IKKβ overexpression together with a lack of tumour suppressor genes causes ameloblastic odontomas in mice

Odontogenic tumours are a heterogeneous group of lesions that develop in the oral cavity region and are characterized by the formation of tumoural structures that differentiate as teeth. Due to the diversity of their histopathological characteristics and clinical behaviour, the classification of these tumours is still under debate. Alterations in morphogenesis pathways such as the Hedgehog, MAPK and WNT/β-catenin pathways are implicated in the formation of odontogenic lesions, but the molecular bases of many of these lesions are still unknown. In this study, we used genetically modified mice to study the role of IKKβ (a fundamental regulator of NF-κB activity and many other proteins) in oral epithelial cells and odontogenic tissues. Transgenic mice overexpressing IKKβ in oral epithelial cells show a significant increase in immune cells in both the oral epithelia and oral submucosa. They also show changes in the expression of several proteins and miRNAs that are important for cancer development. Interestingly, we found that overactivity of IKKβ in oral epithelia and odontogenic tissues, in conjunction with the loss of tumour suppressor proteins (p53, or p16 and p19), leads to the appearance of odontogenic tumours that can be classified as ameloblastic odontomas, sometimes accompanied by foci of secondary ameloblastic carcinomas. These tumours show NF-κB activation and increased β-catenin activity. These findings may help to elucidate the molecular determinants of odontogenic tumourigenesis and the role of IKKβ in the homoeostasis and tumoural transformation of oral and odontogenic epitheliaThis work was funded by project PI17/00578, from the “Instituto de Salud Carlos III” (Ministry of Science, Innovation and Universities) and co-funded by the European Regional Development Fund, and approved by the Ethics Committee of our Institution. It has been founded also by projects CB16/12/00228, PI16/00161, RD16/0011/0011, RD12/0019/0023 and SAF2017–84248-PS

TNF-α and IL-10 downregulation and marked oxidative stress in Neuromyelitis Optica

<p>Abstract</p> <p>Background</p> <p>Neuromyelitis optica is a central nervous system demyelinating and inflammatory syndrome. The objective of this study is to identify cytokines related to the cellular immune response as well as blood brain barrier integrity and oxidative stress.</p> <p>Methods</p> <p>We performed a molecular characterization of cellular immune response and oxidative stress in serum from relapsing-NMO (R-NMO) patients and established the correlations between the clinical measurements and molecular parameters using the Bayesian approach.</p> <p>Serum samples from 11 patients with R-NMO diagnosed according to Wingerchuk criteria and matched in terms of age, gender and ethnicity with the healthy controls were analyzed. The levels of TNF-<it>α</it>, IFN-<it>γ</it>, IL-10, MMP-9, TIMP-1 and oxidative stress markers: malondialdehyde, advanced oxidation protein products, peroxidation potential, superoxide dismutase, catalase, and total hydroperoxides were measured.</p> <p>Results</p> <p>We found almost undetectable levels of TNF-<it>α</it>, a decreased production of IL-10 and a significant up-regulation of every oxidative stress biomarker studied. The insufficient production of TNF-<it>α </it>and IL-10 in R-NMO patients, which are two important players of T cell mediated immunoregulation, suggest an effector – regulator imbalance. The overproduction of oxygen reactive species as a consequence of the chronic inflammatory milieu is reflected on the excess of oxidative damage mediators detected. Furthermore, Multidimensional Scaling and a Bayesian linear regression model revealed a significant linear dependence between Expanded Disability Status Scale Kurtzke and TIMP-1; pointing to a possible predictive or prognostic value of this clinical-molecular relationship.</p> <p>Conclusion</p> <p>These results suggest that there is a breakdown in immunoregulatory mechanisms and noteworthy pro-oxidant environment contributing to NMO pathogenesis.</p

Exocrine pancreatic disorders in transsgenic mice expressing human keratin 8

9 pages, 6 figures, 2 tables.-- et al.Keratins K8 and K18 are the major components of the intermediate-filament cytoskeleton of simple epithelia. Increased levels of these keratins have been correlated with various tumor cell characteristics, including progression to malignancy, invasive behavior, and drug sensitivity, although a role for K8/K18 in tumorigenesis has not yet been demonstrated. To examine the function of these keratins, we generated mice expressing the human K8 (hk8) gene, which leads to a moderate keratin-content increase in their simple epithelia. These mice displayed progressive exocrine pancreas alterations, including dysplasia and loss of acinar architecture, redifferentiation of acinar to ductal cells, inflammation, fibrosis, and substitution of exocrine by adipose tissue, as well as increased cell proliferation and apoptosis. Histological changes were not observed in other simple epithelia, such as the liver. Electron microscopy showed that transgenic acinar cells have keratins organized in abundant filament bundles dispersed throughout the cytoplasm, in contrast to control acinar cells, which have scarce and apically concentrated filaments. The phenotype found was very similar to that reported for transgenic mice expressing a dominant-negative mutant TGF-β type II receptor (TGFβRII mice). We show that these TGFβRII mutant mice also have elevated K8/K18 levels. These results indicate that simple epithelial keratins play a relevant role in the regulation of exocrine pancreas homeostasis and support the idea that disruption of mechanisms that normally regulate keratin expression in vivo could be related to inflammatory and neoplastic pancreatic disorders.This work was supported in part by grant PB 94-1230 of the Spanish Dirección General de Investigación Científica y Tecnológica.Peer reviewe

Estudio de la regulacion de la expresion y de la funcion de la queratina 8 humana de epitelios simples

Centro de Informacion y Documentacion Cientifica (CINDOC). C/Joaquin Costa, 22. 28002 Madrid. SPAIN / CINDOC - Centro de Informaciòn y Documentaciòn CientìficaSIGLEESSpai

Intermediate Filaments Interact with Dormant Ezrin in Intestinal Epithelial Cells

Ezrin connects the apical F-actin scaffold to membrane proteins in the apical brush border of intestinal epithelial cells. Yet, the mechanisms that recruit ezrin to the apical domain remain obscure. Using stable CACO-2 transfectants expressing keratin 8 (K8) antisense RNA under a tetracycline-responsive element, we showed that the actin-ezrin scaffold cannot assemble in the absence of intermediate filaments (IFs). Overexpression of ezrin partially rescued this phenotype. Overexpression of K8 in mice also disrupted the assembly of the brush border, but ezrin distributed away from the apical membrane in spots along supernumerary IFs. In cytochalasin D-treated cells ezrin localized to a subapical compartment and coimmunoprecipitated with IFs. Overexpression of ezrin in undifferentiated cells showed a Triton-insoluble ezrin compartment negative for phospho-T567 (dormant) ezrin visualized as spots along IFs. Pulse-chase analysis showed that Triton-insoluble, newly synthesized ezrin transiently coimmunoprecipitates with IFs during the first 30 min of the chase. Dormant, but not active (p-T567), ezrin bound in vitro to isolated denatured keratins in Far-Western analysis and to native IFs in pull-down assays. We conclude that a transient association to IFs is an early step in the polarized assembly of apical ezrin in intestinal epithelial cells

Functional Inactivation of CYLD Promotes the Metastatic Potential of Tumor Epidermal Cells

CYLD is a tumor-suppressor gene mutated in the skin appendage tumors cylindromas, trichoepitheliomas, and spiradenomas. We have performed in vivo metastasis assays in nude mice and found that the loss of the deubiquitinase function of CYLD in squamous cell carcinoma (SCC) cells greatly enhances the lung metastatic capability of these cells. These metastases showed several characteristics that make them distinguishable from those carrying a functional CYLD, such as robust angiogenesis, increased expression of tumor malignancy markers of SCCs, and a decrease in the expression of the suppressor of metastasis Maspin. Restoration of Maspin expression in the epidermal SCC cells defective in CYLD deubiquitination function significantly reduces their ability to form metastases, thereby suggesting that the decrease in the levels of Maspin expression plays an important role in the acquisition of metastatic potential of these cells. In addition, we have characterized Maspin downregulation in cylindromas, trichoepitheliomas, and spiradenomas carrying functional inactivating mutations of CYLD, also providing an evidence of the correlation between impaired CYLD function and Maspin decreased expression in vivo in human tumors