Abstract Body: Skin is the largest organ of the body and the more exposed to free radicals produced by cellular metabolism, stress and present in our external environment. Consequently, those free radicals induce a premature skin aging and an increase of the risk of skin cancer. Supplementation with anti-oxidant molecules is effective to reduce the effect of oxidative stress. Among antioxidants, selenoproteins play a key role in antioxidant defense and in maintaining a reduced cellular environment. Selenium, essential for their activity, is an essential trace element that must be provided by diet or supplementation. Few studies have focused on the protective role of selenium against chronological skin aging and/or photoaging even though selenoproteins are essential for keratinocyte function and skin development.
Here, our work aim to study the role of selenium in skin homeostasis and aging.
We demonstrate a role of selenium on replicative life span of primary keratinocytes and on chronological aging of skin. A low dose of selenium is effective on maintaining clonogenic potential over replicative life span. Selenium protects keratinocyte stem cells against senescence via preservation of their stemness phenotype through adhesion to the basement membrane. Additionally, using an extended-live culture skin model mimicking chronological aging, our results shows that selenium supplementation maintains the homeostasis of skin during chronological aging. Controlled supplementation with Selenium could be a new strategy to protect skin against aging.

Selenium preserves keratinocyte stemness and delays senescence by maintaining epidermal adhesion