As one of the follically-challenged, any new breakthroughs in the area of hair regeneration will generally get my attention. When stem cells first started to gain widespread media attention I, no doubt like many others, thought a full head of hair was just around the corner. But despite numerous developments, years later my dome is still of the chrome variety. Providing the latest cause for cautious optimism, researchers have now developed a way to generate a large number number of hair-follicle-generating stem cells from adult cells.

In what they claim is a world first, researchers from the University of Pennsylvania (UPenn) and the New Jersey Institute of Technology have developed a technique to convert adult human stem cells into epithelial stem cells (EpSCs).

By adding three genes to human skin cells called dermal fibroblasts that live in the dermis layer of the skin and generate connective tissue, a team led by Xiaowei "George" Xu, MD, PhD, at the Perelman School of Medicine was able to convert them into induced pluripotent stem cells (iPSCs). The iPSCs, which have the ability to differentiate into any cell type, were then converted into epithelial stem cells (EpSCs) that are normally found at the bulge of hair follicles.

Through careful control of the timing of delivery of growth factors to the cells, the researchers say they were able to turn over 25 percent of the iPSCs into EpSCs in 18 days. When they then mixed these EpSCs with mouse follicular inductive dermal cells and grafted them onto the skin of immunodeficient mice, functional human epidermis and follicles similar to hair follicles were produced.

Hair shafts (arrowheads) formed by induced pluripotent stem cell-derived epithelial stem cells compared to mouse hair (arrows) (Photo: Ruifeng Yang, Perelman School of Medicine, University of Pennsylvania)

"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," said Xu, who added that these cells have many potential applications, including wound healing, cosmetics, and hair regeneration.

But some hurdles still need to be jumped before I make my first trip to the hairdresser in a decade. Xu points out that when a person loses hair, they lose not only epithelial cells, but also a kind of adult stem cell called dermal papillae. "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."

On a positive note, researchers from the Tokyo University of Science have reported promising results in reconstructing hair follicle germs from adult epithelial stem cells and cultured dermal papilla cells, so even though we haven't rounded the corner yet,it definitely seems to be getting closer.

The teams research is published in the journal Nature Communications.

Source: University of Pennsylvania