1. Research Institute of Molecular Pathology, Dr. Bohr-Gasse 7, A-1030 Vienna, Austria
2. Division of Signal Transduction and Growth Control and
3. Division of Molcular Genetics, Deutsches Krebsforschungszentrum, D-69120 Heidelberg, Germany
4. Department of Dermatology, Medical University of Vienna, A-1090 Vienna, Austria
5. Centre de Recherches et d'Investigations Épidermiques et Sensorielles, F-9251 Neuilly, France

Correspondence to: Erwin F. Wagner¹ Correspondence and requests for materials should be addressed to E.F.W. (Email: wagner@imp.univie.ac.at).

Abstract

Psoriasis is a frequent, inflammatory disease of skin and joints with considerable morbidity. Here we report that in psoriatic lesions, epidermal keratinocytes have decreased expression of JunB, a gene localized in the psoriasis susceptibility region PSORS6. Likewise, inducible epidermal deletion of JunB and its functional companion c-Jun in adult mice leads (within two weeks) to a phenotype resembling the histological and molecular hallmarks of psoriasis, including arthritic lesions. In contrast to the skin phenotype, the development of arthritic lesions requires T and B cells and signalling through tumour necrosis factor receptor 1 (TNFR1). Prior to the disease onset, two chemotactic proteins (S100A8 and S100A9) previously mapped to the psoriasis susceptibility region PSORS4, are strongly induced in mutant keratinocytes in vivo and in vitro. We propose that the abrogation of JunB/activator protein 1 (AP-1) in keratinocytes triggers chemokine/cytokine expression, which recruits neutrophils and macrophages to the epidermis thereby contributing to the phenotypic changes observed in psoriasis. Thus, these data support the hypothesis that epidermal alterations are sufficient to initiate both skin lesions and arthritis in psoriasis.

MORE ARTICLES LIKE THIS

These links to content published by NPG are automatically generated.