The neurons (red) that the researchers derived from embryonic fibroblasts.
Credit: Thomas Vierbuchen/Marius Wernig
BRISBANE: Researchers have transformed adult mouse skin cells directly into functional nerve cells, skipping the stem cell stage, in a huge step towards treating diseases such as Alzheimer's or spinal cord injuries.
"We actively and directly induced one cell type to become a completely different cell type," said pathologist Marius Wernig, from the Stanford University School of Medicine in California.
"These are fully functional neurons. They can do all the principal things that neurons in the brain do."
The technique could eventually be used to treat any condition where neurons need to be replaced, such as Alzheimer's or Parkinson's disease, or spinal cord injuries, said the study's lead author Thomas Vierbuchen, a stem cell researcher at Stanford University in Palo Alto, California.
Study nervous system diseases
The cells could also be used to study nervous system diseases caused by DNA mutations or to test new drugs, according to the study published today in the British journal Nature.
This is the first time scientists have turned one type of mature cell into another. Once a cell has differentiated - that is, it's turned from an immature cell into a brain cell or a skin cell or a liver cell - it stays as that type of cell until it dies.
But immature cells, or stem cells, have the ability to differentiate into any type of cell. Until now, scientists have been transforming cells back into the stem cell stage, which they call pluripotency.
Skipping the stem cell stage
This new process skips this stage, and in doing so it bypasses the ethical issues involved in using embryonic or embryo-like stem cells to produce patient-specific cells for regenerative medicine.
It also solves some of the practical problems involved in using cells produced via pluripotency, said the report's lead author Thomas Vierbuchen.
The scientists used a cell type called a fibroblast, found in the connective tissue and easily collected from skin biopsies, because they knew that mature, differentiated cells such fibroblasts could be made pluripotent by activating particular genes. The particular genes code for four transcription factors, compounds that control which genes are turned on or off in the cell.
Those pluripotent cells can then be coaxed to become other kinds of cells, such as neurons, that are genetically identical to the donor patient. This means they won't be rejected by the body's immune system if used to replace cells, but they can also produce tumors if a few pluripotent cells are implanted along with the new cell type, Vierbuchen said.
Brain Cells created directly from skin cells
Great discovery, but as usual, it will take another 20 years or more before it can help a person !! We, who are affected by any of these diseases or injuries, are sick of hearing about the next discovery because nothing is ever done clinically to help anyone who is suffering - so why bother ?
Brain Cells from skin cells
Wow..you sound like a pretty negative individual..."why bother". Suggestion...stop breathing...why bother? By "bothering", we will get the answers and the cures. Someone as negative as you, will never be happy, even if scientists give you the power of willed flight.
Brain cells from fibroblasts
What a wonderful result.Are fibroblasts special in having the potential to reprogramme to the pluripotent stage or to other tissues as well?
A new door is open, exploring this field will be great.