1. ¹Division of Signal Transduction and Growth Control, Deutsches Krebsforschungszentrum, Heidelberg, Germany
2. ²Department of Dermatology and Venerology, University of Cologne, Cologne, Germany

Correspondence: Professor Peter Angel, Division of Signal Transduction and Growth Control, Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany. E-mail: p.angel@dkfz.de

Received 20 April 2005; Revised 24 October 2005; Accepted 31 October 2005; Published online 26 January 2006.

Abstract

The cutaneous response to injury and stress comprises a temporary change in the balance between epidermal proliferation and differentiation as well as an activation of the immune system. Soluble factors play an important role in the regulation of these complex processes by coordinating the intercellular communication between keratinocytes, fibroblasts, and inflammatory cells. In this study, we demonstrate that JunB, a member of the activator protein-1 transcription factor family, is an important regulator of cytokine expression and thus critically involved in the cutaneous response to injury and stress. Mice lacking JunB in the skin develop normally, indicating that JunB is neither required for cutaneous organogenesis, nor homeostasis. However, upon wounding and treatment with the phorbol ester 12-O-decanoyl-phorbol-13-acetate, JunB-deficiency in the skin likewise resulted in pronounced epidermal hyperproliferation, disturbed differentiation, and prolonged inflammation. Furthermore, delayed tissue remodelling was observed during wound healing. These phenotypic skin abnormalities were associated with JunB-dependent alterations in expression levels and kinetics of important mediators of wound repair, such as granulocyte macrophage colony-stimulating factor, growth-regulated protein-1, macrophage inflammatory protein-2, and lipocalin-2 in both the dermal and epidermal compartment of the skin, and a reduced ability of wound contraction of mutant dermal fibroblasts in vitro.