Why does staying up late and sun accelerating skin aging?
Shanghai scientists uncover a new mechanism of skin epithelial tissue aging
News from our newspaper (Reporter Xu Qimin) After staying up all night, the skin condition will be very poor. Frequent wind and sun will make it look old. What is accelerating skin aging?
Is there a way to delay skin aging?
Recently, Shanghai scientists have not only found the "black hand" that accelerates skin aging, but also found a way to combat it.
Researcher Zhang Liang’s team from Shanghai Institute of Nutrition and Health, Chinese Academy of Sciences and Professor Li Qingfeng’s team from the Ninth People’s Hospital Affiliated to Shanghai Jiaotong University School of Medicine recently published an article on "Nature-Aging". They found through mouse model research and clinical sample analysis. A miR-31–CLOCK–ERK signaling pathway activated by genomic or physical damage is a key molecular mechanism driving the aging of skin epithelial tissues, and it has been discovered that the clinical anticancer drug trametinib may have potential new uses for anti-skin aging.
The skin has a strong regenerative ability, which can continuously regenerate hair and heal wounds.
This regenerative ability mainly comes from skin epithelial stem cells hidden in the epidermis and hair follicles.
But in the process of aging, these stem cells will gradually deplete, leading to thinning of the epidermis, slow wound healing, and thinning and whitening of hair.
Why do skin stem cells fail?
Scientists have discovered a stimulatory mechanism in skin stem cells, which is the root cause of their prone to a large number of external damage and stimulation.
The research team found that a small RNA called miR-31 in epithelial cells is a key role in urging skin hair follicle stem cells to stimulate.
No matter physical damage or damage such as sun/radiation, it will cause its content in the skin to rise rapidly.
Experiments in mice have shown that if it has a large number of cells and is active, hair follicle stem cells will easily pop out and quickly exhaust; once its gene is knocked out, hair follicle stem cells will become indifferent, and skin aging will follow. It slows down.
Interestingly, the research team found a large amount of miR-31 in aging human epidermis and hair follicles, which suggests that it is likely to act on the aging of human epidermis and hair follicles at the same time.
This stimulus mechanism can temporarily strengthen the skin's ability to resist external damage, which is naturally a good thing for animals to cope with the stress of survival in the wild.
"However, skin stem cells are not perpetual motion machines. They will be exhausted." Zhang Liang told reporters that in the process of skin aging, it is the constant stimulation that ultimately leads to the failure of skin stem cells.
Once the stem cells fail, skin aging phenomena such as baldness, gray hair, thinning of the epidermis, and slow wound healing will appear.
Moreover, the research team also found that miR-31 down-regulates the expression of its target gene CLOCK, thereby activating the classic MAPK/ERK signaling pathway, which in turn drives the transdifferentiation and depletion of hair follicle stem cells to the epidermis.
"CLOCK is a rhythm-related gene, which may explain why the skin becomes worse after staying up late, and it is easy to lose hair if staying up often, and a regular and healthy life can make the skin and hair healthier and moisturized." Zhang Liang said, this also Remind researchers that if a drug that blocks this miR-31–CLOCK–MAPK/ERK pathway can be found, it will not overdrive skin stem cells to work.
In fact, "In modern society, humans no longer need the powerful skin repair capabilities like wild animals. If skin stem cells can be calmed down and released slowly, then skin and hair can delay aging."
Soon, they discovered that the MAPK/ERK pathway inhibitors represented by the clinical anticancer drug trametinib can significantly antagonize the premature skin aging of mice caused by ionizing radiation, without obvious side effects, and are administered orally or on the skin. Both can take effect.
"The ionizing radiation used in tumor radiotherapy will also accelerate the aging of human skin, leading to intractable sequelae such as thinning of the epidermis, slow healing, and hair loss." Zhang Liang believes that the topical trametil developed by them in animal experiments Nicotine may benefit cancer patients undergoing radiotherapy and protect their skin.
"Perhaps, in the future, new skin care and hair care products can be developed based on such drugs to delay the natural aging of skin and hair and sun aging." He reminded the public that, from the perspective of the mechanism of skin and hair aging, through sun protection and skin cream application It is undoubtedly a good way to reduce the external irritation to the skin; staying up late and maintaining a regular schedule are also good natural "skin care products."