Hope for Reversing Hair Loss
One potential approach to reversing hair loss uses stem cells to regenerate the missing or dying hair follicles but it hasn't been possible to generate sufficient numbers of hair-follicle-generating stem cells. Now, however, researchers at the University of Pennsylvania School of Medicinehave come up with a method for for converting adult cells into epithelial stem cells. When the scientists implanted these cells into mice with compromised immune systems, the cells regenerated the different cell types of human skin and hair follicles and even produced a structurally recognizable hair shaft. This discovery raises the possibility that the cells may eventually enable hair regeneration in people. The study was published in the journal Nature Communications.
A release from the university notes that Xiaowei "George" Xu, MD, PhD, and colleagues started with human skin cells called dermal fibroblasts. By adding three genes, they converted those cells into induced pluripotent stem cells (iPSCs), which have the capability to differentiate into any cell types in the body. They then converted the iPS cells into epithelial stem cells, normally found at the bulge of hair follicles.
Starting with procedures other research teams had previously worked out to convert iPSCs into keratinocytes, Xu's team demonstrated that by carefully controlling the timing of the growth factors the cells received, they could force the iPSCs to generate large numbers of epithelial stem cells. In the Xu study, the team's protocol succeeded in turning over 25% of the iPSCs into epithelial stem cells in 18 days. Those cells were then purified using the proteins they expressed on their surfaces.
The release quotes XU as saying, "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." He adds that those cells have many potential applications including wound healing, cosmetics, and hair regeneration.