A hair raising tale

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For many men, losing their hair is not just something that happens with age, it’s traumatic. A survey of men from the UK, France, Germany, Italy and Spain found that more than 70% of men who reported losing their hair said it was an important feature of their image, and 62% agreed that hair loss could affect self-esteem. So, while a scientist who comes up with a way to prevent hair loss may not win a Nobel Prize, they will certainly get the undying gratitude of millions of men, and some women, around the world.

Now a team at Northwestern Medicine may just have found some clues as to why it happens, and some clues on how to stop it.

As we age our hair follicles go through a cycle of growth and death. As older hairs die there are stem cells in the hair follicles that produce new, replacement hair follicle cells. In this study, which was done in older male mice, the researchers found that as the mice age the stem cells in the hair start to lose the stickiness that helps them remain in the hair follicles. Without that stickiness they drift outside of the protective environment and can’t survive.

As Dr. Rui Yi, lead author of the study says in a news release; no hair stem cells, no hair replacements. “The result is fewer and fewer stem cells in the hair follicle to produce hair. This results in thinning hair and ultimately baldness during aging.”

Happily, the team also discovered two genes that seem to play a key role in generating the stickiness the cells need to stay in the follicle. They are now trying to reinstate those genes to see if that can reverse hair loss.

While this was done in mice the researchers say there are a lot of similarities between mice and humans in hair and stem cells.

One can only hope.

The study is published in the journal Nature Aging.

Could stem cells help reverse hair loss?

I thought that headline would grab your attention. The idea behind it grabbed my attention when I read about a new study in the journal Cell Metabolism that explored that idea and came away with a rather encouraging verdict of “perhaps”.

The research team from the University of Helsinki say that on average people lose 1.5 grams of hair every day, which over the course of a year adds up to more than 12 pounds (I think, sadly, this is the one area where I’m above average.) Normally all that falling hair is replaced by stem cells, which generate new hair follicles. However, as we get older, those stem cells don’t work as efficiently which explains why so many men go bald.

In a news release, lead author Sara Wickstrom says this was the starting point for their study.

“Although the critical role of stem cells in ageing is established, little is known about the mechanisms that regulate the long-term maintenance of these important cells. The hair follicle with its well understood functions and clearly identifiable stem cells was a perfect model system to study this important question.”

Previous studies have shown that after stem cells create new hair follicles they essentially take a nap (resume a quiescent state in more scientific parlance) until they are needed again. This latest study found that in order to do that the stem cells have to change their metabolism, reducing their energy use in response to the lower oxygen tissue around them. The team identified a protein called Rictor that appears to be the key in this process. Cells with low levels of Rictor were less able to wake up when needed and generate more hair follicles. Fewer replacements, bigger gaps in the scalp.

The team then created a mouse model to test their theory. Sure enough, mice with low or no Rictor levels were less able to regenerate hair follicles. Not surprisingly this was most apparent in older mice, who showed lower Rictor levels, decreased stem cell activity and greater hair loss.

Sara Wickstrom says this could point to new approaches to reversing the process.

“We are particularly excited about the observation that the application of a glutaminase inhibitor was able to restore stem cell function in the Rictor-deficient mice, proving the principle that modifying metabolic pathways could be a powerful way to boost the regenerative capacity of our tissues,”

It’s early days in the research so don’t expect them to be able to put the Hair Club for Men out of business any time soon. But a follicle-challenged chap can dream can’t he.