Scientists have developed a method of converting human skin cells into the type of brain cells that are affected by Huntington’s disease, prompting hopes that the technique could one day be used to provide a treatment for the devastating condition.

The approach, which unlike other regenerative research does not involve the production of stem cells, has been successfully demonstrated in mice, and is now being trialled in humans with the disease.

“Not only did these transplanted cells survive in the mouse brain, they showed functional properties similar to those of native cells,” said study senior author Dr Andrew S Yoo, assistant professor of developmental biology at Washington University School of Medicine in St Louis.

Huntington’s disease is a neurodegenerative disorder that causes movement-controlling brain cells know as medium spiny neurons to deteriorate, resulting in a slow loss of control over movement, the onset of dementia and eventual death. There is no cure at present.

Although a hereditary disease, the symptoms of Huntington’s can begin at any age, but most typically occur in the late 30s or early 40s. Between five and ten people per 100,000 will be afflicted by Huntington’s, depending on ethnicity and location.

This new technique would in theory allow degenerated brain cells to be replaced with newly reprogrammed ones, potentially reversing the decline in motor control that Huntington’s sufferers experience.

The treatment could also involve converting the patient’s own skill cells, which would dramatically reduce the chance of the body rejecting the new brain cells.

Skin cells already contain the DNA instructions to become other types of cells, so for the scientists the focus was on developing a system to encourage this to happen.

They already knew that exposing skin cells to microRNAs – small molecules of ribonucleic acid, a close cousin of our own DNA – would cause them to change into other cell types, so the primary work was fine-tuning the process to produce the specific type of brain cells needed.

“We think that the microRNAs are really doing the heavy lifting,” said study co-first author Matheus Victor, a graduate student in neuroscience.

“They are priming the skin cells to become neurons. The transcription factors we add then guide the skin cells to become a specific subtype, in this case medium spiny neurons.”

This reprogramming technique not only offers hope for Huntington’s, but could also be applied to other types of cells, giving it promise for a wide range of genetic conditions.

“We think we could produce different types of neurons by switching out different transcription factors,” added Victor.

The research was published today in the neuroscience journal Neuron.

Featured image courtesy of Jensflorian. Inline image courtesy of Leevanjackson.