RESUMO
Ex vivo culture of mouse and human skin causes an inflammatory response characterized by production of multiple cytokines. We used ex vivo culture of mouse tail skin specimens to investigate mechanisms of this skin culture-induced inflammatory response. Multiplex assays revealed production of interleukin 1 alpha (IL-1α), interleukin 1 beta (IL-1ß), interleukin 6 (IL-6), chemokine C-X-C motif ligand 1 (CXCL1), granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) during skin culture, and quantitative PCR revealed transcripts for these proteins were also increased. Ex vivo cultures of skin from myeloid differentiation primary response 88 deficient mice (Myd88-/- ) demonstrated significantly reduced expression of transcripts for the aforementioned cytokines. The same result was observed with skin from interleukin 1 receptor type 1 deficient mice (Il1r1-/- ). These data suggested the IL-1R1/MyD88 axis is required for the skin culture-induced inflammatory response and led us to investigate the role of IL-1α and IL-1ß (the ligands for IL-1R1) in this process. Addition of IL-1α neutralizing antibody to skin cultures significantly reduced expression of Cxcl1, Il6 and Csf3. IL-1ß neutralization did not reduce levels of these transcripts. These studies suggest that IL-1α promotes the skin the culture-induced inflammatory response.
Assuntos
Inflamação/genética , Interleucina-1alfa/genética , Pele/fisiopatologia , Animais , Anticorpos Neutralizantes/farmacologia , Quimiocina CXCL1/genética , Quimiocina CXCL1/metabolismo , Inflamação/metabolismo , Inflamação/patologia , Interleucina-1alfa/antagonistas & inibidores , Interleucina-1alfa/metabolismo , Interleucina-1beta/antagonistas & inibidores , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Interleucina-6/genética , Interleucina-6/metabolismo , Camundongos , Camundongos Knockout , Fator 88 de Diferenciação Mieloide/genética , Pele/patologia , Técnicas de Cultura de TecidosRESUMO
The Stat6VT mouse model of atopic dermatitis (AD) is induced by T-cell-specific expression of a constitutively active form of the protein signal transducer and activator of transcription 6 (STAT6). Although AD-like lesions are known to develop in Stat6VT mice, this study was designed to determine if these mice develop acute and chronic phases of disease similar to humans. To address this, AD-like lesions from Stat6VT mice were harvested at two different timepoints relative to their onset. Lesions harvested within 1 week after development were defined as acute lesions, and those present for 1 month or more were defined as chronic lesions. Acute and chronic AD-like lesions from Stat6VT mice exhibited histologic findings and cytokine expression patterns similar to acute and chronic AD lesions in humans. Further analysis revealed increased levels of interleukin (IL)-33 transcripts in AD-like lesions compared to Stat6VT nonlesional and wild-type skin controls. Immunofluorescence also revealed increased numbers of IL-33+ keratinocytes in Stat6VT lesional skin and localized IL-33+ keratinocytes to a keratin 5+ subset. Furthermore, AD-like disease was more severe in IL-33-deficient Stat6VT mice compared to IL-33-sufficient Stat6VT mice. These studies suggest that Stat6VT mice can serve as a model of acute and chronic AD and that IL-33 may attenuate inflammation in this system.