Tissues of the body originally form when “naïve” undifferentiated embryonic stem cells differentiate to form the “mature” cells of specific tissues: liver cells, brain cells, skin cells, and so on.
The mature cells are then locked in their differentiated forms, as if they met their fate.
I recently mentioned that Yamanaka and Gurdon were awarded the Nobel Prize in Medicine in 2012 for their surprising findings about dedifferentiation. Through direct genetic modification of nuclear function, mature cells can be reprogrammed to return to naïve stem-cell states. These dedifferentiated cells are pluripotent and can differentiate again and form a variety of mature cell types.
The rejuvenated cells regain the naïve properties of embryonic stem cells!
In January this year, an article published in Nature reported that the genetic reprogramming can be achieved more easily, without direct nuclear manipulation.
All you need to do to dedifferentiate mature cells, according to this article, is to subject them to stress: like an acid environment. Not all but some of the mature cells will be freed from their fate as liver or skin cells and return to naïve pluripotent states.
An easy to read summary can be found in BioEdge, and here is a link to the article:
Using mature cells to create stem cells with properties of embryonic stem cells might thus be easier than expected. In fact, the new findings weren’t even made in a stem-cell laboratory.
The ethical responses to the findings are not as thrilling as the findings. Some welcome the possibility of creating “ethical stem cells” that avoid the controversy about embryonic stem cells. Others see “new ethical issues” on the horizon.
These responses are characteristic of a routine view of ethical assessment as a static one-way process: ethicists assess others. But these findings indicate that processes in the opposite direction are possible as well, since they seem to challenge ethical assumptions about the unique function of the embryo.
I’m tempted to extend Thomas Kuhn’s notion of scientific revolutions to ethics. The new findings could function as anomalies for ethically paradigmatic ways of thinking about the embryo.
As stress turns mature cells into naïve pluripotent stem cells, these findings could stress some ethicists to return to more open-minded states that in the future can differentiate in new and unexpected directions.