S100 Proteins in the Pathogenesis of Psoriasis and Atopic Dermatitis.

The skin, the outermost layer of the human body, is exposed to various external stimuli that cause inflammatory skin reactions. These external stimulants trigger external epithelial cell damage and the release of intracellular substances. Following cellular damage or death, intracellular molecules are released that enhance tissue inflammation. As an important substance released from damaged cells, the S100 protein is a low-molecular-weight acidic protein with two calcium-binding sites and EF-hand motif domains. S100 proteins are widely present in systemic organs and interact with other proteins. Recent studies revealed the involvement of S100 in cutaneous inflammatory disorders, psoriasis, and atopic dermatitis. This review provides detailed information on the interactions among various S100 proteins in inflammatory diseases.