Skip to content

Study verifies how stem cells get activated to produce new hair.

Adult stem cells provide the body with a reservoir from which damaged or used up tissues can be replenished. In organs like the intestines and skin, which need constant rejuvenating, these stem cells are dividing frequently. In other body structures, such as the hair follicles, they don’t reproduce until they receive signals from their surroundings that it’s time to regenerate; this is known as a quiescent state.

It makes intuitive sense that stem cells, being such a valuable resource, would be used sparingly.  However, scientists have limited understanding of how their quiescence is regulated, being unsure of its precise biological function. Now, a study from researchers at The Rockefeller University provides insights into the biological signals that make hair follicle stem cells oscillate between states of quiescence and regenerative activity.  The opensource study is published in the journal PNAS.

Previous studies show that a key provider of regulatory signals that balance stem cell quiescence and activity is the stem cell environment. Termed the ‘niche,’ it provides a residence for stem cells, and interacts with stem cells to regulate their behaviour and properties. Niche signals can originate from the immediate neighbours of the stem cells, or from the macroenvironment of the organ.  Earlier studies for the lab showed that when mice age, the old fat in their skin produces higher levels of a secreted signal, called BMP.  This signal acts as a molecular brake on the hair follicle stem cells, causing them to spend much longer times in quiescence.  The current study identified a stem cell gene that is activated by BMP signaling and showed that when this gene, Foxc1, is missing the stem cells grow hairs at dramatically shorter intervals.

The current study utilised mice that lack FOXC1, by disabling the gene that produces this protein they observed that the animals’ hair follicle stem cells spent more time growing hairs and less time in quiescence. Results show that over the course of nine months, while hair follicles from normal mice grew four new hairs, those from the FOXC1 knockout mice had already made new hairs seven times.  Data findings show that the knockout stem cells enter an overactive state in which they can’t establish quiescence adequately.

Results show that in the absence of FOXC1, hair follicles always had only one hair despite having made new hairs seven times. The group explain that this is because these hair follicles could not retain their old bulges, though they generated a new bulge without a problem. They go on to add that as the stem cells started proliferating more, they became less able to stick together, and as a result their old bulges did not stay properly tethered to the hair follicle when the newly growing hair pushed past it. Findings show that since the bulge emits quiescence signals, its loss activated the remaining stem cells even faster.

The team surmise that as hair follicle stem cells influence the behaviour of melanocyte stem cells, which co-inhabit the bulge niche; when the numbers of hair follicle stem cells declined with age, so too did the numbers of melanocyte stem cells, resulting in premature greying of whatever hairs were left.  For the future, the researchers state that not much is known about naturally occurring hair loss with age, however, these balding knockout mice may provide a model to study it.

Source: The Rockefeller University


Hair follicle stem cells lacking the protein FOXC1 can only retain one old bulge in their hair follicles, while normal stem cells can keep up to four. Credit: The Laboratory of Mammalian Cell Biology and Development at Rockefeller University/PNAS.
Hair follicle stem cells lacking the protein FOXC1 can only retain one old bulge in their hair follicles, while normal stem cells can keep up to four. Credit: The Laboratory of Mammalian Cell Biology and Development at Rockefeller University/PNAS.

Healthinnovations View All

Michelle Petersen is the founder of Healthinnovations, having worked in the health and science industry for over 21 years, which includes tenure within the NHS and Oxford University. Healthinnovations is a publication that has reported on, influenced, and researched current and future innovations in health for the past decade.

Michelle has been picked up as an expert writer for Informa publisher’s Clinical Trials community, as well as being listed as a blog source by the world’s leading medical journals, including the acclaimed Nature-Springer journal series.

Healthinnovations is currently indexed by the trusted Altmetric and PlumX metrics systems, respectively, as a blog source for published research globally. Healthinnovations is also featured in the world-renowned BioPortfolio,, the life science, pharmaceutical and healthcare portal.

Most recently the Texas A&M University covered The Top 10 Healthinnovations series on their site with distinguished Professor Stephen Maren calling the inclusion of himself and his team on the list a reflection of “the hard work and dedication of my students and trainees”.

Michelle Petersen’s copy was used in the highly successful marketing campaign for the mega-hit film ‘Jumanji: The Next Level, starring Jack Black, Karen Gilian, Kevin Hart and Dwayne ‘The Rock’ Johnson. Michelle Petersen’s copywriting was part of the film’s coverage by the Republic TV network. Republic TV is the most-watched English language TV channel in India since its inception in 2017.

An avid campaigner in the fight against child sex abuse and trafficking, Michelle is a passionate humanist striving for a better quality of life for all humans by helping to provide traction for new technologies and techniques within healthcare.

One thought on “Study verifies how stem cells get activated to produce new hair. Leave a comment

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.