Functional nerve cells grown from skin

In a breakthrough, scientists have generated mature nerve cells from skin cells, an advance that could enhance the understanding of neurodegenerative diseases and accelerate the development of new drugs.
The nerve cells generated by a new method show the same functional characteristics as the mature cells found in the body, making them much better models for the study of age-related diseases such as Parkinson's and Alzheimer's, and for the testing of new drugs, researchers said.
Eventually, the technique could also be used to generate mature nerve cells for transplantation into patients with a range of neurodegenerative diseases, they said.
By studying how nerves form in developing tadpoles, researchers from the University of Cambridge were able to identify ways to speed up the cellular processes by which human nerve cells mature.

Stem cells are our master cells, which can develop into almost any cell type within the body. Within a stem cell, there are mechanisms that tell it when to divide, and when to stop dividing and transform into another cell type, a process known as cell differentiation.
Several years ago, researchers determined that a group of proteins known as transcription factors, which are found in many tissues throughout the body, regulate both mechanisms.

More recently, it was found that by adding these proteins to skin cells, they can be reprogrammed to form other cell types, including nerve cells.
By manipulating the signals which transcription factors send to the cells, Dr Anna Philpott and her collaborators were able to promote cell differentiation and maturation, even in the presence of conflicting signals that were directing the cell to continue dividing.

When cells are dividing, transcription factors are modified by the addition of phosphate molecules, a process known as phosphorylation.
By engineering proteins which cannot be modified by phosphate and adding them to human cells, the researchers found they could produce nerve cells that were significantly more mature, and therefore more useful as models for disease such as Alzheimer's.
The findings appear in the journal Development.