Discovery that "Beige Fat Cells" that Burn Energy Enhance Skin Barrier Function

KOSÉ Corporation (Head Office: Chuo-ku, Tokyo; President and Representative Director: Shinji Tanaka) and DIVA Expertise (Head Office: Toulouse, France; CEO: Mayoura Kéophiphath), a bio-venture company, have jointly revealed that fat cells in the deep layers of the skin, when differentiated into "beige fat cells" that burn energy, lead to improved skin barrier function, which is essential for healthy skin. A portion of these research findings was presented at the 26th Annual Meeting of the Japanese Society for Anti-Aging Medicine (June 2026).

Figure 1: Influence of Fat Cells on the Epidermis

Background of the Research

It is widely known that lifestyle habits affect skin and beauty. The skin has a layered structure consisting of the epidermis, dermis, and subcutaneous tissue. Fat cells, which constitute the majority of subcutaneous tissue, exist in two types: "white fat cells" that store energy and "beige fat cells" that burn energy. These fat cells change from white to beige with moderate exercise and a healthy diet, and from beige to white with lack of exercise and excessive calorie intake. While these two types of fat cells reversibly change depending on lifestyle habits, the specific differences in their effects on the skin had not yet been elucidated. Therefore, this research focused on the "browning" of fat cells, which is deeply related to lifestyle habits, and aimed to clarify the effects of fat cells on the skin.

Discovery that Beige Fat Cells Improve Epidermal Barrier Function

To verify the effects of the secretions from the two types of fat cells on skin tissue, joint research was conducted by our company's research laboratory, Lyon Branch (France), which possesses human skin culture evaluation technology, and DIVA Expertise, which has high expertise in fat cell culture and evaluation. As a result of co-culturing human skin with either white fat cells or beige fat cells, it was found that beige fat cells increased filaggrin (FLG), a factor important for maintaining the moisturizing barrier function of the epidermis, compared to white fat cells. Furthermore, it was suggested that the indicator of "endoplasmic reticulum stress," which leads to a decrease in epidermal barrier function, BiP, was reduced (Figure 1).

Figure 2: Gene expression levels of epidermal cells treated with fat cell secretions

Furthermore, this phenomenon was also examined in terms of gene expression, which provides the instructions for producing each factor. When the secretions from each type of fat cell were added to epidermal cells and analyzed, it was confirmed that beige fat cells reduced the expression levels of endoplasmic reticulum stress-related genes such as HSPA5 and PPP1R15A compared to white fat cells. It was also confirmed that the expression levels of genes important for maintaining epidermal barrier function, such as FLG and CASP14, were increased (Figure 2).

Based on the above results, it was suggested that promoting the "browning" of white fat cells can alleviate endoplasmic reticulum stress in the epidermis and lead to improved skin barrier function.

Future Prospects

This research suggests the possibility that the "browning" of fat cells contributes to the improvement of skin barrier function. This finding is expected to be applied not only to skincare products but also to proposals for total beauty, including improvements in exercise and dietary habits. In the future, we will further elucidate the relationship between adipose tissue and skin, and aim to provide new products and services that cater to all of our customers' skin concerns and contribute to the improvement of their QOL.