A research group at the Stanford University School of Medicine found that skin cells from mice can be repurposed as cells that can later become any of the three germ layers of the nervous system. This finding contradicts the prevalent notion that a cell must be a pluripotent stem cell in order to develop into any of the three primary tissue layers.

The finding that non-stem cells can change function indicates that it may be possible to produce neural cells for transplantation that specifically match the human patient’s genetics. The cells swapped function over just three weeks with the assistance of specialized transcription factors in a process known as transdifferentiation.

This process is advantageous, in contrast with the process of inducing pluripotency in a cell, because it produces a homogeneous population of converted cells. Induced pluripotency can result in leftover pluripotent cells that, if transplanted into a patient, may cause cancer because the cells can still differentiate their function.

While the Stanford research group is working toward replicating the cell-swapping ability with human cells, the process and its resulting cells are far from being tested with human transplantation subjects due to the preliminary nature of the research. The ability to produce rapidly large quantities of neural cells in a laboratory setting, however, is immediately valuable for research into diseases and drug targeting, the study said.

The Stanford research group has previously shown skin cells of both mice and humans to be capable of direct conversion into functioning neurons.

Marius Wernig, assistant professor of pathology, is the lead author of the study, which was published online in the Proceedings of the National Academy of Sciences on Jan. 30. The first author is Ernesto Lujan, a graduate student in genetics. Wernig is a member of Stanford’s Institute for Stem Cell Biology and Regenerative Medicine.

–Alice Phillips