Search

Background: Chronic rhinosinusitis with nasal polyps (CRSwNP) is a chronic inflammatory disease of the upper airways frequently associated with asthma. Bacterial infection is a feature of CRSwNP that can aggravate the disease and the response to glucocorticoid treatment., Objective: We examined whether the bacterial product lipopolysaccharide (LPS) reduces glucocorticoid receptor (GR) function in control nasal mucosa (NM) fibroblasts and in nasal polyp (NP) fibroblasts from patients with CRSwNP and asthma., Methods: NP (n = 12) and NM fibroblasts (n = 10) were in vitro pre-incubated with LPS (24 hours) prior to the addition of dexamethasone. Cytokine/chemokine secretion was measured by ELISA and Cytometric Bead Array. GRα, GRβ, mitogen-activated protein-kinase phosphatase-1 (MKP-1) and glucocorticoid-induced leucine zipper (GILZ) expression was measured by RT-PCR and immunoblotting, GRα nuclear translocation by immunocytochemistry, and GRβ localization by immunoblotting. The role of MKP-1 and GILZ on dexamethasone-mediated cytokine inhibition was analyzed by small interfering RNA silencing., Results: Pre-incubation of nasal fibroblasts with LPS enhanced the secretion of IL-6, CXCL8, RANTES, and GM-CSF induced by FBS. FBS-induced CXCL8 secretion was higher in NP than in NM fibroblasts. LPS effects on IL-6 and CXCL8 were mediated via activation of p38α/β MAPK and IKK/NF-κB pathways. Additionally, LPS pre-incubation: 1) reduced dexamethasone's capacity to inhibit FBS-induced IL-6, CXCL8 and RANTES, 2) reduced dexamethasone-induced GRα nuclear translocation (only in NM fibroblasts), 3) did not alter GRα/GRβ expression, 4) decreased GILZ expression, and 5) did not affect dexamethasone's capacity to induce MKP-1 and GILZ expression. MKP-1 knockdown reduced dexamethasone's capacity to suppress FBS-induced CXCL8 release., Conclusion: The bacterial product LPS negatively affects GR function in control NM and NP fibroblasts by interfering with the capacity of the activated receptor to inhibit the production of pro-inflammatory mediators. This study contributes to the understanding of how bacterial infection of the upper airways may limit the efficacy of glucocorticoid treatment.

Objectives/hypothesis: To investigate the effect of oral plus intranasal corticosteroid (CS) treatment on nasal polyp (NP) mucosa remodeling from patients with severe chronic rhinosinusitis with nasal polyps (CRSwNP)., Study Design: Case series, retrospective study., Methods: Patients (n = 18) with severe CRSwNP were treated with oral prednisone for 2 weeks and intranasal budesonide for 12 weeks. NP biopsies were obtained from patients biopsies before (w0) and after 2 weeks (w2) and 12 weeks (w12) of CS treatment. Matrix metalloprotease 1 (MMP-1), MMP-2, MMP-7, MMP-9, and tissue inhibitor of metalloprotease type 1 (TIMP-1) expression was evaluated by immunohistochemistry in cell and tissue structures. Epithelial damage, eosinophil infiltration, and collagen content were also examined in NP tissues before and after CS treatment., Results: Compared to w0: 1) oral plus intranasal CS significantly (P < .01) increased presence of submucosal glands at w2, decreased epithelial cell hyperplasia at w12, and decreased tissue eosinophilia at w2 and w12; 2) CS treatment significantly (P < .05) increased immunoreactivity for MMP-1 and MMP-2 in the epithelium at w2, but decreased immunoreactivity for MMP-9 in the epithelium at w2 and w12; 3) at w12, CS significantly (P < .05) reduced MMP-9 immunoreactive positivity and intensity in the extracellular matrix, while increasing total collagen amount in the extracellular matrix; and 4) CS treatment significantly (P < .01) reduced the number of eosinophils and their MMP and TIMP-1 immunoreactive expression., Conclusions: CS treatment modulates NP mucosa remodeling, particularly by promoting epithelial repair, regulating tissue remodeling markers, increasing total collagen content, and reducing tissue eosinophil infiltration., Level of Evidence: 4, (© 2015 The American Laryngological, Rhinological and Otological Society, Inc.)

Background: Primary human airway epithelial cells cultured in an air-liquid interface (ALI) develop a well-differentiated epithelium. However, neither characterization of mucociliar differentiation overtime nor the inflammatory function of reconstituted nasal polyp (NP) epithelia have been described., Objectives: 1st) To develop and characterize the mucociliar differentiation overtime of human epithelial cells of chronic rhinosinusitis with nasal polyps (CRSwNP) in ALI culture system; 2nd) To corroborate that 3D in vitro model of NP reconstituted epithelium maintains, compared to control nasal mucosa (NM), an inflammatory function., Methods: Epithelial cells were obtained from 9 NP and 7 control NM, and differentiated in ALI culture for 28 days. Mucociliary differentiation was characterized at different times (0, 7, 14, 21, and 28 days) using ultrastructure analysis by electron microscopy; ΔNp63 (basal stem/progenitor cell), β-tubulin IV (cilia), and MUC5AC (goblet cell) expression by immunocytochemistry; and mucous (MUC5AC, MUC5B) and serous (Lactoferrin) secretion by ELISA. Inflammatory function of ALI cultures (at days 0, 14, and 28) through cytokine (IL-8, IL-1β, IL-6, IL-10, TNF-α, and IL-12p70) and chemokine (RANTES, MIG, MCP-1, IP-10, eotaxin-1, and GM-CSF) production was analysed by CBA (Cytometric Bead Array)., Results: In both NP and control NM ALI cultures, pseudostratified epithelium with ciliated, mucus-secreting, and basal cells were observed by electron microscopy at days 14 and 28. Displaying epithelial cell re-differentation, β-tubulin IV and MUC5AC positive cells increased, while ΔNp63 positive cells decreased overtime. No significant differences were found overtime in MUC5AC, MUC5B, and lactoferrin secretions between both ALI cultures. IL-8 and GM-CSF were significantly increased in NP compared to control NM regenerated epithelia., Conclusion: Reconstituted epithelia from human NP epithelial cells cultured in ALI system provides a 3D in vitro model that could be useful both for studying the role of epithelium in CRSwNP while developing new therapeutic strategies, including cell therapy, for CRSwNP.

Background: Fluticasone furoate (FF) is an intranasal corticosteroid indicated for the treatment of allergic rhinitis (AR). However, the anti-inflammatory effects of FF in the nasal mucosa have yet to be investigated thoroughly. The aim of this study was to investigate the effect of FF on eosinophil survival and cytokine secretion from nasal mucosa epithelial cells., Methods: Epithelial cells obtained from nasal mucosa were stimulated with 10% fetal bovine serum (FBS) in the presence of FF (from 10(-12) to 10(-7)M) for 6-24 h. Cytokine [granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin (IL)-6 and IL-8] concentrations in supernatants were measured by ELISA. Peripheral blood eosinophils were incubated for 4 days with epithelial cell secretions in the presence or absence of FF (from 10(-12) to 10(-7)M) and survival was assessed by Trypan blue dye exclusion. Results are expressed as medians of the minimum effective concentration and IC values., Results: FBS stimulated the secretion of GM-CSF, IL-6 and IL-8. FF significantly inhibited GM-CSF (up to 10(-10)M, IC25 = 12.6 pM), IL-6 (up to 10(-10)M, IC25 = 65.8 pM) and IL-8 (up to 10(-11)M, IC25 = 8.6 pM) secretion induced by FBS (n = 8). Epithelial cell secretions induced eosinophil survival from day 1 to day 4 (n = 6). This effect was significantly inhibited by FF (up to 10(-12)M) at day 3 (IC50 = 3.22 nM) and day 4 (IC50 = 1.29 nM)., Conclusions: The results obtained in this in vitro model suggest that FF may reduce upper airway eosinophilic inflammation through decreasing cytokine secretion from epithelial cells and reducing eosinophil survival., (© 2014 S. Karger AG, Basel.)

Background: Endoscopic transsphenoidal surgery is currently the optimal treatment for skull base tumors. This study was designed to assess patient's sinonasal symptoms and quality of life (QoL) after resection of pituitary adenoma or skull base tumors using vascularized septal flap (VSF) reconstruction., Methods: Patients with pituitary adenoma underwent the transnasal transsphenoidal endoscopic approach (TTEA; n = 38), and patients with other benign parasellar tumors underwent the expanded endonasal approach (EEA; n = 17) with VSF. Assessment of sinonasal symptoms and QoL by the 36-item Short-Form (SF-36) and the 31-item Rhinosinusitis Outcome Measure (RSOM-31) were performed before and 3 months after surgery., Results: At baseline, the total seven-sinonasal symptom score (T7SSS) was similar between both groups. After surgery, T7SSS significantly increased in EEA but not in TTEA patients. EEA patients reported more smell loss (40.1 ± 26.2; p < 0.05) and posterior nasal discharge (49.3 ± 30.1; p < 0.05) than TTEA patients (21.6 ± 30.9 and 22.5 ± 27.5, respectively). At baseline, both groups had poorer SF-36 compared with the general population. TTEA patients had poorer QoL (on general health, vitality, and mental health) than EEA patients. After surgery, TTEA patients showed impaired physical role and bodily pain compared with baseline, and EEA patients showed impaired physical role and mental health. At baseline, RSOM scores were similar in TTEA and EEA groups. After surgery, EEA but not TTEA patients reported poorer nasal and general symptoms., Conclusion: The EEA with VSF produces more sinonasal symptoms than pituitary surgery, surgery for skull base and pituitary tumors has negative impact on QoL, and functioning tumors have no further negative effect on sinonasal symptoms and QoL.

Background and Objective: Anomalies in the regulation of cyclooxygenase (COX)-1 and -2 have been described in nasal polyps of aspirin-induced asthma (AIA). Whether these anomalies are specific to nasal polyps or affect all the nasal mucosa (NM) of upper airways is still unclear. The objective of this study was to compare the COX pathway in NM of AIA patients with the NM of control subjects., Methods: Fibroblasts were isolated from NM of five AIA patients (AIA-NM) and five control subjects (control-NM). Cells were treated with 10 ng/mL interleukin (IL)-1β for up to 72 h. Prostaglandin E2 (PGE2 ) production was measured by enzyme-linked immunosorbent assay (ELISA), expression of COX-1 protein by Western blot and COX-2 protein by ELISA, Western blot and immunofluorescence techniques., Results: IL-1β increased PGE2 production and COX-1 protein expression in control-NM fibroblasts, but no changes were found in AIA-NM. IL-1β provoked a significant time-dependent increase in COX-2 protein expression in control-NM fibroblasts but had a very mild effect on COX-2 protein expression in AIA-NM., Conclusions: Our data suggest that abnormalities in the COX pathway are not a phenomenon exclusive to nasal-polyp mucosa as they are also present in all the NM of AIA patients. These anomalies may be involved in the pathogenesis of airway inflammation and non-steroidal anti-inflammatory drug intolerance in asthma patients with chronic rhinosinusitis and nasal polyposis., (© 2013 The Authors. Respirology © 2013 Asian Pacific Society of Respirology.)

Proteasome inhibitors, used in cancer treatment for their proapoptotic effects, have anti-inflammatory and antifibrotic effects on animal models of various inflammatory and fibrotic diseases. Their effects in cells from patients affected by either inflammatory or fibrotic diseases have been poorly investigated. Nasal polyposis is a chronic inflammatory disease of the sinus mucosa characterized by tissue inflammation and remodeling. We tested the hypothesis that proteasome inhibition of nasal polyp fibroblasts might reduce their proliferation and inflammatory and fibrotic response. Accordingly, we investigated the effect of the proteasome inhibitor Z-Leu-Leu-Leu-B(OH)(2) (MG262) on cell viability and proliferation and on the production of collagen and inflammatory cytokines in nasal polyp and nasal mucosa fibroblasts obtained from surgery specimens. MG262 reduced the viability of nasal mucosa and polyp fibroblasts concentration- and time-dependently, with marked effects after 48 h of treatment. The proteasome inhibitor bortezomib provoked a similar effect. MG262-induced cell death involved loss of mitochondrial membrane potential, caspase-3 and poly(ADP-ribose) polymerase activation, induction of c-Jun phosphorylation, and mitogen-activated protein kinase phosphatase-1 expression. Low concentrations of MG262 provoked growth arrest, inhibited DNA replication and retinoblastoma phosphorylation, and increased expression of the cell cycle inhibitors p21 and p27. MG262 concentration-dependently inhibited basal and transforming growth factor-β-induced collagen mRNA expression and interleukin (IL)-1β-induced production of IL-6, IL-8, monocyte chemoattractant protein-1, regulated on activation normal T cell expressed and secreted, and granulocyte/macrophage colony-stimulating factor in both fibroblast types. MG262 inhibited IL-1β/tumor necrosis factor-α-induced activation of nuclear factor-κB. We conclude that noncytotoxic treatment with MG262 reduces the proliferative, fibrotic, and inflammatory response of nasal fibroblasts, whereas high MG262 concentrations induce apoptosis.

Background: In vitro culture of nasal polyp cells is frequently used in the investigation of inflammatory mechanisms and effect of treatments in nasal polyposis. Research outcomes may, however, be influenced by the culture methodology used., Methods: Nasal polyp and nasal mucosa in vitro fibroblast cultures were pre-treated with foetal bovine serum (FBS)-free culture medium or medium supplemented with either FBS or charcoal-stripped (cs) FBS. Cells were then stimulated with FBS or csFBS, with or without different doses of dexamethasone for 4 and 24h. IL-6, IL-8, GM-CSF and VEGF release and cell viability were measured., Results: The highest cytokine levels were found in growth-arrested cells stimulated with 10% FBS. csFBS poorly stimulated cytokine release. Nasal polyp released larger IL-8 amounts than nasal mucosa fibroblasts. Dexamethasone decreased cytokine production dose- and time-dependently in both nasal mucosa and nasal polyp fibroblasts. The IC25 of IL-8 inhibition by dexamethasone was higher in nasal polyp than in nasal mucosa fibroblasts. Cell viability did not differ among treatments., Conclusions: Cytokine production by in vitro cultured nasal fibroblasts is affected by the culture conditions used and is inhibited by dexamethasone in both fibroblast types. Our results highlight the importance of culture methodology on nasal polyp research outcomes.

Background: Although antihistamines and topical corticosteroids are used in combination to treat allergic rhinitis, their additive effect has not been yet demonstrated. The aim was investigate the antiinflammatory additive effect of mometasone and desloratadine on cytokine and sICAM-1 secretion by epithelial cells, and on eosinophil survival stimulated by human epithelial cells secretions from nasal mucosa and polyps., Methods: Epithelial cells obtained from nasal mucosa or polyps were stimulated with 10% fetal bovine serum in presence of mometasone (10(-11) M-10(-5) M) with/without desloratadine (10(-5) M). Cytokine and sICAM-1 concentrations in supernatants were measured by ELISA. Peripheral blood eosinophils were incubated during 4 days with epithelial cell secretions with (10(-11) M-10(-5) M) and/or desloratadine (10(-5) M) and survival assessed by Trypan blue. Results are expressed as percentage (mean ± SEM) compared to control., Results: Fetal bovine serum stimulated IL-6, IL-8, GM-CSF and sICAM-1 secretion. In mucosa and polyp epithelial cells, mometasone inhibited this induced secretion while desloratadine inhibited IL-6 and IL-8. The combination of 10(-5) M desloratadine and 10(-9) M mometasone reduced IL-6 secretion (48 ± 11%, p < 0.05) greater extent than mometasone alone (68 ± 10%) compared to control (100%). Epithelial cell secretions induced eosinophil survival from day 1 to 4, this effect being inhibited by mometasone. At day 4, the combination of mometasone (10(-11) M) and desloratadine (10(-5) M) provoked an increased inhibition of eosinophil survival induced by cell secretions (27 ± 5%, p < 0.01) than mometasone (44 ± 7%) or desloratadine (46 ± 7%) alone., Conclusions: These results suggest that the combination of desloratadine and mometasone furoate have a greater antinflammatory effect in an in vitro model of eosinophil inflammation than those drugs administered alone.

Background: Treatment with glucocorticoids (GCs) is the cornerstone of nasal polyp (NP) therapy, but some patients respond poorly to them. Fibroblasts are involved in both inflammation and remodelling of NP. We aimed to evaluate whether NP fibroblasts are less sensitive to GCs' anti-proliferative and anti-inflammatory effects, compared to nasal mucosa (NM) fibroblasts., Methods: Fibroblasts were obtained from NP (n = 8) from asthmatic patients undergoing endoscopic surgery and NM (n = 8) from patients undergoing nasal corrective surgery. Fibroblasts were stimulated with DMEM at 0.5% or 5% FBS, or TGF-β (5 ng/ml), with or without dexamethasone (10(-11) to 10(-5)M) for different times. Cell proliferation, collagen mRNA expression and IL-6 and IL-8 release were measured., Results: After 3-days, dexamethasone dose-dependently inhibited proliferation of NM (p < 0.001) but not that of NP fibroblasts. Dexamethasone (10(-6)M) reduced by 25% the proliferation of NM fibroblasts. Dexamethasone also inhibited proliferation of NM (p < 0.01) but not that of NP fibroblasts at 5-days. TGF-β induced collagen-1α1, -1α2, and -3α1 mRNA levels in both NM and NP fibroblasts (p < 0.05), and dexamethasone did not alter TGF-β-induced collagen mRNA levels in either fibroblast type at 24 h. Dexamethasone dose-dependently decreased (p < 0.05) FBS-induced IL-6 and IL-8 release in both NM and NP fibroblasts at 4 h, although at 10(-8)M, dexamethasone inhibited cytokine production in NM (p < 0.05) but not in NP fibroblasts., Conclusions: This impaired sensitivity of nasal polyp fibroblasts to in vitro glucocorticoid effects concurs in part with the poor clinical response that these nasal polyp patients show to glucocorticoid treatment., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

Background: The Platelet-Activating Factor (PAF)/receptor (PAFR) system is involved in asthma and allergic rhinitis; however, its role in chronic rhinosinusitis (CRS) is still unclear. This study aimed to assess the expression of PAFR and the concentration of Lyso-PAF isoforms in the nasal polyps (NP) of patients suffering from CRS with/without comorbidities such as asthma and NSAID-exacerbated respiratory disease (N-ERD) compared to healthy nasal mucosa (NM) from control subjects. Methods: NM (n = 8) and NP tissues were obtained from patients undergoing surgery for septal deviation/turbinate hypertrophy or endoscopic sinus surgery, respectively. Three phenotypes were studied: CRSwNP with no asthma (n = 6), CRSwNP with non-steroidal anti-inflammatory drug (NSAID)-tolerant asthma (n = 6), and CRSwNP with NSAID-exacerbated respiratory disease (n = 6). PAFR protein and mRNA were assessed via immunochemistry, immunofluorescence, Western blot, and real-time quantitative PCR. Lyso-PAF isoforms (C16, C18, and C18:1) were quantified via mass spectrometry. Results: PAFR protein was expressed in the NM and NP, concretely in epithelial cells and submucosal glands. Compared to NM, PAFR mRNA expression was higher in all NP phenotypes (p < 0.05) while all Lyso-PAF isoform concentrations were higher in the NP from asthmatic patients (p < 0.05). Lyso-PAF C16 and C18 concentrations were higher in the NP from asthmatic patients than in the NP from patients without asthma. Conclusions: The PAF/PAFR system could play a pathophysiological role in CRSwNP pathogenesis. [ABSTRACT FROM AUTHOR]

Background: Human adult basal stem/progenitor cells (BSCs) obtained from chronic rhinosinusitis with nasal polyps (CRSwNP) when differentiated in an air‐liquid interface (ALI) usually provide a pseudostratified airway epithelium with similar abnormalities than original in vivo phenotype. However, the intrinsic mechanisms regulating this complex process are not well defined and their understanding could offer potential new therapies for CRSwNP (incurable disease). Methods: We performed a transcriptome‐wide analysis during in vitro mucociliary differentiation of human adult BSCs from CRSwNP, compared to those isolated from control nasal mucosa (control‐NM), in order to identify which key mRNA and microRNAs are regulating this complex process in pathological and healthy conditions. Results: A number of genes, miRs, biological processes, and pathways were identified during mucociliary differentiation of both CRSwNP and control‐NM epithelia, and notably, we have demonstrated for the first time that genetic transcriptional program responsible of ciliogenesis and cilia function is significantly impaired in CRSwNP epithelium, presumably produced by an altered expression of microRNAs, particularly of those miRs belonging to mir‐34 and mi‐449 families. Conclusions: This study provides for the first time a novel insight into the molecular basis of sinonasal mucociliary differentiation, demonstrating that transcriptome related to ciliogenesis and cilia function is significantly impaired during differentiation of CRSwNP epithelium due to an altered expression of microRNAs. [ABSTRACT FROM AUTHOR]

Background: Primary human airway epithelial cells cultured in an air-liquid interface (ALI) develop a well-differentiated epithelium. However, neither characterization of mucociliar differentiation overtime nor the inflammatory function of reconstituted nasal polyp (NP) epithelia have been described. Objectives: 1st) To develop and characterize the mucociliar differentiation overtime of human epithelial cells of chronic rhinosinusitis with nasal polyps (CRSwNP) in ALI culture system; 2nd) To corroborate that 3D in vitro model of NP reconstituted epithelium maintains, compared to control nasal mucosa (NM), an inflammatory function. Methods: Epithelial cells were obtained from 9 NP and 7 control NM, and differentiated in ALI culture for 28 days. Mucociliary differentiation was characterized at different times (0, 7, 14, 21, and 28 days) using ultrastructure analysis by electron microscopy; ΔNp63 (basal stem/progenitor cell), β-tubulin IV (cilia), and MUC5AC (goblet cell) expression by immunocytochemistry; and mucous (MUC5AC, MUC5B) and serous (Lactoferrin) secretion by ELISA. Inflammatory function of ALI cultures (at days 0, 14, and 28) through cytokine (IL-8, IL-1β, IL-6, IL-10, TNF-α, and IL-12p70) and chemokine (RANTES, MIG, MCP-1, IP-10, eotaxin-1, and GM-CSF) production was analysed by CBA (Cytometric Bead Array). Results: In both NP and control NM ALI cultures, pseudostratified epithelium with ciliated, mucus-secreting, and basal cells were observed by electron microscopy at days 14 and 28. Displaying epithelial cell re-differentation, β-tubulin IV and MUC5AC positive cells increased, while ΔNp63 positive cells decreased overtime. No significant differences were found overtime in MUC5AC, MUC5B, and lactoferrin secretions between both ALI cultures. IL-8 and GM-CSF were significantly increased in NP compared to control NM regenerated epithelia. Conclusion: Reconstituted epithelia from human NP epithelial cells cultured in ALI system provides a 3D in vitro model that could be useful both for studying the role of epithelium in CRSwNP while developing new therapeutic strategies, including cell therapy, for CRSwNP. [ABSTRACT FROM AUTHOR]

Background and objective Anomalies in the regulation of cyclooxygenase ( COX)-1 and -2 have been described in nasal polyps of aspirin-induced asthma ( AIA). Whether these anomalies are specific to nasal polyps or affect all the nasal mucosa ( NM) of upper airways is still unclear. The objective of this study was to compare the COX pathway in NM of AIA patients with the NM of control subjects. Methods Fibroblasts were isolated from NM of five AIA patients ( AIA-NM) and five control subjects (control- NM). Cells were treated with 10 ng/mL interleukin ( IL)-1β for up to 72 h. Prostaglandin E2 ( PGE2) production was measured by enzyme-linked immunosorbent assay ( ELISA), expression of COX-1 protein by Western blot and COX-2 protein by ELISA, Western blot and immunofluorescence techniques. Results IL-1β increased PGE2 production and COX-1 protein expression in control- NM fibroblasts, but no changes were found in AIA-NM. IL-1β provoked a significant time-dependent increase in COX-2 protein expression in control- NM fibroblasts but had a very mild effect on COX-2 protein expression in AIA-NM. Conclusions Our data suggest that abnormalities in the COX pathway are not a phenomenon exclusive to nasal-polyp mucosa as they are also present in all the NM of AIA patients. These anomalies may be involved in the pathogenesis of airway inflammation and non-steroidal anti-inflammatory drug intolerance in asthma patients with chronic rhinosinusitis and nasal polyposis. [ABSTRACT FROM AUTHOR]

Presents three cases of mucosa-associated lymphoid tissue lymphoma in the cavum. Common location of the tumors; Medical history of the patients; Treatment procedures.

Background We hypothesized that the 2 reported alterations in aspirin-exacerbated respiratory disease (AERD), reduced expression/production of COX-2/prostaglandin (PG) E 2 and diminished expression of E-prostanoid (EP) 2 receptor, are closely linked. Objective We sought to determine the mechanisms involved in the altered regulation of the COX pathway in patients with AERD. Methods Fibroblasts were obtained from nasal mucosa; samples of control subjects (NM-C, n = 8) and from nasal polyps from patients with aspirin-exacerbated respiratory disease (NP-AERD, n = 8). Expression of the autocrine loop components regulating PGE 2 production and signaling, namely IL-1 type I receptor (IL-1RI), COX-2, microsomal prostaglandin E synthase 1 (mPGES-1), and EP receptors, was assessed at baseline and after stimulation with IL-1β, PGE 2 , and specific EP receptor agonists. Results Compared with NM-C fibroblasts, basal expression levels of IL-1RI and EP 2 receptor were lower in NP-AERD fibroblasts. IL-1β–induced IL-1RI, COX-2, and mPGES-1 expression levels were also lower in these cells. Levels of IL-1RI positively correlated with COX-2 and mPGES-1 expression in both NM-C and NP-AERD fibroblasts. Incubation with either exogenous PGE 2 or selective EP 2 agonist significantly increased expression of IL-1RI in NM-C fibroblasts and had hardly any effect on NP-AERD fibroblasts. Alterations in IL-1RI, COX-2, and mPGES-1 expression that were found in NP-AERD fibroblasts were corrected when EP 2 receptor expression was normalized by transfection of NP-AERD fibroblasts. Conclusion Altered expression of EP 2 in patients with AERD contributes to deficient induction of IL-1RI, reducing the capacity of IL-1β to increase COX-2 and mPGES-1 expression, which results in low PGE 2 production. This impairment in the generation of PGE 2 subsequently reduces its ability to induce IL-1RI. [ABSTRACT FROM AUTHOR]

Background: Researchers have debated whether regulation of the COX enzymes (COX-1 and COX-2), which mediate production of prostaglandins (PGs), affects the pathogenesis of nasal polyps (NPs) and aspirin-intolerant asthma (AIA). Objective: We investigated the roles of PGE2, COX-1 and COX-2, and PGE2 receptors in the development of NPs and AIA by measuring their expression in fibroblasts derived from nasal mucosa (NM) and NPs. Methods: Fibroblasts were isolated from the NM of subjects without asthma who had septal deviation, turbinate hypertrophy, or both (control subjects, n = 7); NPs of aspirin-tolerant nonasthmatic patients (n = 7); and NPs of patients with asthma who were intolerant of aspirin (n = 7). Polyp samples were collected during endoscopic surgery. Cultures were stimulated with IL-1β (10 ng/mL) for 72 hours. We used ELISA, immunoblotting, and immunofluorescence analyses to measure secretion of PGE2, expression of COX-1 and COX-2, and expression of the PGE2 receptors EP1 to EP4. Results: Compared with NM from control subjects, PGE2 concentrations were significantly lower in IL-1β–stimulated fibroblasts from patients with NPs who were tolerant to aspirin and even lower in polyps from patients with AIA. Similarly, IL-1β exposure induced the expression of COX-1 and COX-2 in fibroblasts from NM of control subjects, had only moderate effects on fibroblasts from NPs of aspirin-tolerant nonasthmatic patients, and almost no effect on fibroblasts from NPs of patients with AIA. IL-1β also induced expression of EP2 in fibroblasts from control NM but not in fibroblasts from NPs of aspirin-tolerant nonasthmatic patients or those with AIA. Conclusion: Alterations in the COX pathway (ie, reduced production of PGE2 and lack of upregulation of COX-1, COX-2, and EP2 under conditions of inflammation) are associated with NPs in patients with or without AIA. [ABSTRACT FROM AUTHOR]