Regulation of Arachidonic Acid Pathway and Eosinophilic Inflammation in Chronic Rhinosinusitis/ Nasal Polyposis. Potential Role of Staphylococcus aureus Enterotoxins

linked to inflammation. Furthermore, EP2 and EP4 receptor expression was increased in chronic rhinosinusitis and nasal polyp subjects in contrast to EP1 and EP3, which were down regulated in the polyp group, suggesting a distinctive role of these receptors in the pathophysiology of nasal polyposis. Finally, based on our previous findings and parallel work of our group, we studied the influence of S. aureus enterotoxins in the regulation of both eosinophilic inflammatory and eicosanoid pathways. We first show that nasal polyposis/aspirin intolerance was associated with increased concentrations of eosinophil-related mediators, as well as of IgE antibodies to S. aureus enterotoxins. Furthermore, eicosanoid release evaluated in nasal polyp patients showed an increase of leukotrienes and lipoxin A4 in patients with immune response - 18 - against S. aureus enterotoxins, which seem to be correlated to the enterotoxin-derived inflammatory reaction and unrelated to asthma and allergy conditions. These findings were extended to structural cells (fibroblasts). These in vitro experiments demonstrated that S. aureus enterotoxin B could regulate the production of PGE2 and influence important cell physiological mechanisms like growth and migration. The results of our studies provide new insights about the molecular interactions and the role of bacterial infection in the regulation of two crucial inflammatory mechanisms operating in airway human diseases, the eicosanoid biosynthetic and the eosinophilic pathway

LTD4 and TGF-β1 induce the expression of metalloproteinase-1 in chronic rhinosinusitis via a cysteinyl leukotriene receptor 1-related mechanism

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Staphylococcus aureus enterotoxin B regulates prostaglandin E-2 synthesis, growth, and migration in nasal tissue fibroblasts

Background. Superantigens and eicosanoids are important amplifiers and regulators of inflammation in airway diseases. We therefore studied the possible influence of Staphylococcus aureus enterotoxin B ( SEB) on the cyclooxygenase ( COX) pathway and basic functions of airway structural cells. Methods. Fibroblasts were isolated from nasal inferior turbinate tissue and cultured in the presence of different concentrations of SEB. Preincubation with interferon ( IFN)-gamma was performed to induce expression of major histocompatibility complex ( MHC) class II receptors. Prostaglandin E2 ( PGE(2)) production was assayed by enzyme-linked immunosorbent assay, and levels of COX-2 and prostanoid E receptors 1-4 ( EP1-4) were assayed by real-time polymerase chain reaction. Migration and growth tests were performed, and SEB was localized within the cells by confocal microscopy. Results. Stimulation with IFN-gamma and SEB significantly down-regulated PGE2, COX-2, and EP2 expression but not EP1, EP3, or EP4 expression. The enterotoxin blocked cell growth but increased the fibroblast migration rate. SEB was localized within the cell in the presence and absence of MHC-II, suggesting that mechanisms other than conventional binding may allow the enterotoxin to enter the cell. Conclusions. These findings may have major implications for our understanding of the role played by bacterial superantigens in regulating the inflammatory and remodeling mechanisms of upper airway diseases and hence may help elucidate the pathophysiology of these diseases

Enhanced release of IgE-dependent early phase mediators from nasal polyp tissue

Background: The mast cell is a crucial effector cell in allergic rhinitis and other inflammatory diseases. During the acute allergic reaction preformed mediators such as histamine, but also de novo produced mediators such as leukotrienes (LTC4/D-4/E-4) and prostaglandins (PGD(2)) are released. Mast cells represent targets for therapeutic intervention, and thus a human ex-vivo model to stimulate mast cells taken from mucosal sites would be instrumental for drug intervention studies. We have aimed to activate mast cells within ex-vivo human nasal tissue by IgE/anti-IgE specific (epsilon chain specific) stimulations and in this respect to test the usability of nasal polyps versus inferior turbinates Methods: Biopsy samples were collected from patients with nasal polyps and inferior turbinates from patients who underwent sinus or septal surgery. Tissue fragments were primed with IgE 1 mu g/ml for 60 minutes and then stimulated for 30 minutes with tissue culture medium (negative control), anti-IgE 10 mu g/ml, anti-IgE 30 mu g/ml and ionomycin 10 mu M (positive control). Histamine, leukotrienes and PGD2 were measured in supernatants. To help provide an understanding of the extent of the response, the number of tryptase and Fc epsilon RI alpha positive cells was evaluated by means of immunohistochemistry and the Fc epsilon RI alpha-chain was measured by means of quantitative PCR in the nasal polyp and inferior turbinate tissues. Finally, the correlation between IgE concentrations in the nasal tissue and the release of mediators was analysed. Results: Stimulations with anti-IgE on IgE-primed nasal tissue fragments lead to a concentration-dependent release of histamine, leukotrienes and PGD(2). The release of these early phase mediators was significantly higher in nasal polyps compared to inferior turbinates, although tryptase, Fc epsilon RI alpha positive cells and Fc epsilon RI alpha-chain transcripts were equally present in both groups. No correlation was found between baseline concentrations of IgE, and the release of histamine, LTC4/LTD4/LTE4 and PGD2 after stimulation. Conclusion: This human nasal challenge model mimics the allergic early phase reaction. The release of histamine, cys-leukotrienes and PGD(2) was significantly higher in nasal polyps versus inferior turbinates, however, this observation could not be explained by differences in mast cell or Fc epsilon RI+ cell numbers

Epithelium and stroma from nasal polyp mucosa exhibits inverse expression of TGF- beta(1) as compared with healthy nasal mucosa

Objective: To evaluate TGF-beta(1) expression in polypoid mucosa (epithelium and stroma) of patients with chronic rhinosinusitis with nasal polyposis (CRSwNP).Methods: Cross-sectional study with two groups: 17 patients with nasal polyposis and 11 controls. Polyps and normal nasal mucosa were processed by immunohistochemical methods for TGF-beta 1 visualization. Then, the percentage of TGF-beta 1 expression in stroma and epithelium was objectively quantified using UT Morph software.Results: A lower percentage of positive expression was found in the epithelium of CRSwNP patients (32.44%) versus normal controls (55.91%) (p < 0.05), and a higher percentage of positive expression in the stroma of CRSwNP patients (23.24%) versus controls (5.88%) (p < 0.05).Conclusion: the lower percentage of TGF-beta(1) expression in the nasal epithelium of CRSwNP patients may have an impact on epithelium-directed topical treatments employed in this patient population.Universidade Federal de São Paulo, Dept Otolaryngol Head & Neck Surg, São Paulo, BrazilUniv Ghent, Ghent Univ Hosp, Dept Otorhinolaryngol, Upper Airway Res Lab, B-9000 Ghent, BelgiumUniversidade Federal de São Paulo, Dept Pathol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Otolaryngol Head & Neck Surg, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Pathol, São Paulo, BrazilWeb of Scienc

Staphylococcal enterotoxin B influences the DNA methylation pattern in nasal polyp tissue : a preliminary study

Staphylococcal enterotoxins may influence the pro-inflammatory pattern of chronic sinus diseases via epigenetic events. This work intended to investigate the potential of staphylococcal enterotoxin B (SEB) to induce changes in the DNA methylation pattern. Nasal polyp tissue explants were cultured in the presence and absence of SEB; genomic DNA was then isolated and used for whole genome methylation analysis. Results showed that SEB stimulation altered the methylation pattern of gene regions when compared with non stimulated tissue. Data enrichment analysis highlighted two genes: the IKBKB and STAT-5B, both playing a crucial role in T- cell maturation/activation and immune response

Covalent Cysteine Targeting of Bruton's Tyrosine Kinase (BTK) Family by Withaferin-A Reduces Survival of Glucocorticoid-Resistant Multiple Myeloma MM1 Cells

Simple Summary Glucocorticoid therapy resistance in B-cell malignancies is often associated with constitutive activation of tyrosine kinases. Novel anticancer drugs targeting hyperactivated tyrosine kinases, such as Bruton's tyrosine kinase (BTK), have, therefore, gained much interest over the past few decades and have already been approved for clinical use. In this study, we compared the therapeutic efficacy of the phytochemical kinase inhibitor withaferin A with the clinically approved BTK inhibitor ibrutinib to target hyperactivated tyrosine kinase signaling in glucocorticoid-resistant multiple myeloma cells. Our results demonstrate that withaferin A-induced cell death of glucocorticoid-resistant MM1R cells involves covalent cysteine targeting of multiple Hinge-6 domain type tyrosine kinases of the kinase cysteinome classification, including BTK. Multiple myeloma (MM) is a hematological malignancy characterized by plasma cells' uncontrolled growth. The major barrier in treating MM is the occurrence of primary and acquired therapy resistance to anticancer drugs. Often, this therapy resistance is associated with constitutive hyperactivation of tyrosine kinase signaling. Novel covalent kinase inhibitors, such as the clinically approved BTK inhibitor ibrutinib (IBR) and the preclinical phytochemical withaferin A (WA), have, therefore, gained pharmaceutical interest. Remarkably, WA is more effective than IBR in killing BTK-overexpressing glucocorticoid (GC)-resistant MM1R cells. To further characterize the kinase inhibitor profiles of WA and IBR in GC-resistant MM cells, we applied phosphopeptidome- and transcriptome-specific tyrosine kinome profiling. In contrast to IBR, WA was found to reverse BTK overexpression in GC-resistant MM1R cells. Furthermore, WA-induced cell death involves covalent cysteine targeting of Hinge-6 domain type tyrosine kinases of the kinase cysteinome classification, including inhibition of the hyperactivated BTK. Covalent interaction between WA and BTK could further be confirmed by biotin-based affinity purification and confocal microscopy. Similarly, molecular modeling suggests WA preferably targets conserved cysteines in the Hinge-6 region of the kinase cysteinome classification, favoring inhibition of multiple B-cell receptors (BCR) family kinases. Altogether, we show that WA's promiscuous inhibition of multiple BTK family tyrosine kinases represents a highly effective strategy to overcome GC-therapy resistance in MM

Nasal polyposis : more than a chronic inflammatory disorder : a disease of mechanical dysfunction : the São Paulo position

Introduction The importance of our study lies in the fact that we have demonstrated the occurrence of mechanical dysfunction within polypoid tissues, which promotes the development of polyps in the nasal cavity. Objective To change the paradigm of nasal polyposis (NP). In this new conception, the chronic nasal inflammatory process that occurs in response to allergies, to pollution, to changes in the epithelial barrier, or to other factors is merely the trigger of the development of the disease in individuals with a genetic predisposition to an abnormal tissue remodeling process, which leads to a derangement of the mechanical properties of the nasal mucosa and, consequently, allows it to grow unchecked. Data Synthesis We propose a fundamentally new approach to intervening in the pathological process of NP, addressing biomechanical properties, fluid dynamics, and the concept of surface tension. Conclusion The incorporation of biomechanical knowledge into our understanding of NP provides a new perspective to help elucidate the physiology and the pathology of nasal polyps, and new avenues for the treatment and cure of NP

Dendritic cell subset expression in severe chronic rhinosinusitis with nasal polyps

Purpose of review Two main pillars are implicated in nasal polyposis development: a severe imbalance in immunomodulation and a mechanical dysfunction because of an abnormal remodeling process. Dendritic cells play a crucial role in the link between innate and adaptive immune response and orchestrating the T-cell response and are implicated in the severe inflammatory process found in nasal polypoid tissue. This review summarizes the existent knowledge about dendritic cells in nasal polyposis. Recent findings Dendritic cells are found increased in nasal polyposis, regardless of subset. Of interest, plasmacytoid dendritic cells are decreased in patients with a more severe Th2 profile, suggesting an important role of the cytokines milieu in their functional response or that plasmacytoid dendritic cell could act mitigating the inflamed process found in polypoid tissue. Summary Understanding the dendritic cell subset expression in different environments, as well as the effect of these subsets on T-cell differentiation will greatly improve the development of new therapies in nasal polyposis.Univ Antwerp, Dept Biomed Sci, Lab Proteinchem, Prote Epigenet Signaling, Antwerp, BelgiumUniv Fed Sao Paulo, ENT Res Lab, Dept Otolaryngol Head & Neck Surg, Rua Otonis,700 Piso Super,Vila Clementino, BR-04025002 Sao Paulo, SP, BrazilUniv Fed Sao Paulo, ENT Res Lab, Dept Otolaryngol Head & Neck Surg, Rua Otonis,700 Piso Super,Vila Clementino, BR-04025002 Sao Paulo, SP, BrazilWeb of Scienc