Category Archives: Cheng-Ming Chuong

One Reason Hair Thins is Because Some of it Turns into Skin

Update: A blog reader from Brazil sent me something very interesting yesterday.  Apparently, there was a study published less than two months ago that concluded that chronic inflammation was turning eye cells into skin cells!  Read more here.

Update: Below news now also covered in many other sources, including Time, Wired and of course the Daily Mail.


Today, the prestigious Science Magazine published two new studies related to hair loss and stem cells. They also had a brief summary on the link between aging, stem cells and alopecia, authored by Dr. Cheng-Ming Chuong from USC who I have mentioned on this blog before.  The studies were not widely covered in the general media.   In a rarity, the UK’s gossip rag Daily Mail seems to be sleeping when compared to its usually immediate and superb coverage or hair loss cure research and celebrity hair loss related news.  Another UK-based paper, The Guardian, did cover these two studies and a lot of people have already made mostly nonsensical comments to that article.  (Note that the author of this article seems to have typed COL17A1 as COL17AL, and some of the text in there seems like it was written by a non-scientist.  He also forgets to mention that one of the studies also entailed experiments in humans).

The first study (thanks to commentator “nosyu” for letting me know) from Japan has the somewhat difficult to understand title “Hair follicle aging is driven by transepidermal elimination of stem cells via COL17A1 proteolysis.”  For non-scientists, the contents of that study are not very easy to understand without spending some time googling the various technical terms listed in there.  However, an easier to understand article analyzing the above study’s findings concludes that “One reason your hair is thinning is because some of it turns into skin.”  The study also discusses shedding of epidermal keratinocytes from the skin surface.  A lot of people complain about dandruff, itching and dermatitis throughout their scalp while they are slowly balding, and I have had those problems many times in the past decade.  Nizoral and sunshine have both helped me tackle those problems, but I can never seem to go for more than a few days without at least some itching and skin shedding.  Note that a Japanese article on this study actually mentions the word “dandruff” in there when you translate to English.

The study authors found that hair follicles in women over age 55 were smaller and with lower levels of Collagen 17A1 (see more on COL17A1 here).  It is good to see a study that is devoted to female hair loss sufferers.  Moreover, one of the lead authors of the study is also a female by the name of Dr. Emi Nishimura.  The researchers also engineered mice to lack the COL17A1 gene, and found that these mice then had no follicle-generating cells.

The second study is titled “Foxc1 reinforces quiescence in self-renewing hair follicle stem cells.”  Foxc1 (also known as Forkhead box C1) belongs to the Forkhead family of proteins and transcription factors.  It seems like Foxc1 regulates the hair growth cycle, and perhaps manipulating this in future could prevent balding.

Quorum Sensing: Hair Plucking to Grow New Hair

Yet again (see my 2013 blog post), scientists from the University of Southern California (USC) surprised us this week  by publishing a groundbreaking study related to hair. This one was on how strategic plucking induces new hair growth — in mice :-( The work was led by Dr. Cheng-Ming Chuong and published in the prestigious Cell magazine, giving it significant credibility. You can see the entire paper on Dr. Chuong’s website.

Hair Plucking and Quorum Sensing

I am not sure why such a simple experiment has not yet been attempted on humans. I was not too motivated to write this post several days ago when the news first came out and I read the word “mouse” in there. In fact I have not even bothered to read most of the pages in hair loss forum threads related to this news yet.

Here are some links to this important story: link1 from the USC website; link 2 from the LA times where they discuss macrophages; and link 3 from BBC where they mention a potential cream or injection for this. The results varied significantly depending on the number of follicles plucked and the area from which they were plucked.

When done correctly, new hair even grew outside the plucked area. This type of phenomenon is seen in many areas of biology and is termed as “Quorum Sensing“.  The luckiest mouse had 200 hairs plucked and grew back 1,300 hairs. A great summary of growing hair via plucking can be found here.

One of the quotes from the first link in the last paragraph was interesting:

As a dermatologist, Chen knew that hair follicle injury affects its adjacent environment, and the Chuong lab had already established that this environment in turn can influence hair regeneration.

I wonder if this result from plucking is then also related to some extent to other injury type phenomena that can result in new hair growth such as:

  1. Numerous anecdotal reports of people seeing more hair on a limb after a cast or splint has been removed months after an injury.
  2. Dermarolling type intentional injuries to hair follicles.
  3. Mechanotherapy type intentional injuries to hair follicles.
  4. And maybe even lasers (LLLT) partly working by causing some injury (heating) to hair follicles?

If I was a bit more driven and had more spare time, I would try to experiment with plucking my body hair in both my arms and maybe legs too. I would try different amounts/densities and areas just as in the mouse experiment and take lots of photos.  If any one area became thick with new body hair, I would be quite surprised.