Low E-prostanoid 2 receptor levels and deficient induction of the IL-1ß/IL-1 type I receptor/COX-2 pathway: Vicious circle in patients with aspirin-exacerbated respiratory disease.

BACKGROUND: We hypothesized that the 2 reported alterations in aspirin-exacerbated respiratory disease (AERD), reduced expression/production of COX-2/prostaglandin (PG) E2 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 PGE2 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-1ß, PGE2, and specific EP receptor agonists. RESULTS: Compared with NM-C fibroblasts, basal expression levels of IL-1RI and EP2 receptor were lower in NP-AERD fibroblasts. IL-1ß-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 PGE2 or selective EP2 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 EP2 receptor expression was normalized by transfection of NP-AERD fibroblasts. CONCLUSION: Altered expression of EP2 in patients with AERD contributes to deficient induction of IL-1RI, reducing the capacity of IL-1ß to increase COX-2 and mPGES-1 expression, which results in low PGE2 production. This impairment in the generation of PGE2 subsequently reduces its ability to induce IL-1RI.

Clinical and biological markers of difficult-to-treat severe chronic rhinosinusitis.

Chronic rhinosinusitis (CRS) is a chronic inflammatory disease of the upper airways of which two major phenotypes exist, CRS without nasal polyps (CRSsNP) and CRS with nasal polyps (CRSwNP). Some patients with CRS have suboptimal response to current guideline treatments. These patients remain severe and uncontrolled by treatment and have a poor quality of life. It is highly important to identify both clinical and biological markers, so-called biomarkers, in this subset of patients. The presence of nasal polyps and comorbidity with asthma and with aspirin-exacerbated respiratory disease (AERD) are the most common clinical traits that have been associated to difficult-to-treat severe CRS. In addition to clinical traits, numerous biological markers, with known etiopathogenic roles in CRS, have been associated to difficult-to-treat or recalcitrant CRS. This review summarizes the existing knowledge of the clinical and biological markers associated to difficult-to-treat or uncontrolled severe CRS.

Fluticasone furoate inhibits cytokine secretion from nasal epithelial cells and reduces eosinophil survival in an in vitro model of eosinophilic inflammation.

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.

Low prostaglandin E2 and cyclooxygenase expression in nasal mucosa fibroblasts of aspirin-intolerant asthmatics.

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)-1ß 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-1ß increased PGE2 production and COX-1 protein expression in control-NM fibroblasts, but no changes were found in AIA-NM. IL-1ß 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.

Proteasome inhibition reduces proliferation, collagen expression, and inflammatory cytokine production in nasal mucosa and polyp fibroblasts.

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-ß-induced collagen mRNA expression and interleukin (IL)-1ß-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-1ß/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.

Reduced expression of COXs and production of prostaglandin E(2) in patients with nasal polyps with or without aspirin-intolerant asthma.

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 PGE(2), COX-1 and COX-2, and PGE(2) 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-1ß (10 ng/mL) for 72 hours. We used ELISA, immunoblotting, and immunofluorescence analyses to measure secretion of PGE(2), expression of COX-1 and COX-2, and expression of the PGE(2) receptors EP1 to EP4. RESULTS: Compared with NM from control subjects, PGE(2) concentrations were significantly lower in IL-1ß-stimulated fibroblasts from patients with NPs who were tolerant to aspirin and even lower in polyps from patients with AIA. Similarly, IL-1ß 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-1ß 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 PGE(2) 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.

Mometasone and desloratadine additive effect on eosinophil survival and cytokine secretion from epithelial cells.

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.

Impact of cell culture methods on the outcomes of the in vitro inflammatory response in nasal polyps.

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.

Correction to: Benefits and harm of systemic steroids for short- and long-term use in rhinitis and rhinosinusitis: an EAACI position paper.

[This corrects the article DOI: 10.1186/s13601-019-0303-6.].

Benefits and harm of systemic steroids for short- and long-term use in rhinitis and rhinosinusitis: an EAACI position paper.

Because of the inflammatory mechanisms of most chronic upper airway diseases such as rhinitis and chronic rhinosinusitis, systemic steroids have been used for their treatment for decades. However, it has been very well documented that-potentially severe-side-effects can occur with the accumulation of systemic steroid courses over the years. A consensus document summarizing the benefits of systemic steroids for each upper airway disease type, as well as highlighting the potential harms of this treatment is currently lacking. Therefore, a panel of international experts in the field of Rhinology reviewed the available literature with the aim of providing recommendations for the use of systemic steroids in treating upper airway disease.

An intranasal selective antisense oligonucleotide impairs lung cyclooxygenase-2 production and improves inflammation, but worsens airway function, in house dust mite sensitive mice.

BACKGROUND: Despite its reported pro-inflammatory activity, cyclooxygenase (COX)-2 has been proposed to play a protective role in asthma. Accordingly, COX-2 might be down-regulated in the airway cells of asthmatics. This, together with results of experiments to assess the impact of COX-2 blockade in ovalbumin (OVA)-sensitized mice in vivo, led us to propose a novel experimental approach using house dust mite (HDM)-sensitized mice in which we mimicked altered regulation of COX-2. METHODS: Allergic inflammation was induced in BALBc mice by intranasal exposure to HDM for 10 consecutive days. This model reproduces spontaneous exposure to aeroallergens by asthmatic patients. In order to impair, but not fully block, COX-2 production in the airways, some of the animals received an intranasal antisense oligonucleotide. Lung COX-2 expression and activity were measured along with bronchovascular inflammation, airway reactivity, and prostaglandin production. RESULTS: We observed impaired COX-2 mRNA and protein expression in the lung tissue of selective oligonucleotide-treated sensitized mice. This was accompanied by diminished production of mPGE synthase and PGE2 in the airways. In sensitized mice, the oligonucleotide induced increased airway hyperreactivity (AHR) to methacholine, but a substantially reduced bronchovascular inflammation. Finally, mRNA levels of hPGD synthase remained unchanged. CONCLUSION: Intranasal antisense therapy against COX-2 in vivo mimicked the reported impairment of COX-2 regulation in the airway cells of asthmatic patients. This strategy revealed an unexpected novel dual effect: inflammation was improved but AHR worsened. This approach will provide insights into the differential regulation of inflammation and lung function in asthma, and will help identify pharmacological targets within the COX-2/PG system.

Relevance of COX-2 gene expression in dementia with lewy bodies associated with Alzheimer pathology.

The aim of the present study was to investigate whether cyclooxygenase-2 (COX-2) expression is involved in the pathogenesis of neurodegeneration in dementia with Lewy bodies (DLB) by measuring COX-2 mRNA and protein expression in frontal cortex and substantia nigra pars compacta of DLB and control human brains. DLB cases were classified as pure form or common form according to the absence or the presence of Alzheimer pathology including neurofibrillary tangles and amyloid deposits by Braak staging. Using Western Blot and Real-time Polymerase chain reaction (PCR) analysis, we have shown that cortical COX-2 protein levels were decreased in DLB cases (P < 0.01). However, no differences in nigral COX-2 mRNA expression were observed between control and DLB cases. In conclusion, the present results suggest that in DLB nigral COX-2 mRNA expression does not correlate with dopaminergic neurodegeneration and that the slight changes observed in the common type are probably due to the concomitant AD pathology.

Superior effect of MP-AzeFlu than azelastine or fluticasone propionate alone on reducing inflammatory markers.

BACKGROUND: MP-AzeFlu, intranasal formulation of azelastine hydrochloride (AZE) and fluticasone propionate (FP), is superior to AZE or FP alone for treatment of allergic rhinitis (AR). However, the precise anti-inflammatory mechanism of action of MP-AzeFlu has not been characterized. OBJECTIVE: To investigate the anti-inflammatory effects of MP-AzeFlu compared with AZE or FP alone in an established in vitro model of eosinophilic inflammation. METHODS: Nasal mucosal epithelial cells and peripheral blood eosinophils were obtained from human volunteers. Epithelial cells were stimulated with 10% fetal bovine serum (FBS) in the presence of MP-AzeFlu, AZE, or FP (1:102 to 1:105 dilution). Concentrations of interleukin (IL)-6, IL-8, and granulocyte-macrophage colony-stimulating factor (GM-CSF) were measured by ELISA. Eosinophils were incubated in 10% human epithelial cell-conditioned medium (HECM) and survival assessed by trypan blue dye exclusion. Results are expressed as mean ± SEM percentage secretion/survival compared with FBS/HECM (respectively). RESULTS: FP and MP-AzeFlu (all dilutions) and AZE (1:102) significantly reduced IL-6 secretion and eosinophil survival compared with positive controls. At 1:102 dilution, IL-6 secretion was significantly lower with MP-AzeFlu (38.3 ± 4.2%, compared with FBS = 100%) than with AZE (76.1 ± 4.9%) or FP (53.0 ± 4.9%). At 1:102 dilution, eosinophil survival was significantly lower with MP-AzeFlu at day 3 (17.5 ± 3.0%) and day 4 (2.4 ± 1.4%, compared with HECM = 100%) than with AZE (day 3: 75.2 ± 7.2%; day 4: 44.0 ± 9.7%) or FP (day 3: 38.5 ± 3.5%; day 4: 14.6 ± 4.0%). CONCLUSION: Greater reductions in cytokine secretion and eosinophil survival observed with MP-AzeFlu in vitro may underlie MP-AzeFlu's superior clinical efficacy vs. AZE or FP alone observed in AR patients.

A short course of oral prednisone followed by intranasal budesonide is an effective treatment of severe nasal polyps.

BACKGROUND: Nasal polyposis is an inflammatory disease of unknown etiology. This study aimed to evaluate the effect of a short course of oral prednisone followed by intranasal budesonide on nasal symptoms, polyp size, nasal flow, and computed tomography scan. METHODS: Eighty-four patients with severe nasal polyps were included. After a steroid washout period, patients were randomized into two groups: group A (n = 63) received oral prednisone for 2 weeks and group B (n = 21) did not receive any steroid treatment. Patients from group A received intranasal budesonide for 12 weeks. RESULTS: Atopy was positive in 36.8% of patients. Blood eosinophilia was higher in asthmatic (7.2 +/- 0.7%, P < .05) than in nonasthmatic (3.0 +/- 0.4%) patients. Asthmatic patients showed higher scores on nasal obstruction and loss of smell than nonasthmatics. Oral steroids caused a significant improvement in all nasal symptoms and improved polyp size (2.1 +/- 0.1, P < .05) and nasal flow (560 +/- 35 cm/s, P < .05) compared with nontreated patients (2.8 +/- 0.1 and 270 +/- 34 cm/s, respectively). Intranasal budesonide maintained the improvement on nasal symptoms, polyp size, and nasal flow. Steroid treatment reduced the computed tomography scan score (15.4 +/- 1, P < .05) compared with before treatment (18.2 +/- 0.8). CONCLUSION: A short course of oral steroids improved all nasal symptoms, polyp size, and nasal flow, whereas intranasal steroid maintain this effect.

Severe nasal polyposis and its impact on quality of life. The effect of a short course of oral steroids followed by long-term intranasal steroid treatment.

OBJECTIVES: Nasal polyposis is not a life-threatening disorder but has a great impact on the quality of life. Steroids constitute the first line of treatment of nasal polyps. The aims of this study were to evaluate the quality of life in nasal polyp patients after: (1) a short course of oral steroids; and (2) a long-term treatment with intranasal steroids. METHODS: Patients with severe nasal polyps received either oral prednisone (n = 60) or no steroid treatment (control group, n = 18) for 2 weeks. Patients treated with steroids were also followed-up and evaluated after 12, 24, and 48 additional weeks with intranasal budesonide treatment. RESULTS: Patients with nasal polyps showed worse scores on all SF-36 domains, except for physical functioning, compared to the Spanish general population. After two weeks, patients treated with oral prednisone demonstrated a significant improvement (p < 0.05) in all impaired QoL domains compared to both control group and baseline. The mental component summary (51.0 +/- 1.2, p < 0.05) and physical component summary (51.0 +/- 0.9, p < 0.05) were improved compared to both control group and baseline. The improvement of all SF-36 domains was sustained by intranasal budesonida (p < 0.05) after 12, 24, and 48 weeks. Nasal obstruction, sense of smell, and polyp size also improved after both the oral short course and the intranasal long-term steroids treatment (p < 0.05). CONCLUSION: These results suggest that the treatment with a short-course of oral steroids improves the quality of life of patients with severe nasal polyps and that this effect is maintained by a long-term treatment with intranasal steroids.

Corticosteroid treatment regulates mucosal remodeling in chronic rhinosinusitis with nasal polyps.

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

Effect of lipopolysaccharide on glucocorticoid receptor function in control nasal mucosa fibroblasts and in fibroblasts from patients with chronic rhinosinusitis with nasal polyps and asthma.

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, GRß, 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 GRß 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/ß 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/GRß 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.

Cyclooxygenase-2 is up-regulated in lung parenchyma of chronic obstructive pulmonary disease and down-regulated in idiopathic pulmonary fibrosis.

BACKGROUND AND AIM OF THE WORK: In vitro studies have suggested that fibroblasts from idiopathic pulmonary fibrosis (IPF) may have an impaired induction of cyclooxygenase (Cox)-2. We have investigated Cox-1 and Cox-2 expression in lung tissue from IPF. METHODS: Cox-1 and Cox-2 expression were determined using RT-competitive PCR and immunohistochemistry in pulmonary biopsies from IPF (n = 22), chronic obstructive pulmonary disease (COPD) (n = 13), and lung tissue from subjects undergoing pleurodesis for spontaneous pneumothorax (control group, n = 17). RESULTS: Immunohistochemical analysis showed that the score of Cox-2 positive cells was higher in COPD (1 +/- 0) with respect to fibrosis (0.37 +/- 0.1, p < 0.05) and controls (0.57 +/- 0.2). There were no differences between fibrosis and controls in Cox-2 positive cells. The expression of Cox-2 mRNA was significantly higher in COPD (3.26 +/- 0.72 x 10(6) molecules cDNA/microg total RNA) in comparison to IPF (0.57 +/- 0.17) and controls (0.54 +/- 0.16) (p < 0.001). After IL-1beta stimulation (1-10 ng/ml) Cox-2 mRNA basal expression increased significantly in controls (from 35 +/- 12 to 94 +/- 4 x10(6) molecules cDNA/microg total RNA, p < 0.01) and in COPD (from 38 +/- 8 to 92 +/- 3, p < 0.01). In contrast, no significant changes in Cox-2 mRNA expression were found in IPF (from 30 +/- 12 to 43 +/- 16). CONCLUSIONS: Our results suggest that differences in Cox-2 expression may play a role in the regulation of inflammatory responses in lung diseases. Excessive activity is associated with the development of chronic obstructive lung disease, while a limited activation following pro-inflammatory stimulation might contribute to fibrogenic responses.

Expression of the glucocorticoid receptor alpha and beta isoforms in human nasal mucosa and polyp epithelial cells.

The lower sensitivity of the inflamed nasal mucosa to glucocorticoids might be related to an increased expression of the glucocorticoid receptor (GR) beta isoform. We investigated GRalpha and GRbeta mRNA expression in epithelial cells from nasal mucosa and nasal polyps. GRalpha mRNA was at least 1000 times more expressed than GRbeta mRNA in both tissues. GRbeta expression (mean+/-SEM of 10(3) cDNA copies/microg of total RNA) was higher in nasal polyps (1.15+/-0.19; n=27; P<0.01) than in nasal mucosa (0.62+/-0.10; n=32). Nasal polyps with > 3% of inflammatory cells had higher GRbeta levels (1.40+/-0.29; n=16) than both nasal mucosa (P<0.01) and polyps with < or = 3% of inflammatory cells (0.80+/-0.18; n=11; P<0.05). No difference in GRbeta expression was found between nasal mucosa and polyps with < or = 3% of inflammatory cells. GRbeta expression correlated with the inflammatory cell number, especially with mast cells (r=0.50, P<0.0001). There was no difference in GRalpha mRNA expression between nasal mucosa and nasal polyps. In summary, GRalpha is far more expressed than GRbeta in both tissues. The increased expression of GRbeta may be related to the presence of inflammatory cells.