We have updated our privacy policy. If you have any question, contact us at privacy@scicrunch.org. Dismiss and don't show again

Searching across hundreds of databases

Our searching services are busy right now. Your search will reload in five seconds.

Forgot Password

If you have forgotten your password you can enter your email here and get a temporary password sent to your email.

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

In prostanoid biosynthesis, the first two steps are catalyzed by cyclooxygenases (COX). In mice and humans, deregulated expression of COX-2, but not of COX-1, is characteristic of epithelial tumors, including squamous cell carcinomas of skin. To explore the function of COX-2 in epidermis, a keratin 5 promoter was used to direct COX-2 expression to the basal cells of interfollicular epidermis and the pilosebaceous appendage of transgenic mouse skin. COX-2 overexpression in the expected locations, resulting in increased prostaglandin levels in epidermis and plasma, correlated with a pronounced skin phenotype. Heterozygous transgenic mice exhibited a reduced hair follicle density. Moreover, postnatally hair follicle morphogenesis and thinning of interfollicular dorsal epidermis were delayed. Adult transgenics showed a body-site-dependent sparse coat of greasy hair, the latter caused by sebaceous gland hyperplasia and increased epicutaneous sebum levels. In tail skin, hyperplasia of scale epidermis reflecting an increased number of viable and cornified cell layers was observed. Hyperplasia was a result of a disturbed program of epidermal differentiation rather than an increased proliferation rate, as reflected by the strong suppression of keratin 10, involucrin, and loricrin expression in suprabasal cells. Further pathological signs were loss of cell polarity, mainly of basal keratinocytes, epidermal invaginations into the dermis, and formation of horn perls. Invaginating hyperplastic lobes were surrounded by CD31-positive vessels. These results demonstrate a causal relationship between transgenic COX-2 expression in basal keratinocytes and epidermal hyperplasia as well as dysplastic features at discrete body sites.

Pubmed ID: 11381142 RIS Download

Mesh terms: Aging | Animals | Cattle | Cell Differentiation | Cell Division | Cyclooxygenase 2 | Epidermis | Hair | Hair Follicle | Heterozygote | Hyperplasia | Isoenzymes | Keratins | Membrane Proteins | Mice | Mice, Transgenic | Phenotype | Promoter Regions, Genetic | Prostaglandin-Endoperoxide Synthases | Prostaglandins | Protein Precursors | Reverse Transcriptase Polymerase Chain Reaction | Sebaceous Glands | Skin

Research resources used in this publication

None found

Research tools detected in this publication

None found

Data used in this publication

None found

Associated grants


Mouse Genome Informatics (Data, Gene Annotation)

Publication data is provided by the National Library of Medicine ® and PubMed ®. Data is retrieved from PubMed ® on a weekly schedule. For terms and conditions see the National Library of Medicine Terms and Conditions.

We have not found any resources mentioned in this publication.