Order and disorder in corneocyte adhesion (角質細胞接着における正常と疾患)

AuthorEpidermal cornified cells are attached to each other with modified desmosomes, namely corneodesmosomes. Changes in corneodesmosome degradation process influence the total thickness of stratum corneum and the surface appearance of the skin. The major extracellular constituents of corneodesmosomes are desmoglein 1, desmocollin 1 and corneodesmosin. The intracellular part of corneodesmosomes is cross-linked into cornified cell envelopes. Corneodesmosomes are degraded from the central surface area of each cell. Peripheral corneodesmosomes retain structural integrity up to the skin surface. A hypothesis where tight junctions in the stratum corneum play a role in this spatial difference in corneodesmosome degradation has recently been proposed. Genetic defects in corneodesmosin and inhibitors for proteases involved in corneodesmosome degradation result in accelerated desquamation and severe barrier impairment, presenting as the inflammatory type of peeling skin syndrome and Netherton syndrome, respectively. Abnormal corneodesmosome degradation is also found in more common skin diseases including ichthyosis vulgaris, atopic dermatitis, psoriasis vulgaris, lichen planus and soap-induced xerosis