New Thoughts on Aging

Inducing stem cell production from reservoirs and expanding them into the aged dermal layer may inhibit age-related changes in the skin, according to recent findings by Shiseido. Senescent cells,which are created in the skin with aging, are associated with deterioration in the functions of surrounding normal cells and cause aging-related changes in the skin. But in a joint research project conducted with Kyoichi Matsuzaki, senior professor of the Plastic and Reconstructive Surgery Department at the International University of Health and Welfare School of Medicine, and with the National Institute for Physiological Sciences, the research team identified that dermal stem cells suppress the “propagation of aging” and such stem cells, which drastically decrease with aging, are well maintained around the sebaceous glands even in aged skin. Furthermore, the team also discovered that iris extract attracts stem cells.


These research results are expected to be a critical solution for skin rejuvenation with the utilization of stem cells, and Shiseido will apply these new findings to future product development. The results of this research were partly introduced at the Podium Presentation of the 30th IFSCC Congress 2018 held in Munich, Germany and won the Congress Award.

Age-related facial wrinkles and sagging skin are major skin concerns among consumers. These changes in superficial morphology are chiefly caused by the degradation of the dermal layer with aging; however, the exact mechanism had not been identified, according to Shiseido. During this joint research, the team newly developed a technology for electron microscopy analysis and succeeded in observing even minute changes in cell shape. Analysis of the dermal layer with this technology showed that the dermal cells (fibroblasts) of young subjects have several dendrites whereas the cells from aged subjects lose dendrites and change in shape. The results of the experiment with fibroblasts indicated that aged cells have a negative influence on surrounding skin cells as they release an aging factor, and it is clarified that age-related changes in the dermal layer are induced by this “propagation of aging.”

 

While searching for methods to inhibit the propagation of aging, the team discovered that dermal stem cells suppress the generation of aging factor from aged cells. Dermal stem cells (with a positive expression of stem cell markers), while significantly reduced with aging, are well maintained around nearby sebaceous glands even in aged skin. With these findings, it is identified that sebaceous glands act as a “reservoir,” storing stem cells in the nearby area. These lines of findings suggest that by inducing the generation of stem cells from reservoirs and expanding them into the aged dermal layer, the propagation of aging can be inhibited, and the dermal layer may be maintained in good condition. Moreover, by further pursuing research with stem cells, the team discovered that the extract of irises attracts stem cells.