The role of ceramides in skin homeostasis and inflammatory skin diseases

Ceramides, members of sphingolipid family, are not only the building blocks of epidermal barrier structure, but also bioactive metabolites involved in epidermal self-renewal and immune regulation. Hence, abnormal ceramide expression profile is recognized to defect extracellular lipid organization, disturb epidermal self-renewal, exacerbate skin immune response and actively participate in progression of several inflammatory dermatoses, exemplifying by psoriasis and atopic dermatitis. Here, we discuss recent advances in understanding skin ceramides and their regulatory roles in skin homeostasis and pathogenic roles of altered ceramide metabolism in inflammatory skin diseases. These insights provide new opportunities for therapeutic intervention in inflammatory dermatoses. (C) 2019 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights reserved.