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.

Stem cell stories that caught our eye: new baldness treatments?, novel lung stem cells, and giraffe stem cells

Novel immune system/stem cell interaction may lead to better treatments for baldness. When one thinks of the immune system it’s usually in terms of the body’s ability to fight off a bad cold or flu virus. But a team of UCSF researchers this week report in Cell that a particular cell of the immune system is key to instructing stem cells to maintain hair growth. Their results suggest that the loss of these immune cells, called regulatory T cells (Tregs for short), may be the cause of baldness seen in alopecia areata, a common autoimmune disorder and may even play a role in male pattern baldness.

Alopecia, a common autoimmune disorder that causes baldness. Image: Shutterstock

While most cells of the immune system recognize and kill foreign or dysfunctional cells in our bodies, Tregs act to subdue those cells to avoid collateral damage to perfectly healthy cells. If Tregs become impaired, it can lead to autoimmune disorders in which the body attacks itself.

The UCSF team had previously shown that Tregs allow microorganisms that are beneficial to skin health in mice to avoid the grasp of the immune system. In follow up studies they intended to examine what happens to skin health when Treg cells were inhibited in the skin of the mice. The procedure required shaving away small patches of hair to allow observation of the skin. Over the course of the experiment, the scientists notice something very curious. Team lead Dr. Michael Rosenblum recalled what they saw in a UCSF press release:

“We quickly noticed that the shaved patches of hair never grew back, and we thought, ‘Hmm, now that’s interesting. We realized we had to delve into this further.”

That delving showed that Tregs are located next to hair follicle stem cells. And during the hair growth, the Tregs grow in number and surround the stem cells. Further examination, found that Tregs trigger the stem cells through direct cell to cell interactions. These mechanisms are different than those used for their immune system-inhibiting function.

With these new insights, Dr. Rosenblum hopes this new-found role for Tregs in hair growth may lead to better treatments for Alopecia, one of the most common forms of autoimmune disease.

Novel lung stem cells bring new insights into poorly understood chronic lung disease. Pulmonary fibrosis is a chronic lung disease that’s characterized by scarring and changes in the structure of tiny blood vessels, or microvessels, within lungs. This so-called “remodeling” of lung tissue hampers the transfer of oxygen from the lung to the blood leading to dangerous symptoms like shortness of breath. Unfortunately, the cause of most cases of pulmonary fibrosis is not understood.

This week, Vanderbilt University Medical Center researchers report in the Journal of Clinical Investigation the identification of a new type of lung stem cell that may play a role in lung remodeling.

Susan Majka and Christa Gaskill, and colleagues are studying certain lung stem cells that likely contribute to the pathobiology of chronic lung diseases.  Photo by: Susan Urmy

Up until now, the cells that make up the microvessels were thought to contribute to the detrimental changes to lung tissue in pulmonary fibrosis or other chronic lung diseases. But the Vanderbilt team wasn’t convinced since these microvessel cells were already fully matured and wouldn’t have the ability to carry out the lung remodeling functions.

They had previously isolated stem cells from both mouse and human lung tissue located near microvessels. In this study, they tracked these mesenchymal progenitor cells (MPCs) in normal and disease inducing scenarios. The team’s leader, Dr. Susan Majka, summarized the results of this part of the study in a press release:

“When these cells are abnormal, animals develop vasculopathy — a loss of structure in the microvessels and subsequently the lung. They lose the surfaces for gas exchange.”

The team went on to find differences in gene activity in MPCs from healthy versus diseased lungs. They hope to exploit these differences to identify molecules that would provide early warnings of the disease. Dr. Majka explains the importance of these “biomarkers”:

“With pulmonary vascular diseases, by the time a patient has symptoms, there’s already major damage to the microvasculature. Using new biomarkers to detect the disease before symptoms arise would allow for earlier treatment, which could be effective at decreasing progression or even reversing the disease process.”

The happy stem cell story of Mahali the giraffe. We leave you this week with a feel-good story about Mahali, a 14-year old giraffe at the Cheyenne Mountain Zoo in Colorado. Mahali had suffered from chronic arthritis in his front left leg. As a result, he could not move well and was kept isolated from his herd.

Giraffes at Cheyenne Mountain Zoo. Photo: Denver Post

The zoo’s head veterinarian, Dr. Liza Dadone, decided to try a stem cell therapy procedure to bring Mahali some relief and a better quality of life. It’s the first time such a treatment would be performed on a giraffe. With the help of doctors at Colorado State University’s James L. Voss Veterinary Teaching Hospital, 100 million stem cells grown from Mahali’s blood were injected into his arthritic leg.

Before treatment, thermograph shows inflammation (red/yellow) in Mahali’s left front foot (seen at far right of each image); after treatment inflammation resolved (blue/green). Photos: Cheyenne Mountain Zoo

In a written statement to the Colorado Gazette, Dr. Dadone summarized the positive outcome:

“Prior to the procedure, he was favoring his left front leg and would lift that foot off the ground almost once per minute. Since then, Mahali is no longer constantly lifting his left front leg off the ground and has resumed cooperating for hoof care. A few weeks ago, he returned to life with his herd, including yard access. On the thermogram, the marked inflammation up the leg has mostly resolved.”

Now, Dr. Dadone made sure to state that other treatments and medicine were given to Mahali in addition to the stem cell therapy. So, it’s not totally clear to what extent the stem cells contributed to Mahali’s recovery. Maybe future patients will receive stem cells alone to be sure. But for now, we’re just happy for Mahali’s new lease on life.