Abnormal differentiation of epidermis in transgenic mice constitutively expressing cyclooxygenase-2 in skin

The study investigated the effects of COX-2 overexpression in the skin of transgenic mice, revealing that it led to increased prostaglandin levels and a pronounced skin phenotype. This included reduced hair follicle density, delayed hair follicle morphogenesis, and thinning of the interfollicular epidermis. Adult mice exhibited a sparse, greasy hair coat due to sebaceous gland hyperplasia and increased sebum levels. Additionally, hyperplasia of the scale epidermis in tail skin was observed, attributed to abnormal epidermal differentiation rather than increased cell proliferation. The study highlighted a causal link between COX-2 expression in basal keratinocytes and epidermal hyperplasia, along with dysplastic features at specific body sites.