in the mouse brain, they showed functional properties similar to those of native cells," says Andrew S. Yoo, PhD, assistant professor of developmental biology and lead study author. "These cells are known to extend projections into certain brain regions. And we found the human transplanted cells also connected to these distant targets in the mouse brain. That's a landmark point about this paper."

The researchers found that skin cells injected into the brains of mice with Huntington's disease were able to convert into functional brain cells that survived for at least six months.

Huntington's disease is an inherited neurodegenerative disease that causes a gradual decline in mental ability due to damaged brain cells. The fatal disease commonly develops when a person reaches middle age. Patients can live for 20 years after their symptoms begin.

Published in the Oct. 22 issue of the journal Neuron and funded by the National Institutes of Health, the study aims to uncover more information about the deadly disease. Using this method could allow patients to use their own skin cells to reduce the chance of immune rejections to the treatment.