Menard confirms protein that suppresses stem cell proliferation

 Nippon Menard Cosmetics, in collaboration with Fujita Medical University School of Medicine, is conducting research on the mechanism by which epidermal stem cells decrease due to aging. Found to suppress. It is speculated that this protein affects the ability of the skin to regenerate.

It is known that the epidermis, which constitutes the outermost part of the skin, becomes thinner and metabolism slows down with aging. Although it has been found that these changes are associated with a decrease in "epidermal stem cells" that produce epidermal stem cells, there are still many unclear points as to the cause of the decrease in epidermal stem cells.

Therefore, the joint research group focused on skin stem cells and continued research on the relationship with aging. This time, a protein called "activin βA (activin A)" increases with aging in the epidermis, and the proliferation of epidermal stem cells is promoted. Found to suppress. It was also confirmed that epidermal stem cells were actually decreased in the epidermis containing a large amount of activin βA (activin A), and that activin βA (activin A) thinned the epidermal tissue.

From the above results, it was considered important to suppress the amount of activin βA (activin A), which increases with aging, in order to maintain the health and youthfulness of the skin. In the future, we will proceed with further analysis and develop a technology to control activin βA (activin A) in the skin.

It is becoming known that aged cells secrete various proteins that reduce their functions to the surrounding tissues and cells. This time, we focused on a protein called activin βA (activin A) among the proteins secreted by aged cells, and examined how it is involved in epidermal aging.

As a result of analyzing the skin tissues of young people (8-37 years old, 21 people in total) and elderly people (61-77 years old, 21 people in total), activin βA (activin A) increased in the entire epidermis with aging. I found out that. It was also observed that the epidermis containing a large amount of activin βA (activin A) had a thin tissue and was thinned. From the above results, activin βA (activin A) was considered to be involved in epidermal aging.

In order to analyze in detail how activin βA (activin A) is involved in epidermis aging, the amount of activin βA (activin A) in the epidermis of elderly people (60-77 years old, 15 people in total), The number of epidermal stem cells and the number of proliferating cells in the basal layer were investigated. As a result, it was found that the number of epidermal stem cells and proliferating cells was small in the epidermis having a large amount of activin βA (activin A).

From this result, it was considered that activin βA (activin A) is involved in the decrease of epidermal stem cells and the suppression of the proliferation of cells in the basal layer.

In order to verify the action of activin βA (activin A) on epidermal stem cells, activin βA (activin A) was added to the culture medium of epidermal stem cells and cultured. As a result, as the amount of activin βA (activin A) added increased, the proliferation of epidermal stem cells was suppressed. In other words, it was found that activin βA (activin A) has an effect of suppressing the proliferation of epidermal stem cells.

In order to evaluate the effect of activin βA (activin A) on the structure of the epidermis, inhibin βA (activin A) was added to a three-dimensional cultured epidermal model using epidermal stem cells and cultured, and the state of the epidermis was analyzed. As a result, the epidermis model with the addition of activin βA (activin A) had a thinner tissue than the epidermis model without the addition. A detailed analysis of this epidermal model revealed that the addition of activin βA (activin A) reduced the number of proliferating cells in the basal region. From the above results, it was considered that suppression of epidermal stem cell proliferation by activin βA (activin A) leads to skin thinning.

According to this study, inhibin βA (activin A) is thought to thin the epidermal tissue by suppressing the proliferation of epidermal stem cells. Therefore, it is possible to suppress the increase in inhibin βA (activin A) with aging. If this is possible, it is expected to lead to the maintenance of epidermal stem cells and the prevention of epidermal aging.