Translational research into the effects of cigarette smoke on inflammatory mediators and epithelial TRPV1 in Crohn's disease.

Crohn's disease is a pathological condition of the gastro-intestinal tract, causing severe transmural inflammation in the ileum and/or colon. Cigarette smoking is one of the best known environmental risk factors for the development of Crohn's disease. Nevertheless, very little is known about the effect of prolonged cigarette smoke exposure on inflammatory modulators in the gut. We examined the effect of cigarette smoke on cytokine profiles in the healthy and inflamed gut of human subjects and in the trinitrobenzene sulphonic acid mouse model, which mimics distal Crohn-like colitis. In addition, the effect of cigarette smoke on epithelial expression of transient receptor potential channels and their concurrent increase with cigarette smoke-augmented cytokine production was investigated. Active smoking was associated with increased IL-8 transcription in ileum of controls (p < 0,001; n = 18-20/group). In the ileum, TRPV1 mRNA levels were decreased in never smoking Crohn's disease patients compared to healthy subjects (p <0,001; n = 20/group). In the colon, TRPV1 mRNA levels were decreased (p = 0,046) in smoking healthy controls (n = 20/group). Likewise, healthy mice chronically exposed to cigarette smoke (n = 10/group) showed elevated ileal Cxcl2 (p = 0,0075) and colonic Kc mRNA levels (p = 0,0186), whereas TRPV1 mRNA and protein levels were elevated in the ileum (p = 0,0315). Although cigarette smoke exposure prior to trinitrobenzene sulphonic acid administration did not alter disease activity, increased pro-inflammatory cytokine production was observed in the distal colon (Kc: p = 0,0273; Cxcl2: p = 0,104; Il1-ß: p = 0,0796), in parallel with the increase of Trpv1 mRNA (p < 0,001). We infer that CS affects pro-inflammatory cytokine expression in healthy and inflamed gut, and that the simultaneous modulation of TRPV1 may point to a potential involvement of TRPV1 in cigarette smoke-induced production of inflammatory mediators.

Chronic rhinosinusitis: assessment of changes in nociceptive neurons.

BACKGROUND: Pain is a major symptom of chronic rhinosinusitis (CRS). It is mainly associated with CRS without nasal polyps (CRSsNP) and has a major impact in the decision to move on to surgery. Patients with CRS with nasal polyps (CRSwNP) are characterized by trigeminal hypoesthesia and suffer from less pain. The aim of this study was to investigate whether CRS induces alterations in the peripheral nociceptive neurons, mainly focusing on quantitative changes. METHODS: Sinus mucosa and inferior turbinate (IT) samples were obtained from patients with CRS, and IT tissue of healthy patients served as controls. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) was performed for neuronal markers including CNTNAP2, FAM19A1, GFRA2, NEFH, NTRK1, PLXNC1, RET, SCN10A, SCN11A, TRPV1, and PGP 9.5; enzyme-linked immunosorbent assay (ELISA) was performed for KCNK18, SCN10A, MRGPRD, and MAP2. For PGP 9.5, immunohistochemistry was additionally used to analyze tissue slides. RESULTS: We included 35 patients with CRSsNP, 47 patients with CRSwNP, and 18 control patients. No differences in expression of the neuronal markers were observed between CRSsNP, CRSwNP, and controls. SCN10A was the only marker exclusively expressed on nociceptive neurons in sinus tissue. No histological difference in nerve fibers was observed between sinus mucosa of both phenotypes. CONCLUSION: Our results indicate that the nociceptive nerve density in CRSwNP is not lower than in CRSsNP, as was assumed previously. The nociceptive neurons in sinonasal mucosa cannot be classified into subtypes due to the lack of specificity of the respective marker genes. Our findings question the generally accepted claim that nasal polyp tissue does not contain any nerves.

Innate lymphoid cells in the upper airways: importance of CD117 and IL-1RI expression.

Although type 1, 2 and 3 innate lymphoid cells (ILC1s, ILC2s and ILC3s, respectively) are emerging as important cell populations regulating tissue homeostasis, remodelling and inflammation, a vast majority of our knowledge stems from in vitro and murine experiments, and requires thorough confirmation in human diseases.Relative levels of ILCs were evaluated by means of flow cytometry in freshly resected human upper airways mucosa of patients with chronic rhinosinusitis without nasal polyps (CRSsNP) and with nasal polyps (CRSwNP), taking into account the patient's clinical parameters and disease comorbidities.We report that the CD117 and interleukin-receptor type I (IL-1RI) expression status of human ILC2s depends on the local tissue environment. Only CD117+ IL-1RI+ ILC2s, exclusively present in CRSwNP, possess an interrelationship with type 2 T-helper cell cytokine and eosinophil levels in human upper airway mucosa. In CRSsNP, mainly CD117-IL-1RI- ILC2s are increased, yielding lower eosinophilia in this disease despite the high levels of ILC2s.These data unveil that the CD117- and CD117+ fractions within the native human ILC2 population are not a random phenomenon, in contrast to what could be concluded from in vitro data, and that the IL-1RI expression is not ubiquitous in ILC2s in vivo in humans, which cannot be assessed via in vitro and murine experiments.

Staphylococcus aureus Induces a Mucosal Type 2 Immune Response via Epithelial Cell-derived Cytokines.

RATIONALE: Chronic rhinosinusitis with nasal polyps is characterized by a T-helper cell type 2-skewed upper airway inflammation. Mucosal Staphylococcus aureus colonization is found in the majority of patients with nasal polyps. S. aureus is known to induce type 2 cytokine release via enterotoxins. OBJECTIVES: To investigate the impact of non-enterotoxin-producing S. aureus on type 2 cytokine release. METHODS: TSLP (thymic stromal lymphopoietin), IL-33, and type 2 cytokines were assessed in a human mucosal tissue model upon S. aureus infection. MEASUREMENTS AND MAIN RESULTS: S. aureus exposure increased the expression of IL-33, TSLP, IL-5, and IL-13 in nasal polyp tissue, accompanied by elevated expression levels of TSLP and IL-33 receptors, predominantly on CD3+ T cells. S. aureus infection led to the release of TSLP, but not IL-33, IL-5, or IL-13, from healthy inferior turbinate tissue. In contrast, S. epidermidis did not induce any epithelial cell-derived cytokines in nasal polyp or healthy tissue. S. aureus infection also increased the release of IL-33 and TSLP in BEAS-2B epithelial cells, accompanied by activation of NF-κB (nuclear factor κB) pathways. Incubation with CU-CPT22, a specific Toll-like receptor 2 antagonist, significantly reduced the S. aureus-induced release of TSLP and IL-33, and the activity of the NF-κB signal in BEAS-2B cells. CONCLUSIONS: This study demonstrates for the first time that S. aureus can directly induce epithelial cell-derived cytokine release via binding to Toll-like receptor 2, and may thereby propagate type 2 cytokine expression in nasal polyp tissue.

Staphylococcal serine protease-like proteins are pacemakers of allergic airway reactions to Staphylococcus aureus.

BACKGROUND: A substantial subgroup of asthmatic patients have "nonallergic" or idiopathic asthma, which often takes a severe course and is difficult to treat. The cause might be allergic reactions to the gram-positive pathogen Staphylococcus aureus, a frequent colonizer of the upper airways. However, the driving allergens of S aureus have remained elusive. OBJECTIVE: We sought to search for potentially allergenic S aureus proteins and characterize the immune response directed against them. METHODS: S aureus extracellular proteins targeted by human serum IgG4 were identified by means of immunoblotting to screen for potential bacterial allergens. Candidate antigens were expressed as recombinant proteins and used to analyze the established cellular and humoral immune responses in healthy adults and asthmatic patients. The ability to induce a type 2 immune response in vivo was tested in a mouse asthma model. RESULTS: We identified staphylococcal serine protease-like proteins (Spls) as dominant IgG4-binding S aureus proteins. SplA through SplF are extracellular proteases of unknown function expressed by S aureus in vivo. Spls elicited IgE antibody responses in most asthmatic patients. In healthy S aureus carriers and noncarriers, peripheral blood T cells elaborated TH2 cytokines after stimulation with Spls, as is typical for allergens. In contrast, TH1/TH17 cytokines, which dominated the response to S aureus α-hemolysin, were of low concentration or absent. In mice inhalation of SplD without adjuvant induced lung inflammation characterized by TH2 cytokines and eosinophil infiltration. CONCLUSION: We identify Spls as triggering allergens released by S aureus, opening prospects for diagnosis and causal therapy of asthma.

Allergen-Dependent Differences in ILC2s Frequencies in Patients With Allergic Rhinitis.

PURPOSE: Group 2 innate lymphoid cells (ILC2s) are a novel population of lineage-negative cells that induce innate type 2 responses by producing the critical Th2-type cytokines IL-5 and IL-13 in response to IL-25 and IL-33 stimulation. ILC2s accumulation in the peripheral blood of patients with allergic rhinitis (AR) is controversial; the precise role of ILC2s in the immunopathogenesis of AR is still not clear. We investigated the role of ILC2s in phenotypic AR sensitized to distinct allergens. METHODS: Flow cytometric analysis of the peripheral blood of 7 healthy controls (HCs), 9 patients monosensitized to house dust mite (HDM), and 8 patients monosensitized to mugwort was performed to quantify ILC2s frequency. Peripheral blood mononuclear cells (PBMCs) were isolated from HDM-AR and mugwort-AR patients, and Lineage⁻ and Lineage⁺ cells were separated using a fluorescence-activated cell sorter (FACS). IL-5 and IL-13 levels in the supernatants of PBMCs, and Lineage⁻ and Lineage⁺ cells stimulated with IL-25 and/or IL-33 combined with IL-2 in vitro were assessed using the Milliplex magnetic bead kit. RESULTS: The percentage of ILC2s was significantly elevated in HDM-AR patients compared to mugwort-AR patients and HCs, while no significant difference was found between mugwort-AR patients and HCs. IL-33±IL-25 plus IL-2 induced a significantly greater release of IL-5 and IL-13 in the PBMCs of HDM-AR patients compared to PBMCs of mugwort-AR patients. IL-25 plus IL-2 also induced a significantly greater release of IL-13 in the PBMCs of HDM-AR patients compared to PBMCs of mugwort-AR patients. Stimulation with IL-33 and/or IL-25 combined with IL-2 also induced a significantly greater IL-5 and IL-13 release from Lineage⁻ cells compared to Lineage⁺ cells. CONCLUSIONS: AR patients sensitized to HDM or mugwort allergen have distinct phenotypic and functional profiles in ILC2s frequencies. ILC2s mediate major type 2 immunity in the development of HDM-AR and may be a potential therapeutic target.

Systemic expression of inflammatory mediators in patients with chronic rhinosinusitis and nasal polyps with and without Aspirin Exacerbated Respiratory Disease.

BACKGROUND: Systemic reactions are related to the pathogenesis of Aspirin Exacerbated Respiratory Disease (AERD). With this work we wanted to study the changes in the systemic levels of inflammatory mediators in both baseline and after oral aspirin challenge in patients with and without AERD. METHODS: Patients with nasal polyposis and asthma with AERD (n=20) and without (n=18) were orally challenged with aspirin in a single-blind placebo controlled study. Serum samples and urine were collected before and 6h after placebo and aspirin oral challenges. Serum levels of inflammatory mediators were assayed by using the Luminex technology and ELISA. The concentrations of 9-alpha, 11-beta prostaglandin F2, and leukotriene E4 (uLTE4) were measured in urine samples by ELISA. The expression of T-cell surface markers was analyzed in peripheral blood mononuclear cells isolated before and after the challenges. RESULTS: AERD patients showed significantly higher baseline levels of s-IL-5R-alpha, uLTE4 and percentage of CD4(+)CD25(+)CD127(pos) and CD4(+)CD45RA(-)CD45RO(+) but decreased levels of TGF-ß1 and number of CD4(+)CD25(+)CD127(neg) cells. Aspirin challenge induced the release of uLTE4, IL-6 and increased the number of CD4(+)CD45RA(-)CD45RO(+) memory T-cells only in AERD patients but failed to reduce the levels of sCD40L as observed in non-AERD subjects. Further, IL-8 and sIL-5R-alpha levels directly correlated with the PD20ASA and the effects of aspirin on IL-6 and number of memory T-cells was more pronounced in subjects showing more strong reaction (bronchial and nasal). CONCLUSIONS: AERD patients have a differential baseline inflammatory pattern that supports the role inflammation as underlying mechanism of the disease. Systemic response to oral aspirin challenge was related to an increase in serum IL-6 and the number of circulating memory T-cells in AERD patients.

Differential release and deposition of S100A8/A9 proteins in inflamed upper airway tissue.

Intracellular Ca(2+)-binding S100A8/A9 proteins gain novel functions when released during inflammation. The exact outcome of their extracellular function depends on the local tissue environment in which they are released; both anti-inflammatory and pro-inflammatory responses are described, modulating the immune system by binding Toll-like receptor (TLR)-4 or the receptor for advanced glycation end-products (RAGE). However, the contribution of the proteins in the pathophysiology of chronic rhinosinusitis (CRS) remains unclear.Homomeric S100A8 and S100A9, and heteromeric S100A8/A9 proteins were evaluated in CRS with/without nasal polyps (CRSw/sNP) and controls. Functional responses were assessed in polyp tissue stimulated with S100 proteins in the presence of TLR-4 and RAGE blocking antibodies.S100A8, S100A9 and S100A8/A9 protein levels were significantly higher in CRSwNP patients, showing increased deposition on extracellular matrix (ECM) structures of CRSwNP tissue in contrast to CRSsNP and controls. In the presence of Staphylococcus aureus, S100A8/A9 is released from neutrophils and from the ECM. Extracellular S100A8 and S100A9 proteins induced increased levels of diverse inflammatory mediators via TLR-4 engagement.The inflammatory/remodelling characteristics of CRSwNP specifically allow increased retention of S100A8, S100A9 and S100A8/A9 proteins in the ECM of CRSwNP tissue. Upon release, homodimeric proteins act as a local danger signal inducing inflammatory mediators, predominantly via TLR-4 activation.

Differential cytokine profiles upon comparing selective versus classic glucocorticoid receptor modulation in human peripheral blood mononuclear cells and inferior turbinate tissue.

BACKGROUND: Glucocorticoid Receptor agonists, particularly classic glucocorticoids, are the mainstay among treatment protocols for various chronic inflammatory disorders, including nasal disease. To steer away from steroid-induced side effects, novel GR modulators exhibiting a more favorable therapeutic profile remain actively sought after. Currently, the impact of 2-(4-acetoxyphenyl)-2-chloro-N-methylethylammonium chloride a plant-derived selective glucocorticoid receptor modulator named compound A, on cytokine production in ex vivo human immune cells and tissue has scarcely been evaluated. METHODS AND RESULTS: The current study aimed to investigate the effect of a classic glucocorticoid versus compound A on cytokine and inflammatory mediator production after stimulation with Staphylococcus aureus-derived enterotoxin B protein in peripheral blood mononuclear cells (PBMCs) as well as in inferior nasal turbinate tissue. To this end, tissue fragments were stimulated with RPMI (negative control) or Staphylococcus aureus-derived enterotoxin B protein for 24 hours, in presence of solvent, or the glucocorticoid methylprednisolone or compound A at various concentrations. Supernatants were measured via multiplex for pro-inflammatory cytokines (IL-1ß, TNFα) and T-cell- and subset-related cytokines (IFN-γ, IL-2, IL-5, IL-6, IL-10, and IL-17). In concordance with the previously described stimulatory role of superantigens in the development of nasal polyposis, a 24h Staphylococcus aureus-derived enterotoxin B protein stimulation induced a significant increase of IL-2, IL-1ß, TNF-α, and IL-17 in PBMCs and in inferior turbinates and of IL-5 and IFN-γ in PBMCs. CONCLUSION: Notwithstanding some differences in amplitude, the overall cytokine responses to methylprednisolone and compound A were relatively similar, pointing to a conserved and common mechanism in cytokine transrepression and anti-inflammatory actions of these GR modulators. Furthermore, these results provide evidence that selective glucocorticoid receptor modulator-mediated manipulation of the glucocorticoid receptor in human tissues, supports its anti-inflammatory potential.

Mixed T helper cell signatures in chronic rhinosinusitis with and without polyps.

UNLABELLED: In chronic rhinosinusitis (CRS) different phenotypes have been reported based on cytokine profile and inflammatory cell patterns. The aim of this study was to characterize the intracytoplasmatic cytokines of T cells infiltrating the inflamed sinonasal mucosa. METHODS: Infiltrated T cells and tissue homogenates from sinonasal mucosal samples of 7 healthy subjects, 9 patients with CRS without nasal polyp (CRSsNP), 15 with CRS with nasal polyps (CRSwNP) and 5 cystic fibrosis patients (CF-NP) were analyzed for cytokine expression using flow cytometry and multiplex analysis respectively. Intracytoplasmic cytokinesin T cells were analyzed after stimulation of nasal polyps with Staphylococcus aureus enterotoxin B for 24 hours. RESULTS: The number of T cells per total living cells was significantly higher in patients with CRSwNP vs. CRSsNP and controls. 85% of the CD4(+) T cells showed to be memory T cells. The effector T cells present in all tissues have a predominant Th1 phenotype. Only in CRSwNP, a significant fraction of T cells produced the Th2 cytokines IL-4 and IL-5, while nasal polyps from CF patients were characterized by a higher CD4/CD8 T cell ratio and an increased number of Th17 cells. 24 h stimulation with SEB resulted in a significant induction of CD4(+) T cells producing IL-10 (Tr1 cells). CONCLUSION: T cell cytokine patterns in healthy and inflamed sinonasal mucosa revealed that Th2 cells (IL-4 and IL-5 producing cells) are significantly increased in CRSwNP mucosal inflammation. Exposure to SEB stimulates Tr1 cells that may contribute to the Th2 bias in CRSwNP.

The expression of dendritic cell subsets in severe chronic rhinosinusitis with nasal polyps is altered.

BACKGROUND: Chronic rhinosinusitis with nasal polyps (CRSwNP) is characterized as a Th2-driven disease. Activated dendritic cells (DCs) are the main T-cell activators; their role in the chronic inflammatory process of nasal polyposis is still unclear. METHODS: The regulation of DC subsets was analyzed in nasal polyp tissue from CRSwNP patients and compared to inferior turbinate tissue from healthy subjects. Tissue localization and expression of both plasmacytoid and myeloid DCs were assayed by means of immunohistochemistry and flow cytometry. Plasmacytoid DCs were also assayed by PCR, and tissue homogenates were assayed for various inflammatory markers. RESULTS: The number of plasmacytoid (pDCs) and myeloid (mDCs) dendritic cells was significantly increased in nasal polyp tissue when compared to non-inflamed nasal mucosa. The number of pDCs, but not mDCs, was down-regulated in more severe cases (nasal polyps with asthma) and varied with the cytokine milieu. The amount of pDCs was significantly decreased in IL5+IFNγ - nasal polyp tissue compared to tissues with high IFNγ levels (IL5+IFNγ+). Furthermore, levels of indoleamine 2,3-dioxygenase were increased in nasal polyp compared to inferior turbinate tissue and correlated negatively with the number of pDCs. CONCLUSIONS: There is an altered balance of pDC and mDC numbers in nasal polyp tissue. pDCs seem to be more susceptible to an inflammatory cytokine milieu and may play a crucial role in disease severity.

Suppression of cytokine release by fluticasone furoate vs. mometasone furoate in human nasal tissue ex-vivo.

BACKGROUND: Topical glucocorticosteroids are the first line therapy for airway inflammation. Modern compounds with higher efficacy have been developed, but head-to-head comparison studies are sparse. OBJECTIVE: To compare the activity of two intranasal glucocorticoids, fluticasone furoate (FF) and mometasone furoate (MF) with respect to the inhibition of T helper (Th)1, Th2 and Th17 cytokine release in airway mucosa. METHODS: We used an ex-vivo human nasal mucosal tissue model and employed pre- and post- Staphylococcus aureus enterotoxin B (SEB)-challenge incubations with various time intervals and drug concentrations to mimic typical clinical situations of preventive or therapeutic use. RESULTS: At a fixed concentration of 10-10 M, FF had significantly higher suppressive effects on interferon (IFN)-γ, interleukin (IL)-2 and IL-17 release, but not IL-5 or tumor necrosis factor (TNF)-α, vs. MF. While the maximal suppressive activity was maintained when FF was added before or after tissue stimulation, the cytokine suppression capacity of MF appeared to be compromised when SEB-induced cell activation preceded the addition of the drug. In a pre-challenge incubation setting with removal of excess drug concentrations, MF approached inhibition of IL-5 and TNF-α after 6 and 24 hours while FF maximally blocked the release of these cytokines right after pre-incubation. Furthermore, FF suppressed a wider range of T helper cytokines compared to MF. CONCLUSION: The study demonstrates the potential of our human mucosal model and shows marked differences in the ability to suppress the release of various cytokines in pre- and post-challenge settings between FF and MF mimicking typical clinical situations of preventive or therapeutic use.

Damage-associated molecular patterns and their receptors in upper airway pathologies.

Inflammation of the nasal (rhinitis) and sinus mucosa (sinusitis) are prevalent medical conditions of the upper airways that are concurrent in many patients; hence the terminology "rhinosinusitis". The disease status is further defined to be "chronic" in case symptoms persist for more than 12 weeks without resolution. A diverse spectrum of external factors including viral and bacterial insults together with epithelial barrier malfunctions could be implicated in the chronicity of the inflammatory responses in chronic rhinosinusitis (CRS). However, despite massive research efforts in an attempt to unveil the pathophysiology, the exact reason for a lack of resolution still remains poorly understood. A novel set of molecules that could be implicated in sustaining the inflammatory reaction may be found within the host itself. Indeed, besides mediators of inflammation originating from outside, some endogenous intracellular and/or extracellular matrix (ECM) components from the host can be released into the extracellular space upon damage induced during the initial inflammatory reaction where they gain functions distinct from those during normal physiology. These "host-self" molecules are known to modulate inflammatory responses under pathological conditions, potentially preventing resolution and contributing to the development of chronic inflammation. These molecules are collectively classified as damage-associated molecular patterns (DAMPs). This review summarizes the current knowledge regarding DAMPs in upper airway pathologies, also covering those that were previously investigated for their intracellular and/or ECM functions often acting as an antimicrobial agent or implicated in tissue/cell homeostasis, and for which their function as a danger signaling molecule was not assessed. It is, however, of importance to assess these molecules again from a point of view as a DAMP in order to further unravel the pathogenesis of CRS.

Sputum IgE and cytokines in asthma: relationship with sputum cellular profile.

BACKGROUND: Local IgE production may play a role in asthma pathogenesis. The aim of the study was to assess sputum total IgE and cytokines in asthmatics according to sputum cellular phenotype. METHODS: We studied 122 subjects including 22 non atopic healthy subjects, 41 eosinophilic (sputum eosinophils ≥3%), 16 neutrophilic (sputum neutrophils >76%) and 43 pauci-granulocytic asthmatics (sputum eosinophils <3% and sputum neutrophils ≤76%) recruited from the asthma clinic at CHU Liege. Sputum supernatant total IgE (tIgE) was measured by ImmunoCAP and sputum supernatant cytokines (IL-4, IL-5, IL-6, IL-10, IL-13, IL-17, IFN-γ and TNF-α) were measured with the Luminex xMAP Technology by using commercially available Fluorokine MAP kits. RESULTS: After concentrating sputum samples, total IgE was detectable in the majority of subjects. Sputum IgE was raised in asthmatics when compared to healthy subjects. Overall, asthmatics did not significantly differ from healthy subjects with respect to cytokine levels. The eosinophilic asthma phenotype, however, was characterised by raised sputum tIgE, IL-5 and IL-13 compared to healthy subjects (p<0.001, p<0.001 and p<0.05 respectively) and pauci-granulocytic asthma (p<0.01, p<0.001 and p<0.05 respectively) and raised IL-5 compared to neutrophilic asthma (p<0.01). When patients were classified according to sputum IgE levels, it appeared that IL-5, IL-6, IL-17 and TNF-α sputum supernatant levels were raised in the "IgE high" asthmatics (IgE ≥0.1 kU/l) when compared to "IgE low" asthmatics (IgE<0.1 kU/l). CONCLUSION: The eosinophilic asthma phenotype was associated with raised sputum IgE and a Th2 cytokine profile. Raised sputum IgE was associated with a heterogeneous cytokine overproduction.

Purinergic signaling in inflammatory cells: P2 receptor expression, functional effects, and modulation of inflammatory responses.

Extracellular ATP and related nucleotides promote a wide range of pathophysiological responses via activation of cell surface purinergic P2 receptors. Almost every cell type expresses P2 receptors and/or exhibit regulated release of ATP. In this review, we focus on the purinergic receptor distribution in inflammatory cells and their implication in diverse immune responses by providing an overview of the current knowledge in the literature related to purinergic signaling in neutrophils, macrophages, dendritic cells, lymphocytes, eosinophils, and mast cells. The pathophysiological role of purinergic signaling in these cells include among others calcium mobilization, actin polymerization, chemotaxis, release of mediators, cell maturation, cytotoxicity, and cell death. We finally discuss the therapeutic potential of P2 receptor subtype selective drugs in inflammatory conditions.

RAGE processing in chronic airway conditions: involvement of Staphylococcus aureus and ECP.

BACKGROUND: The receptor for advanced glycation end products (RAGE) is a multiligand receptor that exists as a membrane-bound (mRAGE) form and a soluble (sRAGE) form. RAGE is reported to play a role in diverse pathologies including lower airway conditions, but the exact mechanism of action remains poorly understood. In the upper airways, the involvement of RAGE remains completely unexplored. OBJECTIVE: To investigate the involvement of RAGE in the human upper airway conditions chronic rhinosinusitis without nasal polyps (CRSsNP) and chronic rhinosinusitis with nasal polyps (CRSwNP). METHODS: Protein levels of sRAGE, mRAGE, IL-5, and eosinophil cationic protein (ECP) were quantitatively assessed in inflamed tissue of CRSsNP and CRSwNP patients. Nasal tissue of subjects without disease served as control. Ex vivo human sinonasal tissue stimulation assays were used to assess the effect of Staphylococcus aureus and ECP on sRAGE processing. RESULTS: sRAGE protein levels were higher in CRSsNP tissue, whereas mRAGE protein levels were lower than in controls. In CRSwNP patients, both tissue sRAGE and mRAGE protein levels were reduced. Low tissue sRAGE protein concentrations were associated with high IL-5 and ECP protein levels. In vitro, S aureus induced the release of sRAGE from the tissue, while ECP was shown to be implicated in the breakdown of free sRAGE. CONCLUSIONS: We demonstrate for the first time that RAGE protein is highly expressed in human upper airways under normal physiology and that it is subject to differential processing in CRSsNP and CRSwNP, identifying S aureus and ECP as novel and crucial players in this process.

A Herbal Composition of Scutellaria baicalensis and Eleutherococcus senticosus Shows Potent Anti-Inflammatory Effects in an Ex Vivo Human Mucosal Tissue Model.

Background. Patients seek an effective alternative to pharmacotherapy including herbal treatment options for allergic rhinitis and rhinosinusitis. Material and Methods. Nasal mucosal tissue was obtained from 12 patients, fragmented, preincubated with tissue culture medium, S. baicalensis and/or E. senticosus and/or vitamin C (each compound 0.2 µg/mL and 2 µg/mL) for 1 hour at 37°C/5% CO2, and stimulated with anti-IgE for 30 minutes and 6 hours to imitate the allergic early and late phases. Furthermore, Staphylococcus aureus superantigen B (SEB) stimulation for 6 hours was used to imitate T-cell activation. Results. The combination of S. baicalensis and E. senticosus had a more potent suppressive effect on the release of PGD2, histamine, and IL-5 than S. baicalensis alone. The combination also resulted in a significant inhibition of SEB-induced cytokines comparable or superior to an established topical corticosteroid, fluticasone propionate. Vitamin C increased ciliary beat frequency, but had no anti-inflammatory effects. Discussion. The combination of S. baicalensis and E. senticosus may be able to significantly block allergic early-and late-phase mediators and substantially suppress the release of proinflammatory, and Th1-, Th2-, and Th17-derived cytokines.

Pathogenesis of chronic rhinosinusitis: inflammation.

Chronic rhinosinusitis (CRS) is a heterogeneous group of inflammatory diseases of the nasal and paranasal cavities either accompanied by polyp formation (CRSwNP) or without polyps (CRSsNP). CRSsNP and CRSwNP are prevalent medical conditions associated with substantial impaired quality of life, reduced workplace productivity, and serious medical treatment costs. Despite recent research evidence that contributes to further unveiling the pathophysiology of these chronic airway conditions, the cause remains poorly understood and appears to be multifactorial. A diverse spectrum of alterations involving histopathology, inflammatory cell and T-cell patterns, remodeling parameters (eg, TGF-ß), eicosanoid and IgE production, microorganisms, and epithelial barrier malfunctions is reported in the search to describe the pathogenesis of this heterogeneous group of upper airway diseases. Furthermore, novel evidence indicates considerable heterogeneity within the CRSwNP subgroup determining the risk of comorbid asthma. The characterization of specific disease subgroups is a challenging scientific and clinical task of utmost importance in the development of diagnostic tools and application of individualized treatments. This review focuses on recent evidence that sheds new light on our current knowledge regarding the inflammatory process of CRS to further unravel its pathogenesis.

Capsaicin-induced vasodilatation in human nasal vasculature is mediated by modulation of cyclooxygenase-2 activity and abrogated by sulprostone.

Extensively based on evidence gained from experimental animal models, the transient receptor potential vanilloid receptor type 1 (TRPV1)-activator capsaicin is regarded as a valuable tool in the research on neurogenic inflammation. Although capsaicin-related drugs gained renewed interest as a therapeutic tool, there is also controversy as whether neurogenic inflammation actually takes place in humans. In this study, we verified the involvement of capsaicin in vascular responses that are regarded to be implicated in the cascade of neurogenic inflammatory mechanisms. By means of ex vivo functional experiments on human nasal mucosal vascular beds, the effect and mechanism of action of capsaicin was assessed in the absence and presence of various agents that interfere with potentially related transduction pathways. Ten micromolars of capsaicin induced vasodilatations that were reduced by the selective EP(1) prostanoid receptor antagonist SC19220 (10 µM) and almost abolished by the selective COX-2 inhibitor NS398 (1 µM) and the EP(1/3) receptor agonist sulprostone (0.1-10 nM), but not affected by the TRPV1-antagonists capsazepine (5 µM), the neurokinin NK(1) receptor antagonist GR20517A (1 µM), and the calcitonin-gene-related peptide (CGRP) receptor antagonist CGRP8-37 (100 nM). Spontaneously released PGE(2) and PGD(2) levels were significantly reduced in the presence of capsaicin. In conclusion, capsaicin-at concentrations clinically applied or under investigation for diverse disease backgrounds-induces a vasodilatory response in human nasal mucosa via a mechanism involving TRPV1-independent reduction of PGE(2) production by modulation of COX-2 enzymatic activity. These vasodilatations can be suppressed by the EP(1/3) receptor agonist sulprostone at subnanomolar concentrations.

Chronic sinusitis and rhinitis: clinical terminology "Chronic Rhinosinusitis" further supported.

BACKGROUND: Chronic rhinosinusitis (CRS) is a heterogeneous group of inflammatory diseases of the nasal and paranasal cavities, either accompanied by polyp formation (CRSwNP) or without polyps (CRSsNP). The etiology and pathophysiology is unknown; some specialists define rhinitis and sinusitis as one clinical entity, whereas others regard both as separate dis-eases. We therefore investigated the immunological background of the chronically inflamed nasal and sinusal mucosa. METHODS: Protein levels of the inflammatory mediators ILl-beta, IL-5, ECP, INF-gamma, and TGF-beta were assessed in ethmoidal mucosal samples from CRSsNP and CRSwNP patients, and compared with the expression profile in nasal inferior turbinate (17) mucosa of the same patient groups. Nasal tissue of patients without disease served as control. RESULTS: In CRSwNP, increased levels of IL-5 and ECP were not only observed in ethmoidal samples, but also in the nasal IT-mucosa. TGF-beta levels were lower in polyps, reaching significance versus ethmoidal mucosa of CRSsNP. In CRSsNP, INF-gamma levels are up-regulated in both ethmoidal and nasal mucosa compared to control tissue. CONCLUSION: On the basis of similar inflammatory mediator profiles, we conclude that rhinitis accompanies chronic sinusitis, supporting the consensus term "rhinosinusitis". On the other hand, CRSsNP and CRSwNP should be regarded as distinct clinical entities.