Category Archives: Pluripotent Stem Cells

Hair-Bearing Skin Generated from Pluripotent Stem Cells

Blog readers keep giving me breaking news faster than Google Alerts, and I am appreciative. This time, thanks to “Del”, even if his input has forced me to write two posts in one day. Update: The podcast for this news is here.

Pluripotent Stem Cells and Hair Growth

Yesterday a very important study was published in Nature Magazine. It is titled “Hair-bearing human skin generated entirely from pluripotent stem cells”. The scientists behind this research took 6 years to complete and publish their work.

The study has numerous co-authors from a few medical centers and universities based in the US. The lead author is Dr. Jiyoon Lee, while the correspondence author is Dr. Karl Koehler. The latter works at Boston Children’s Hospital as well as Harvard Medical School. Moreover, Dr. Koehler’s lab has its own site, on which he published a post about these findings.

Dr. Karl Koehler via Twitter

Pluripotent Stem Cells to Grow Hair
Pluripotent Stem Cells to Grow Hair. From Dr. Karl Koehler’s Twitter feed.

From Skin Organoids to Hair

In this latest research, undifferentiated human stem cells were successfully coaxed into developing skin-like organoids in vitro. When these human-derived structures were grafted onto immuno-compromised bald mice, the rodents produced robust (albeit shorter length) hair.

Note that in 2015, Dr. Alexey Terskikh and his team used pluripotent stem cells from humans to create dermal papilla type cells. These were then injected into hairless mice and grew hair.

Pluripotent Stem Cells Hair Growth
Pluripotent Stem Cells and Hair Growth — Nature Magazine.

In this new work, the scientists generated near-complete skin organoids first that ultimately resulted in pigmented hair. The skin cells grew in a sphere and were “fed” with various chemicals and growth factors (such as BMP4 and FGF2) for 4-5 months. Both the dermis and epidermis skin layers were grown successfully.

If this work goes through successful clinical trials, it will essentially mean a cure for hair loss. Nevertheless, the global media has largely ignored this research, with the UK’s Mirror being a notable exception. And as always, the Daily Mail too.

Cotsarelis Rises Again

Prolific blog commentator “MJones”‘ favorite hair loss researcher and fellow Alexander the Great progeny Dr. George Cotsarelis has been missing in action of late. However, this new research is so significant, that Dr. Cotsarelis and Dr. Leo Wang wrote a detailed article summarizing it in Nature Magazine.

Per the two doctors, this study represents a major step towards a cure for baldness in humans. They are confident that this research will eventually see its promise realized. This technique makes it possible to produce human hair without having to take any donor hair from the human.

Moreover, individuals who have major wounds, scars and genetic skin diseases will all benefit from revolutionary new treatments based on this research. That is if it comes to clinic of course.

In these times of pandemics, protests and riots, it is great to see Dr. Cotsarelis’ still unabated optimism. Ironically, for “MJones”, the glass has always been half empty.

Further reading: An excellent 2019 paper summarizing tissue engineering strategies for human hair follicle regeneration.

Pluripotent Stem Cells Used to Grow Human Hair in Mice

Scientists led by Dr. Alexey Terskikh  at the California-based Sanford-Burnham Medical Research Institute published a groundbreaking study yesterday that was widely covered by the media.  Some interesting takes here, here and here. The first of those three links has some interesting feedback from Histogen’s CEO Dr. Gail Naughton.

In summary, these scientists used pluripotent stem cells from humans to create dermal papilla type cells that were then injected into hairless mice.  Lo and behold, the mice started to grow human hair!  I do not see any strong reason preventing the same from working from human->human (as long as its the same human). However, Dr. Terskikh stated that he is still looking for partners “to implement this final step”, and clinical trials will then tack on a few more years to this procedure finally coming to market.

One thing that I like about the Sanford-Burnham Medical Research Institute is that it is a non-profit organization.  I wonder what conditions a for-profit partner would set for providing research funding? We always seem to have issues when private sector companies purchase rights to new technology in the hair loss world, since each new clinical trial phase progression is then dependent on one particular company’s internal decision making and funding availability. If they do not feel that a product will make them at least $xyz, they often even cancel further research despite successful outcomes from initial trials.

In any case, going back to this study, the  artificial dermal papillae cells were grown from pluripotent stem cells.  Such cells can be derived from human embryos (controversial) or a patient’s own skin cells (not controversial).  According to Dr. Terskikh, per one of the articles I linked above:

Patients can donate their own iPS cells, which can be grown into the replacement dermal papillae in “unlimited” quantities.”

Note: iPS (or IPSC) stands for induced pluripotent stem cells, which are generated from adult cells (as opposed to embryonic pluripotent stem cells, which are derived from early stage embryos).

Besides the above advantage, another key benefit of this stem cell derived process is that it overcomes the ongoing problems researchers have had in trying to multiply existing human dermal papilla cells outside the body and then re-injecting them into the scalp.  The dermal papilla cells largely seem to  lose their hair-inducing properties when kept outside the body.  In fact in this very study the authors tried three experiments:

  1. Transplanting human dermal papillae cells taken from adult scalps to the mice.  Result = insignificant number of hairs generated.
  2. Transplanting just human skin cells to the mice. Result = insignificant number of hairs generated.
  3. Transplanting dermal papilla cells grown/derived from human embryonic stem cells to the mice.   Result = significant new hair generation!

Besides Dr. Terskikh, the principal author of the paper is Dr. Ksenia Gnedeva.  While the former has done work in many different areas (largely related to stem cells), the latter has focused a lot more on hair related research.  It seems like both of these researchers have published some of their research in Russian.  This year, I hope to try and write more about hair loss research that is being conducted in countries such as Russia and China, but is not being published in the English language.  Perhaps I might have to hire some local students from those countries to help me?

Update: Ironically enough, someone fluent in Russian was thinking along the same lines as me and actually managed to interview one of the article’s authors based in Russia.  See more on Bald Truth Talk forum member “Bald Russian”‘s phone interview with Ekaterina Vorotelya.  Wish US-based researchers were as forthcoming!