Suprabasal integrin expression in the epidermis of transgenic mice results in developmental defects and a phenotype resembling psoriasis

AbstractIntegrin expression is normally confined to the basal layer of the epidermis, but when epidermal homeostasis is perturbed, the receptors are also expressed by suprabasal, differentiating keratinocytes. We have used the involucrin promoter to express functional human integrin subunits α2, α5, and β1 in the suprabasal epidermal layers of transgenic mice. In mice expressing α5 or β1 alone or α2β1 or α5β1, heterodimers, there were hair and whisker abnormalities and a failure of eyelid fusion. In addition, mice expressing β1 alone or in combination with α2 or α5 exhibited epidermal hyperproliferation, perturbed keratinocyte differentiation, and skin inflammation, all of which are features of a common human skin disease, psoriasis