We have previously blogged about the real potential stem cells represent in the quest to find a cure for baldness but a new clinical study finally proves that stress is to blame for grey hairs and the key to the problem is stem cells - stress a study has found, kills off stem cells.
For years there has been an anecdotal belief that high levels of stress are linked to the greying of hair, now following a study with mice researchers have confirmed there is some truth in it.
The US team found that the appearance of grey hairs could be the result of a depletion of stems cells.
Hair and skin colour is controlled by melanocyte stem cells which are found in the base of hair follicles - an area known as the bulge.
Dr Mayumi Ito and colleagues from New York University discovered stress not only causes stem cells to leave, but when they do they are not replaced, and therefore the hairs turn white.
The scientists investigated the stem cell behaviour by looking at how they leave hair follicles to repair damaged skin.
“Stress hormones promote melanocyte migration from hair follicles to damaged skin,” Dr Ito said.
"We thought it would be interesting to speculate that excessive stress might promote this migration too much."
The study has fascinated scientists from around the world, including Associate Professor Rick Sturm from the University of Queensland, Australia.
He said: "Normally stem cells only stay in the bulge region.
"If you lose the stem cells from the bulge region, the hair follicles in that area would become white."
Grey hair caused by ageing is the result of exhaustion and loss of melanocyte stem cells, and stress could cause similar results.
The study may also point to new methods of treatment for skin pigmentation disorders.
Dr Ito added: "If we can know more about how melanocytes migrate, we may be able to improve the treatment of other skin pigmentation disorders."
The study was reported in the Nature Medicine journal.
Balding men could also be offered hope of waking their 'sleeping' hair
Scientists have discovered that hair follicles in people who are balding are trapped in a "sleeping" state and are now developing a new treatment to combat baldness.
It sounds more like an explanation that would be used by nursery children than respected scientists, but researchers have found that rather than losing their hair altogether, people who are going bald are suffering from "sleeping" hair follicles.
Trichologists have discovered that hair follicles on the scalp can become trapped in a resting state where they do not grow new hair, leading to thinning.
They now claim to have identified a way of waking the follicles up again to help restore a fuller head of hair to people who are going bald.
Unfortunately they may not be able to delay the balding process forever, as eventually the hair follicles lose the ability to make new hair, but for those who are starting to get a bit thin on top, it may help stave of the need for embarrassing wigs, comb overs or hair transplants.
Dr Bruno Bernard, head of hair biology at L'Oreal in Paris who carried out the research, has now announced that the company are developing a new treatment that can be applied to the scalp in a shampoo or cream to help encourage hair to grow again.
He said: "Hair follicles exist in two stable states – either an active state or a dormant state. From time to time, they will jump from one state to another.
"Some of the follicles are just resting in the dormant state and are waiting for the right signal to make new hair. They are in a latency period. If you can reduce this latency period, you will have more hair.
"We have identified a compound and we are going to make a formulation of it that can be applied to the scalp to wake the follicle up from its sleeping state to the active state."
Up to half of all men suffer from androgenic alopecia, the most common cause of hair loss and thinning in humans. It is estimated that around eight million women in the UK also suffer excessive hair loss to some degree.
Typically hair strands grow continually for a period of up to four years before the follicles switch to a dormant state and the strand of hair falls out. During this dormant period, stem cells in the skin begin the processes needed to grow new hair.
In people who are going bald, however, this process can stall and new hair does not form.
Scientists working with Dr Bernard at L'Oreal believe they have identified why this happens. They have found two reservoirs of stem cells help are responsible for creating new hair, one that is near the surface of the skin and one that is deeper in the layers of the skin.
The bottom reservoir of stem cells, called CD34+ cells, are in an environment that is low in oxygen, known as hypoxia, which helps to keep the stem cells in a healthy condition.
Dr Bernard, who presented the findings at the European Hair Research society in Barcelona, said that in people who are going bald, the levels of oxygen around these stem cells have changed, meaning they work less efficiently and so preventing the creating of new hair.
"The stem cells can sense the amount of oxygen around them," he said. "We have identified molecules that mimic the effect of hypoxia on the stem cells. It means we can push the empty hair follicles to make new hair fibres faster."
Banking on future cures
For decades, doctors have harnessed the unique ability of stem cells to treat leukemia and genetic blood diseases. But now, researchers are discovering that these cells have the power to heal, to fight disease, and to regenerate damaged or aging tissue throughout the body. To fully understand why they hold the potential to change your child’s medical future, get to know more about stem cells.
STEM CELL BASICS
Ordinary cells in your body replicate to make new cells of the same type - blood cells make more blood cells, skin cells make more skins cells and so on. However, there is another type of cell, called a stem cell. These are nature’s “master” cells, which can be “programmed” to regenerate a wide variety of cells and tissues.
Because stem cells can regenerate other types of body cells and tissues, stem cells have the ability to aid in healing. This is why scientists and doctors are so excited about the growing role of stem cells to treat disease, injury, and the deterioration of tissue due to aging. Amazingly, after our birth and into adulthood, we keep a store of these stem cells in certain parts of our body.
MESENCHYMAL STEM CELLS
Stem cells come in different forms. One of the most well understood and widely researched types of stem cells is the mesenchymal stem cell. This type of stem cell can be found in the healthy dental pulp of teeth.
Mesenchymal stem cells can form tissues such as tendons, muscles, and blood vessels.
YOUNGER IS BETTER
The younger the stem cell, the more potent the stem cell. Freezing cells in a youthful state preserves their future ability to generate replacement tissue and heal the body. Younger cells divide more frequently, grow faster, and can turn into a greater variety of cell types. Why do you think a seven year old heals so much faster than a seventy year old?
All of these attributes make stem cells the cornerstone of the emerging field of treatments and therapies called Regenerative Medicine.