Fig. 1.

Sphingolipid rheostat in atopic dermatitis. Keratinocytes produce sphingolipids via the de novo pathway from palmitoyl-CoA and serine in the form of glucocerebrosides and sphingomyelin. These are secreted into the stratum corneum where they are transformed into ceramides and are available for the skin barrier. In atopic dermatitis the increased activity of the two enzymes glucosylceramide and sphingomyelin-deacylase result in reduced ceramide levels and in a disturbance of the epidermal barrier. An increased S1P lyase activity is also discussed, so that S1P concentrations are reduced leading to a reduction in function as a biological signaling molecule.

© B. Kleuser