Washington (ISJ) ? Scientists at the Washington University School of Medicine in St. Louis have developed a technique to convert human skin cells directly to brain cells, affected by Huntington’s disease, a fatal neurodegenerative disorder. Tests on mouse by researchers demonstrated, the converted cells survived at least six months after injection into the brain and behaved similarly like brain cells. The new process of turning one cell into another, does not pass through a stem cell phase, avoiding the production of multiple cell types.
“Not only did these transplanted cells survive in the mouse brain, they showed functional properties similar to those of native cells,” said senior author Andrew S. Yoo, assistant professor of developmental biology. “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 produced a specific type of brain cell called medium spiny neurons, which are important for controlling movement. They are the primary cells affected in Huntington?s disease, an inherited genetic disorder that causes involuntary muscle movements and cognitive decline usually beginning in middle-adulthood. Patients with the condition live about 20 years following the onset of symptoms, which steadily worsen over a period of time.
The research involved adult human skin cells, rather than more commonly studied mouse cells or even human cells at an earlier stage of development. Yoo and his colleagues put the skin cells in an environment that closely mimics the environment of brain cells.
The researchers performed extensive tests to demonstrate that these newly converted brain cells did indeed look and behave like native medium spiny neurons. The converted cells expressed genes specific to native human medium spiny neurons and did not express genes for other types of neurons. When transplanted into the mouse brain, the converted cells showed morphological and functional properties similar to native neurons.
The findings were published in the latest issue of the journal Neuron.
The investigators are now taking skin cells from patients with Huntington’s disease and reprogramming them into medium spiny neurons. They also plan to inject healthy reprogrammed human cells into mice with a model of Huntington?s disease to see if this has any effect on the symptoms.
