Epithelial Stem Cells

Progress towards hair cloning may have just have shifted up another gear thanks to scientists at the University of Pennsylvania and the New Jersey Institute of Technology. The breakthrough study published January 28th, 2014 is the first to show the successful transformation of adult human skin cells into quantities of epithelial stem cells necessary for hair regeneration.

The researchers, led by Dr. Xiaowei “George” Xu, started with human skin cells called dermal fibroblasts, then transformed those into a type of stem cell called induced pluripotent stem cells (iPSCs). These were then transformed into epithelial stem cells (EpSCs). This important step had never been achieved before in either humans or mice. The epithelial stem cells were combined with mouse dermal cells, that can be induced to form hair follicles, and then grafted on a mouse host. The epithelial cells and dermal cells then grew to form a functional human epidermis and follicles structurally similar to human hair follicles. The exhibits that accompany the study include photographic evidence of human hairs.

The main breakthrough in the study came when the research team carefully timed the addition of growth factors to the iPSCs. Previous research showed the ability for iPSCs to be transformed into a common type of cell found in the skin called keratinocytes. By timing the addition of the growth factors, they were able to turn over 25% of the iPSCs into epithelial stem cells in a little more than two weeks. This “mass production” of epithelial stem cells holds tremendous promise for the development of a hair regeneration treatment. On this development, Dr. Xu said, “This is the first time anyone has made scalable amounts of epithelial stem cells that are capable of generating the epithelial component of hair follicles.”

As noted in a University of Pennsylvania press release on the news, there are two types of stem cell that are critical in hair follicles: epithelial stem cells and dermal papillae. While this study only achieved success in the creation of epithelial stem cells, we have extensively covered Dr. Angela Christiano’s ground-breaking research into the induction of dermal papillae into hair follicles (a process she calls hair follicle neogenesis).

“When a person loses hair, they lose both types of cells. We have solved one major problem, the epithelial component of the hair follicle. We need to figure out a way to also make new dermal papillae cells, and no one has figured that part out yet,” said Dr. Xu.

Once that it is done, we must also find a way to have the epithelial and dermal components of the follicle interact before one will be able to produce cosmetically useful hair. But with each successive breakthrough, the time when a scientist can use hair cloning techniques to regenerate human hair, and the surgeon can implant them into a person’s scalp, draws ever closer.

Reference
Yang R, Zheng Y, Xu X. Generation of folliculogenic human epithelial stem cells from induced pluripotent stem cells. Nature Communications. 2014.

Posted by Robert M. Bernstein M.D.