Abnormalities in stratum corneum structure, lipid composition, and desmosome degradation in soap-induced winter xerosis

Abstract

in the lower stratum comeurn but underwent degradation towards the upper surface of the stratum corneum. These observations contrasted with xerotic skin, which had disorganized lipid bilayers in the upper stratum corneum, although apparently normal lipid bilayers in the deeper tissue regions. Also, desmosomes remained undegraded in the upper layers of the xerotic stratum corneum, a finding corroborated by western blotting showing increased levels of desmoglein 1. Chromatographic analysis of stratum comeurn lipids showed decreased ceramide and increased fatty acid levels in subjects with xerosis compared with normal individuals, particularly in the outer stratum corneum layers. Although ceramides were lost from the stratum comeurn, the increased levels of fatty acids may be due in part to the deposition of soap fatty acids. Our results support previous studies demonstrating the importance of desmosomal degradation in desquamation. Furthermore, we have been able to show changes in the normal membrane structure of intracellular lipids in the desquamating layers of the stratum comeurn. These studies also provide new insights into soap-induced winter xerosis, revealing abnormalities in stratum comeurn lipid composition and organization together with reduced desmosomal degradation.