Shiseido’s probe into mechanisms of skin cell aging uncovers special protein responsible for senescence

14 Jun 2023 --- Shiseido has pinpointed the biological mechanisms of special proteins affecting the aging of skin cells, also referred to as the process of senescence. The Japanese beauty brand worked with US-based scientists at the Cutaneous Biology Research Center (CBRC) at Massachusetts General Hospital for a total of five years to understand this occurrence. 

The researchers discovered the influence of a specific protein called YBX1. When this protein is “phosphorylated” (modified by attaching phosphate groups), it leads to the aging of skin cells because this reduces its functions.

The scientists also found that preventing this phosphorylation increases the number of epidermal stem cells, which is important for maintaining healthy skin. This suggests that not only the quantity but also the “quality” and health of these epidermal stem cells are important for maintaining youthful skin.

“Skin turnover, which occurs as a result of cells in the epidermis constantly proliferating and differentiating, is important to maintain healthy skin,” Shiseido states. “Epidermal stem cells are the sources of these cells and are found in the deepest part of the epidermis called the basal layer.”

Ensuring healthy skin turnover
Shiseido presented the results of their research at a dermatology conference called the International Societies of Investigative Dermatology Meeting, which took place in Tokyo, Japan, last month.

But the research collaboration between CBRC and Shiseido is decades old and has been ongoing since 1989. Shiseido regularly sends its researchers to work alongside CBRC scientists.

“Shiseido has been engaged in epidermal stem cell research for ten years,” outlines the company.

The researchers discovered the influence of a specific protein called YBX1.“As a result, we have discovered that supporting the maintenance of epidermal stem cells through the basement membrane, which lies beneath the basal layer of the epidermis, contributes to the retention of skin moisture and barrier function, and even the production of collagen in the dermis.”

Can a drug reverse skin aging?
The team behind the new study, led by associate professor Anna Mandinova at CBRC, have previously published reports confirming that a decrease in the level of the YBX1 leads to the senescence of epidermal stem cells. They also found that this catalyst ages surrounding cells by secreting other types of proteins.

In the current study, the researchers revealed that phosphorylated YBX1 in many epidermal stem cells collected from donors of different ages indeed showed reduced function.

Moreover, when a drug that inhibits the phosphorylation of YBX1 was added to the cultured cells containing epidermal stem cells, the results indicated a “suppressing” effect of the drug on cellular senescence.

These effects were found to apply to both general aging of the skin and the influence of sunlight exposure. On the other hand, it was found that in comparison to the portion of the skin that was not exposed to sunlight (“sun-protected”), the part of the skin exposed to sunlight (“sun-exposed”) had a significantly increased level of phosphorylated YBX1.

“These results suggest that changes in the skin caused by exposure to sunlight over prolonged periods of time – i.e., photoaging – may be a factor contributing to YBX1 phosphorylation,” conclude the researchers.

Science of skin
In other novel research developments, Shiseido developed a technique to inhibit melanin production that combines Panax ginseng root extract – a popular botanical ingredient originating from East Asia – with unique radio frequency irradiation, based on high-frequency electrical stimulation at a uniquely set frequency.

The beauty giant also recently investigated the skin revitalizing properties in a trio of botanical active ingredients. Shiseido succeeded in reproducing a “thinning” phenomenon, which is characterized by a decreased thickness of the dermis caused by aging.

In January, Shiseido unveiled a “world’s first” measurement system that employs a non-invasive approach to visually and numerically analyze the 3D facial shape and optical properties of the skin to understand the factors involved with changes in skin appearance. 

Among other activities, the company has investigated the effects of yuzu fruit-based epidermal regeneration, as well as hyaluronic acid’s function in strengthening the healthy barrier function of lips.

By Benjamin Ferrer