A research group led by Assistant Professor Hiroyuki Matsumura, Specially Appointed Assistant Professor Yasuaki Mouri, and Professor Emi Nishimura of Tokyo Medical and Dental University, Institute for Intractable Diseases, and Stem Cell Medicine has elucidated the mechanism of age-related thinning and hair loss.
With aging, the organs in the human body become smaller and smaller and less functional.The skin becomes thinner and the hair becomes thinner and less.Regarding the mechanism of aging, research using nematodes, cultured cells, aging model mice, etc. has been active for a long time, but the changes actually occurring in the living body are unknown, and there is a program for aging at the tissue and organ level. It was not clear if it existed.
In this study, we focused on the fact that hair follicles, which are small organs that grow hair, construct a stem cell system with stem cells at the apex, and that thinning hair is also seen with aging in mice. The fate of the hair was tracked in vivo for a long period of time and analyzed together with the age-related changes in the human scalp.Accumulation of DNA damage in hair follicle stem cells with aging causes the degradation of type XVII collagen, an important molecule in the maintenance of hair follicle stem cells.It was shown for the first time that the hair follicle stem cells differentiated into epidermal keratinocytes and fell off from the skin surface together with dandruff and dirt, and the hair follicles became smaller and disappeared.Furthermore, it was found that suppressing the depletion of type XVII collagen in mouse hair follicle stem cells can suppress a series of dynamic age-related changes.
From these facts, it is clarified for the first time that the human body has an "aging program centered on stem cells" in tissues and organs, and its control is useful for the prevention and treatment of various age-related diseases. Was suggested.It is expected to give a new perspective on the mechanism of aging and at the same time lead to the development of treatments for alopecia and the treatment of other age-related diseases.