Scientists have successfully transformed skin cells into functional nerve cells, completely skipping an interim to-be-determined stage previously thought to be required.
A Stanford-based team used lentiviruses to apply three genes to embryonic skin cells, converting them into nerve cells in a laboratory dish after just five days and with nearly 20 percent efficiency.
“We actively and directly induced one cell type to become a completely different cell type,” said study author Marius Wernig, whose work was published yesterday by Nature (press release). “These are fully functional neurons. They can do all the principal things that neurons in the brain do.”
The pluripotent cellular stage bypassed here is when the fate of undifferentiated cells can be decided. A couple of years ago, induced pluripotent stem (iPS) cells were created by applying transcription factors to human skin cells. Once they reached the pluripotent stage, the cells could be coaxed to become a new cell type, in a remarkable demonstration of cellular plasticity.
Rather than having to go backward to go forward, Wernig wondered if this pluripotent pit stop was really necessary (The Scientist). “It’s almost scary to see how flexible these cell fates are,” he said after finding it wasn’t (MIT Technology Review).
This new method offers the possibility of skipping several steps, including using human embryos (Reuters). Researchers can now attempt to duplicate the experiment with human cells, which would have huge effects on studies of Parkinson’s, Alzheimer’s, and other brain diseases by allowing neurological disease modelling and the study of regenerative medicine in vitro.
Image: neurons growing on mouse embryonic fibroblast cells / Thomas Vierbuchen/Marius Wernig