I am a bit behind in my reading, so just today I saw an incredible article in the February 27th issue of Science News. The article, entitled “From Skin Cells to neurons, with no middle man,” discussed some astonishing experiments in which mouse skin cells were turned directly into neurons.1
Researchers at Stanford University took skin fibroblast cells (cells that make a protein called collagen) from a mouse and used a virus to insert genes that encode certain transcription factors. These transcription factors are proteins that actually help to regulate gene activity. In other words, their job is to turn genes on and off. The idea here is that even though skin cells are specialized, they have the same DNA that any other non-reproductive cells have. Thus, if we could “turn on” the right genes and “turn off” other genes, we could turn one type of cell into another type of cell.
So…the researchers inserted genes for three transcription factors that are present when neurons are just starting to form. It is assumed that these transcription factors activate the genes necessary for a stem cell to become a neuron, and they deactivate the genes that a neuron doesn’t need. The researchers thought that if they forced those transcription factors to appear in a skin cell, the transcription factors would turn on and off the right genes to make the skin cell turn into a neuron. They were right.