title: Induction of inflammatory cytokines by a keratin mutation and their repression by a small molecule in a mouse model for EBS.
abstract: Epidermolysis bullosa simplex (EBS) is a skin disorder caused by mutations in keratin (K) 5 or K14 genes. It is widely regarded as a mechanobullous disease, resulting from a weakened cytoskeleton, causing extensive cytolysis. It was postulated by others that certain K14 mutations induce tumor necrosis factor-alpha (TNF-alpha) and increase apoptosis. Here, we report that in K5-/- mice and in a cell culture model of EBS, the mRNA and protein levels of TNF-alpha remain unaltered. Transcriptome analysis of K5-/- mice revealed, however, that the proinflammatory cytokines IL-6 and IL-1beta were significantly upregulated at the mRNA level in K5-/- mouse skin. These results were confirmed by TaqMan real-time PCR and ELISA assays. We hypothesize that keratin mutations contribute to EBS in a mouse model by inducing local inflammation that mediates a stress response. Following clinical reports, we applied the small molecule doxycycline to K5-/- mice. We demonstrate that doxycycline extended the survival of neonatal K5-/- mice from less than 1 to up to 8 hours. Microarray and TaqMan real-time PCR showed a downregulation of matrix metalloproteinase 13 and IL-1beta, indicating an effect of doxycycline on transcription. Our data offer a novel small molecule-based therapy approach for EBS.
authors.affiliation: Institut für Physiologische Chemie, Abteilung für Zellbiochemie, Bonner Forum Biomedizin and LIMES, Rheinische Friedrich-Wilhelms-Universität, Nussallee 11, Bonn, Germany.
authors.forename: Hong
authors.initials: H
authors.lastname: Lu
authors.forename: Jian
authors.initials: J
authors.lastname: Chen
authors.forename: Laura
authors.initials: L
authors.lastname: Planko
authors.forename: Paola
authors.initials: P
authors.lastname: Zigrino
authors.forename: Ludger
authors.initials: L
authors.lastname: Klein-Hitpass
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Magin
mesh_terms: D000818:Animals; D016207:Cytokines / Q000378:metabolism*; D004195:Disease Models, Animal; D004318:Doxycycline / Q000494:pharmacology; D016110:Epidermolysis Bullosa Simplex / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D007249:Inflammation; D053583:Interleukin-1beta / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D053555:Keratin-5 / Q000235:genetics* / Q000502:physiology; D053509:Matrix Metalloproteinase 13 / Q000378:metabolism; D051379:Mice; D009154:Mutation; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic
chemical_list: D016207:Cytokines; D053583:Interleukin-1beta; D015850:Interleukin-6; D053555:Keratin-5; D053509:Matrix Metalloproteinase 13; D004318:Doxycycline