Hair Today, Muscle Tomorrow
That headline is a bit misleading, because it’s not actually about hair, but there’s more news on stem cells from hair follicles. (Almost all the rest of the news is about the upcoming Senate vote—lots of people have opinions.) According to a press release
, Researchers at the University of Pennsylvania School of Medicine have been able to differentiate stem cells obtained from scalp tissue into several kinds of cells. Hair follicles are already known to be a source of stem cells; in this research, the scientists looked at the stem cell niche, known as the hair follicle bulge. (Once again, the niche is showing its importance as part of what influences stem cell development.) They were able to obtain a new kind of stem cell from the scalp tissue and then cultured it under the same conditions as they would embryonic stem cells. The cells grew into masses called hair spheres, from which stem cells were isolated.
The researchers were then able to differentiate them into nerve cells, smooth muscle cells, and melanocytes (skin pigment cells), among other types by growing them on a medium with appropriate growth factors. The most successful of these was the smooth muscle cell type; 80% of the differentiated cells grew into smooth muscle tissue. In contrast, only 10% of the cells on the nerve medium grew dendrites and expressed neuronal proteins. They also produced neurotransmitter glutamate but not dopamine.
Besides demonstrating the multipotency of stem cells from the follicles, this research also shows that embryonic stem cell type medium can be used on non-embryonic stem cells to cause them to grow. At this point if I were a scientist I’d be using embryonic growth medium whenever possible—and if I were a biotech company, I’d be developing a scaffolded or multidimensional culture. It seems like the more that is learned about stem cells, the more important and complex the involvement of the environment is.