RESUMEN
Ultraviolet (UV) wavelengths in sunlight are the prime cause of skin cancer in humans with both the UVA and UVB wavebands making a contribution to photocarcinogenesis. UV has many different biological effects on the skin that contribute to carcinogenesis, including suppression of adaptive immunity, sunburn and altering the migration of mast cells into and away from irradiated skin. Many molecular mechanisms have been identified as contributing to skin responses to UV. Recently, using gene set enrichment analysis of microarray data, we identified the alternative complement pathway with a central role for factor B (fB) in UVA-induced immunosuppression. In the current study we used mice genetically deficient in fB (fB-/- mice) to study the functional role of the alternative complement pathway in skin responses to UV. We found that fB is required for not only UVA but also UVB-induced immunosuppression and solar-simulated UV induction of the oedemal component of sunburn. Factor B-/- mice had a larger number of resident skin mast cells than control mice, but unlike the controls did not respond to UV by increasing mast cell infiltration into the skin. This study provides evidence for a function role for fB in skin responses to UV radiation. Factor B regulates UVA and UVB induced immunosuppression, UV induced oedema and mast cell infiltration into the skin. The alternative complement pathway is therefore an important regulator of skin responses to UV.
Asunto(s)
Factor B del Complemento/metabolismo , Edema/fisiopatología , Hipersensibilidad Tardía/fisiopatología , Mastocitos/efectos de la radiación , Piel/efectos de la radiación , Rayos Ultravioleta/efectos adversos , Animales , Movimiento Celular/fisiología , Movimiento Celular/efectos de la radiación , Factor B del Complemento/genética , Modelos Animales de Enfermedad , Edema/etiología , Femenino , Hipersensibilidad Tardía/etiología , Masculino , Mastocitos/fisiología , Ratones Endogámicos C57BL , Ratones Noqueados , Piel/fisiopatología , Quemadura Solar/etiología , Quemadura Solar/fisiopatologíaRESUMEN
One way sunlight causes skin cancer is by suppressing anti-tumor immunity. A major mechanism involves altering mast cell migration via the C-X-C motif chemokine receptor 4-C-X-C motif chemokine ligand 12 (CXCR4-CXCL12) chemokine pathway. We have discovered that pharmacologically blocking this pathway with the CXCR4 antagonist AMD3100 prevents both UV radiation-induced immune suppression and skin cancer. The majority of control mice receiving UV-only developed histopathologically confirmed squamous cell carcinomas. In contrast, skin tumor incidence and burden was significantly lower in AMD3100-treated mice. Perhaps most striking was that AMD3100 completely prevented the outgrowth of latent tumors that occurred once UV irradiation ceased. AMD3100 protection from UV immunosuppression and skin cancer was associated with reduced mast cell infiltration into the skin, draining lymph nodes, and the tumor itself. Thus a major target of CXCR4 antagonism was the mast cell. Our results indicate that interfering with UV-induced CXCL12 by antagonizing CXCR4 significantly inhibits skin tumor development by blocking UV-induced effects on mast cells. Hence, the CXCR4-CXCL12 chemokine pathway is a novel therapeutic target in the prevention of UV-induced skin cancer.
Asunto(s)
Carcinoma de Células Escamosas/metabolismo , Quimiocina CXCL12/metabolismo , Compuestos Heterocíclicos/química , Neoplasias Inducidas por Radiación/metabolismo , Receptores CXCR4/metabolismo , Neoplasias Cutáneas/metabolismo , Luz Solar , Animales , Bencilaminas , Células de la Médula Ósea/citología , Carcinoma de Células Escamosas/tratamiento farmacológico , Carcinoma de Células Escamosas/inmunología , Movimiento Celular , Ciclamas , Femenino , Fluoresceínas/química , Regulación de la Expresión Génica , Sistema Inmunológico , Ganglios Linfáticos/metabolismo , Ganglios Linfáticos/efectos de la radiación , Mastocitos/metabolismo , Mastocitos/efectos de la radiación , Ratones , Ratones Endogámicos C57BL , Metástasis de la Neoplasia , Neoplasias Inducidas por Radiación/tratamiento farmacológico , Neoplasias Inducidas por Radiación/inmunología , Neoplasias Cutáneas/tratamiento farmacológico , Neoplasias Cutáneas/inmunología , Succinimidas/química , Rayos UltravioletaRESUMEN
The cellular and molecular mechanisms by which UV radiation modulates inflammation and immunity while simultaneously maintaining skin homeostasis is complex and not completely understood. Similar to the effects of UV, IL-33 has potent immune-modulating properties that are mediated by the downstream induction of cytokines and chemokines. We have discovered that exposure of mice in vivo or human skin samples ex vivo to inflammatory doses of UVB induced IL-33 expression within the epidermal and dermal skin layers. Using a combination of murine cell lines and primary human cells, we demonstrate that both UV and the oxidized lipid platelet activating factor induce IL-33 expression in keratinocytes and dermal fibroblasts. Highlighting the significance of these results, we found that administering IL-33 to mice in vivo suppressed the induction of Th1-mediated contact hypersensitivity responses. This may have consequences for skin cancer growth because UV-induced squamous cell carcinomas that evade immunological destruction were found to express significantly higher levels of IL-33. Finally, we demonstrate that dermal mast cells and skin-infiltrating neutrophils closely associate with UV-induced IL-33-expressing fibroblasts. Our results therefore identify and support a role for IL-33 as an important early danger signal produced in response to inflammation-inducing UV radiation.
Asunto(s)
Carcinoma de Células Escamosas/etiología , Inflamación/etiología , Interleucinas/metabolismo , Neoplasias Cutáneas/etiología , Piel/efectos de la radiación , Rayos Ultravioleta/efectos adversos , Adulto , Animales , Western Blotting , Carcinoma de Células Escamosas/patología , Femenino , Fibroblastos/inmunología , Fibroblastos/metabolismo , Fibroblastos/efectos de la radiación , Técnica del Anticuerpo Fluorescente , Humanos , Inflamación/patología , Interleucina-33 , Queratinocitos/inmunología , Queratinocitos/metabolismo , Queratinocitos/efectos de la radiación , Mastocitos/inmunología , Mastocitos/metabolismo , Mastocitos/efectos de la radiación , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Neutrófilos/inmunología , Neutrófilos/metabolismo , Neutrófilos/efectos de la radiación , Factor de Activación Plaquetaria/metabolismo , ARN Mensajero/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Piel/inmunología , Piel/metabolismo , Neoplasias Cutáneas/patologíaRESUMEN
Outer membrane vesicles (OMVs) shed from the gastroduodenal pathogen Helicobacter pylori have measurable effects on epithelial cell responses. The aim of this study was to determine the effect of iron availability, and its basis, on the extent and nature of lipopolysaccharide (LPS) produced on H. pylori OMVs and their parental bacterial cells. Electrophoretic, immunoblotting and structural analyses revealed that LPSs of bacterial cells grown under iron-limited conditions were notably shorter than those of bacteria and OMVs obtained from iron-replete conditions. Structural analysis and serological probing showed that LPSs of iron-replete cells and OMVs expressed O-chains of Lewis(x) with a terminal Lewis(y) unit, whereas Lewis(y) expression was notably reduced on bacteria and OMVs from iron-limiting conditions. Unlike the O-chain, the core oligosaccharide and lipid A moieties of iron-replete and iron-limited bacteria and their OMVs were similar. Quantitatively, shed OMVs from iron-replete bacteria were found to be LPSenriched, whereas shed OMVs from iron-limited bacteria had a significantly reduced content of LPS. These differences were linked to bacterial ATP levels. Since iron availability affects the extent and nature of LPS expressed by H. pylori, host iron status may contribute to H. pylori pathogenesis.
Asunto(s)
Membrana Celular/inmunología , Helicobacter pylori/crecimiento & desarrollo , Helicobacter pylori/inmunología , Lipopolisacáridos/inmunología , Deficiencias de Hierro , Lipopolisacáridos/química , Estructura MolecularRESUMEN
BACKGROUND: Female CD-1/Swiss Webster mice subjected to incessant ovulation for 8 months and 12-month breeder mice both developed ovarian inclusion cysts similar to serous cystadenomas. The majority of cysts appeared to be dilated rete ovarii tubules, but high ovulation number resulted in more cortical inclusion cysts. We hypothesized that comparison of inclusion cyst pathology in animals of the same age, but with differences in total lifetime ovulation number, might allow us to determine distinguishing characteristics of the two types of cyst. METHODS: Ovaries from breeder mice (BR) or females subjected to incessant ovulation (IO) were compared at 6-, 9- and 12-months of age. Ovaries were serially sectioned and cysts characterized with regard to location and histology, E-cadherin immunoreactivity and rates of BrdU incorporation. RESULTS: Inclusion cysts developed with age in BR and IO ovaries. The majority of cysts were connected to the ovarian hilus. Two cortical inclusion cysts were observed in ten IO ovaries and one in ten BR ovaries. Low or no E-cadherin immuno-staining was seen in the OSE of all mice studied. Conversely, strong membrane immuno-staining was observed in rete ovarii epithelial cells. Variable E-cadherin immunoreactivity was seen in cells of hilar inclusion cysts, with strong staining observed in cuboidal ciliated cells and little or no staining in flat epithelial cells. Two of the three cortical cysts contained papillae, which showed E-cadherin immuno-staining at the edge of cells. However hilar and cortical cysts were not distinguishable by morphology, cell type or E-cadherin immunoreactivity. BrdU incorporation in cyst cells (1.4% [95% CI: 1.0 to 2.1]) was greater than in OSE (0.7% [95% CI: 0.4 to 1.2]) and very few BrdU-labeled cells were observed in rete ovarii at any age. Incessant ovulation significantly increased BrdU incorporation in OSE of older animals. CONCLUSION: These experiments confirm ovarian inclusion cysts develop with age in the CD-1 mouse strain, irrespective of total ovulation burden. We conclude longer periods of incessant ovulation do not lead to significant changes in inclusion cyst formation or steroidogenesis in CD-1 mice and inclusion cyst type can not be distinguished by morphology, cell proliferation rate or E-cadherin immunoreactivity.
Asunto(s)
Cruzamiento , Bromodesoxiuridina/metabolismo , Cadherinas/metabolismo , Ratones Endogámicos , Quistes Ováricos/etiología , Quistes Ováricos/metabolismo , Ovulación , Envejecimiento/sangre , Envejecimiento/metabolismo , Androstenodiona/sangre , Animales , Apoptosis , Líquido Quístico/metabolismo , Epitelio/metabolismo , Estradiol/sangre , Estradiol/metabolismo , Femenino , Immunoblotting , Inmunoquímica , Ratones , Concentración Osmolar , Quistes Ováricos/patología , Quistes Ováricos/fisiopatología , Ovario/metabolismo , Especificidad de la Especie , Testosterona/sangreRESUMEN
Epithelial ovarian cancer (EOC) is often a lethal disease because in many cases early symptoms go undetected. Although research proceeds apace, as yet there are few reliable and specific biomarkers for the early stages of the disease. EOC is an umbrella label for a highly heterogeneous collection of cancers, which includes tumours of low malignant potential, serous cystadenomas, mucinous and clear cell carcinomas, all of which are likely to arise from a number of epithelial cell types and a variety of progenitor lesions. Many, but not all types of EOC are thought to arise from the cells lining ovarian inclusion cysts. In this review, we discuss the hypotheses that have driven our ideas on epithelial ovarian carcinogenesis and examine the morphological and genetic evidence for pathways to EOC. The emergence of laser-capture microdissection and expression profiling by microarray technologies offers the promise of defining these pathways more accurately, as well as providing us with the tools for earlier diagnosis.