Having thick hair is a good wish for many people, and thinning hair has become an unspeakable pain for many people. Studies have shown that 30%-50% of men will begin to experience seborrheic alopecia at the age of 50. The British “New Scientist” website recently reported that the science of curing hair loss is rapidly developing, including hair transplantation, “hair follicle banks” and anti-baldness vaccines.
There are many causes of hair loss
There are many different reasons why people lose hair. People may start losing their hair suddenly due to an infection or after chemotherapy; they may also lose their hair due to an autoimmune disease; but the most common is androgenic alopecia, which is characterized by a gradual thinning of hair on the upper or crown part of the forehead, although Men are mostly affected, but androgenic alopecia, which causes a receding hairline, is also common in women.
It is known that androgenic alopecia in men is related to male sex hormones, but the exact trigger is not known. Female androgenic alopecia, also thought to be caused by sex hormones, causes hair to become thinner but rarely progresses to complete baldness. For these people, the reason why their hair falls out more and grows less is related to the fact that the hair follicles are in the resting phase for a long time. Hair follicles in the scalp normally cycle through three stages: growth, involution and telogen. When the hair follicles enter the resting phase early, the hair falls out faster; if the hair follicles do not re-enter the growth phase, new hair will no longer start to grow.
Throughout the ages, people have been actively searching for various treatments for hair loss. The ancient Egyptians tried to rub ground donkey hooves, hippopotamus fat, etc. into their hair to suppress baldness; ancient Chinese also used ginger slices to rub their scalp; modern people use a variety of methods: scalp rollers, caffeine shampoo, Laser combs, microneedling, even rosemary oil, and more. Despite their unique strategies, there is little scientific evidence that these methods can slow or reverse hair loss.
In the past few years, researchers have made breakthroughs in understanding the biological mechanisms of hair growth and loss and finding treatments.
About 10 years ago, a team led by Harvard University cell biologist Carl Koehler tried to use stem cells to grow a type of cell found in the inner ear, and found that extra patches of skin always appeared. The team initially dismissed them as impurities, but later realized that if these skin fragments continued to grow, they would form the dermis and epidermis layers, and even form hair follicles.
So they pivoted and started growing stem cells into a patch of hair-bearing skin. It takes about 50-70 days to complete this process, and the resulting epidermis is spherical, about 4 mm wide. When the skin was transplanted onto the backs of mice, hair began to grow. Kohler said the studies could help test drugs to treat skin diseases and could potentially be a way to transplant hair onto bald heads.
Of course, hair transplants already exist, but they also have drawbacks. Follicular unit extraction (FUE), for example, extracts hair follicles from the sides and back of the head where hair is still growing and transplants them to areas of hair loss. The problem with FUE, besides the cost, is that it only redistributes hair and does not allow thicker hair to grow back on an empty scalp.
“Hair Follicle Bank”
There is a group of dermal papilla cells at the root of each hair, which are involved in regulating hair growth. And some of these key cells in the hair follicles are lost or even disappear altogether. The signal directing hair growth stops, and the hair becomes less. Why not replace dermal papilla cells?
Colin Jehoda of Durham University in the UK extracted these cells from mouse hair and injected them into the rodents’ ear skin. He found that the ear hair quickly grew longer.
In the early 2000s, regenerative medicine entrepreneur Paul Kemp studied whether injecting dermal papilla cells into the human scalp could stimulate the growth of new hair and found that the method worked. In 2015, Kemp founded HairClone and resumed research on dermal papilla cells. First, the research team extracted healthy dermal papilla cells from young people and froze them in a hair follicle bank. When these people’s scalps began to thin, the cells were cultured and injected back into the scalp. Based on this, HairClone created a “hair follicle bank” where people can extract some hair papilla cells and freeze them in the “bank”. This service has now entered the United States, Canada, Australia and the United Kingdom.
Each round of cloning reduces the ability of papilla cells to induce hair growth, which can be a challenge, notes Maria Kasper, who studies skin and hair biology at the Karolinska Institute in Stockholm, Sweden. But when the method works, it can be a long-term solution, and rejuvenated hair may last for decades.
In June last year, a team from the University of California, Irvine, published a paper in the journal Developmental Cells, revealing a key signaling molecule that can activate hair growth – SCUBE3 protein, providing a therapeutic target for the treatment of androgenic alopecia. .
The research team injected trace amounts of SCUBE3 protein into the skin of mice transplanted with human scalp hair follicles. The results showed that both the dormant human hair follicles and the surrounding mouse hair follicles in the mice grew hair again. This means that only microinjections of SCUBE3 protein are needed to activate hair growth in human hair follicles.
The researchers pointed out that the SCUBE3 protein could work like a new coronavirus vaccine by injecting it into the scalp or using it as an mRNA therapy.
In June this year, the team continued their efforts and published a research report in the journal Nature that a molecule called osteopontin was related to faster hair growth. The research team found that osteopontin interacts with the transmembrane adhesion glycoprotein CD44 in nearby hair follicle stem cells, which can activate hair follicle stem cells and lead to vigorous hair growth. Both injections of osteopontin and overexpression of osteopontin-related genes were sufficient to promote hair growth in mice.
In addition to osteopontin and CD44, the team is also studying the ability of other molecules present in hairy skin nevi to induce hair growth, hoping to find more molecules with activating effects.