Fig. 8

Model of congenital ichthyosis related to the barrier change in epidermis layers. The stratum corneum (SC) is the outermost layer of the epidermal barrier. The corneocytes of the SC act as bricks that form a hydrophilic wall that is surrounded by a lipophilic ‘‘mortar’’ made up of lipid lamellae, which fill the extracellular space. Genomics defects underlying CI diseases alter the epidermal barrier at various levels (SC, stratum spinosum (SS), and stratum basale (SB)), enabling pathogenic microorganisms to proliferate, invade, and cause microbial dysbiosis in the skin. In CI patients, as shown in this study, microbial dysbiosis and/or skin wounding amplifies Th17-driven inflammation in the skin, which can be associated with elevated JAK/STAT signaling