Category Archives: University of Southern California

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.

USC — How the Gene Wnt7b Activates Hair Growth

This year has witnessed so much new and interesting hair loss related research, that it is hard to believe that in just this one month three universities published major new findings!

I already covered the news from U Penn (hirsutism) in the US and King’s College (skin cells) in the UK in earlier posts this month. Those two findings were widely covered in the media. However, perhaps I should have covered research from a much lesser known team from University of Southern California in the US first.

USC scientist Krzysztof Kobielak and postdoctoral fellow Eve Kandyba along with other colleagues have published three papers this year related to hair loss.

Wnt7b and Hair Growth

The latest of these three (published in November in the journal Stem Cells, but publicized this month) focuses on how the gene Wnt7b activates hair growth.

Earlier work by this team entailed research on how reduced BMP signaling and increased Wnt signaling activates hair growth, while increased BMP signaling and decreased Wnt signaling keeps hair follicle stem cells (hfSCs) in a resting state. Much more can be read here.

It is also encouraging that this project has received government funding via the National Institute of Arthritis and Musculoskeletal and Skin Diseases.