Spatial expression of two anti-inflammatory mediators, annexin 1 and galectin-1, in nasal polyposis

BACKGROUND: There is renewed interest in the role played by specific counter-regulatory mechanisms to control the inflammatory host response, poorly investigated in human pathology. Here, we monitored the expression of two anti-inflammatory mediators, annexin 1 and galectin-1, and assessed their potential link to glucocorticoids' (GCs) effective control of nasal polyposis (NP). METHODS: Total patterns of mRNA and protein expression were analysed by quantitative real-time PCR (qPCR) and Western blotting analyses, whereas ultrastructural immunocytochemistry was used for spatial localization and quantification of each mediator, focusing on mast cells, eosinophils and epithelial cells. RESULTS: Up-regulation of the annexin 1 gene, and down-regulation of galectin-1 gene, was detected in polypoid tissue compared with nasal mucosa. Patient treatment with betamethasone augmented galectin-1 protein expression in polyps. At the cellular level, control mast cells and eosinophils displayed higher annexin 1 expression, whereas marked galectin-1 immunolabelling was detected in the granule matrix of mast cells. Cells of glandular duct epithelium also displayed expression of both annexin 1 and galectin-1, augmented after treatment. CONCLUSION: Mast cells and epithelial cells appeared to be pivotal cell types involved in the expression of both annexin 1 and galectin-1. It is possible that annexin 1 and galectin-1 could be functionally associated with a specific mechanism in NP and that GC exert at least part of their beneficial effects on the airway mucosa by up-regulating, in a specific cell target fashion, these anti-inflammatory agonists.     

Increased expression and role of thymic stromal lymphopoietin in nasal polyposis

Purpose

Nasal polyposis is a chronic inflammatory disease of the upper airways often associated with asthma and characterized by markedly increased numbers of eosinophils, Th2 type lymphocytes, fibroblasts, goblet cells and mast cells. Previous studies have shown elevated levels of thymic stromal lymphopoietin (TSLP) in atopic diseases like asthma, atopic dermatitis and mainly in animal models of allergic rhinitis (AR). Here, we investigated the expression of TSLP in nasal polyps from atopics and non-atopics in comparison with the nasal mucosa and its potential role in nasal polyposis.

Methods

Messenger RNA expression for TSLP, thymus and activation-regulated chemokine (TARC) and macrophage derived chemokine (MDC) in nasal polyps and nasal mucosa of atopics and non-atopics was analyzed by real time PCR. Immunoreactivity for TSLP in nasal polyps and in the nasal mucosa of patients with AR and non-allergic rhinitis (NAR) was analyzed by immunohistochemistry. Eosinophil counts was analyzed by Wright-Giemsa staining and nasal polyp tissue IgE, by ELISA.

Results

Messenger RNA expression for TSLP,TARC and MDC was markedly higher in nasal polyps as compared to the allergic nasal mucosa. Immunoreactivity for TSLP was detected in epithelial cells, endothelial cells, fibroblasts and inflammatory cells of the nasal mucosa and nasal polyps. The number of TSLP+ cells was significantly greater in the nasal mucosa of AR than NAR patients. The number of TSLP+ cells in nasal polyps from atopics was significantly greater than that of non-atopics and that in the allergic nasal mucosa. The number of TSLP+ cells correlated well with the number of eosinophils and the levels of IgE in nasal polyps.

Conclusions

The high expression of TSLP in nasal polyps and its strong correlation to eosinophils and IgE suggest a potential role for TSLP in the pathogenesis of nasal polyps by regulating the Th2 type and eosinophilic inflammation.     

Galectin-1 and galectin-3 binding pattern expression in renal cell carcinomas.

We studied 2 families of molecules whose role remains uncharacterized or obscure in the progress of renal cell carcinoma (RCC): galectins, a major class of glycoproteins, and the Thomsen-Friedenreich (T) antigen. We characterized the level of expression of galectin-1 and galectin-3 and their respective binding sites in a series of 74 RCCs. We also characterized the level of expression of laminin, a natural ligand for galectins. Finally, we characterized the level of T antigen expression and the T antigen binding sites. All levels of expression were quantitatively determined by using computer-assisted microscopy on immunohistochemically or glycohistochemically stained slides. A small concentration of galectin-1 binding sites or a large concentration heterogeneity of galectin-3 can be associated with unfavorable prognoses for patients with grade II or III RCCs. In contrast, T antigen and T antigen binding sites revealed no change across the 2 RCC groups that exhibited different clinical outcomes. We established discriminant scores that permitted a clear distinction between the 2 RCC groups analyzed. Modifications to the expression of galectin-1 and galectin-3, but not of T antigen, parallel an increase in RCC aggressiveness. Galectins represent a family of molecules with a meaningful role in RCC progression.     

Changes in galectin-7 and cytokeratin-19 expression during the progression of malignancy in thyroid tumors: diagnostic and biological implications.

Galectin-7 is associated with p53-dependent onset of apoptosis and proliferation control/differentiation in keratinocyte development. It is also up-regulated in chemically induced rat mammary carcinogenesis. Because the levels of expression of galectin-7 have never been investigated in thyroid tumors (in contrast to those of galectin-1 and -3 associated with malignancy), we initiated analysis of the expression of galectin-7 in benign and malignant thyroid lesions together with that of cytokeratin-19 (CK19), a marker already demonstrated to be useful in diagnosing this kind of lesion. The immunohistochemical expression levels were quantitatively determined by means of computer-assisted microscopy on a series of 84 thyroid lesions including 10 multinodular goiters, 32 adenomas, and 42 carcinomas. Our data clearly indicate a marked down-regulation of galectin-7 expression in a large proportion of adenomas (including the normomacrofollicular, microfollicular, and trabecular variants) if compared with carcinomas. In accordance with results of previous studies, a marked up-regulation of CK19 expression was observed in the thyroid carcinomas, and this contrasted in particular with the low CK19 expression observed in the microfollicular adenomas. Of importance for diagnostic implications, the combination of these two markers enabled our series of microfollicular adenomas (characterized by low galectin-7 and CK19 expression) to be efficiently distinguished from the encapsulated follicular variant of papillary thyroid carcinomas (high galectin-7 and CK19 expression).     

Regulation of glucocorticoid receptor in nasal polyps by systemic and intranasal glucocorticoids

Background: Poor response of nasal polyps to glucocorticoids (GCs) may be because of abnormal expression of GC receptors (GR) α and β or to downregulation of GRα. We aimed to evaluate the in vivo regulation of GR isoforms in GC‐treated nasal polyps and to assess the relationship between clinical response to GCs and GR levels. Methods: Patients with nasal polyps were randomly (3:1) treated (n = 51) or not (n = 14) with oral prednisone and intranasal budesonide for 2 weeks, plus intranasal budesonide for 10 additional weeks. Nasal symptoms were evaluated. Biopsies were obtained before (w0) and after 2 (w2) and 12 (w12) weeks of treatment, and analysed for their inflammatory content and GR mRNA (10² cDNA copies/μg total RNA) and protein (% immunoreactive inflammatory cells) expression. Healthy nasal mucosa (n = 11) was also investigated. Data are presented as median and 25–75th percentile. Results: At w0, nasal polyps expressed less GRα mRNA (1343;683–2263; P < 0.05) and GR protein (41;29–54; P < 0.05) than nasal mucosa (2474;1346–2933; 60;51–72, respectively). GRβ immunoreactivity was higher in nasal polyps (11;4–19; P < 0.05) than in nasal mucosa (5;2–5). At w2, increased GRα mRNA (2010;1037–2732; P < 0.01) and GR protein (56;27–71; P = 0.056) were found compared with w0 (1177;759–2058; 37;29–55, respectively). At w12, GRα mRNA and GR protein were similar to w0. GRβ expression was unaltered by treatment. Neither GRα nor GRβ correlated with nasal symptoms. GR immunoreactivity negatively correlated with eosinophils (r = ?0.478; P < 0.001). Conclusions: GRα is downregulated in nasal polyps and upregulated by GC treatment. Neither GRα nor GRβ appear to determine the sensitivity to GCs in nasal polyposis.     

Effect of prednisolone on cytokine synthesis in nasal polyps.

To investigate steroid effects on eosinophils and their associated cytokines in nasal polyps, we sampled nasal polyp tissue from 20 subjects during routine surgery. Freshley removed polyps were cut into small pieces and incubated in culture medium for 24 h in different concentrations of prednisolone (10(-2)-10(-6) mol/L). Cell viability was assessed by means of trypan dye exclusion of the supernatants. The number of eosinophils was quantified by means of cytocentrifuge smears stained by May-Giemsa-Grunwald stain. The cytokine protein content of interleukin-5 (IL-5), IL-3, and granulocyte-macrophage colony-stimulating factor (GM-CSF) was measured by ELISA technique in supernatants and in homogenates of nasal polyp tissue. Our results revealed a significant reduction in the number of eosinophils and total number of vital cells at concentrations of 10(-3) and 10(-2) mol/L. GM-CSF and IL-5 protein levels were significantly reduced in supernatants and in homogenates after treatment with prednisolone, whereas IL-3 synthesis was not diminished. Corticosteroid effects known to inhibit synthesis of eosinophil-associated cytokines could be measured in terms of a significant decrease in IL-5 and GM-CSF protein level as well as in a decrease in the number of vital cells.     

Prognostic values of galectin-3 and the macrophage migration inhibitory factor (MIF) in human colorectal cancers.

This study aims to investigate whether the immunohistochemical levels of expression of galectin-3 and the macrophage migration inhibitory factor (MIF) are associated with prognostic values in human colorectal tumors. This was performed on 99 specimens including 69 colorectal tumors (17 Dukes A, 19 Dukes B, 15 Dukes C and 18 metastatic tumors that we labeled as D), 10 hepatic metastases from colorectal cancers and 20 normal specimens (biopsies). The immunohistochemical levels of expression of MIF and galectin-3 were quantified on routine histological slides by means of computer-assisted microscopy. Separate analyses were performed on epithelial and connective tissue. The levels of expression of both MIF and galectin-3 were very significantly higher in epithelial tumor tissue when compared with normal epithelial specimens. A positive and significant correlation between MIF and galectin-3 expression was evidenced in connective tumor tissue, and in particular in the cases associated with short survival periods (less than 5 years). In the case of the Dukes A or B tumors, we established two new prognostic groups (labeled I and II) on the basis of the levels of galectin-3 expression measured in the tumor epithelium. In the case of the Dukes C or D tumors, we established two other prognostic groups (labeled III and IV) on the basis of the levels of MIF expression measured in the connective tissue. Kaplan-Meyer analyses confirmed the additional prognostic values (as compared with conventional clinical staging) given by this new classification (groups I to IV). They show that the Dukes A or B tumors characterized by low levels of galectin-3 expression in the tumor epithelium are associated with significantly better prognoses than those characterized by high levels. In addition, the Dukes C or D tumors characterized by high levels of MIF expression in the connective tumor tissue are associated with significantly better prognoses than those characterized by low levels. In conclusions, MIF and galectin-3 expression levels in colorectal tumors are related to their levels of biological aggressiveness. These markers could be used to identify patients at risk, for whom more aggressive adjuvant therapy seems to be indicated.     

Galectin fingerprinting in tumor diagnosis. Differential expression of galectin-3 and galectin-3 binding sites, but not galectin-1, in benign vs malignant uterine smooth muscle tumors

Cell-matrix interactions are governed by a distinct set of proteins, with 2 nonintegrin laminin-binding proteins, galectin-1 and galectin-3, providing 1 aspect. The expression patterns of laminin and the 2 galectins and galectin binding sites were quantitatively determined by means of computer-assisted microscopy with the aim of differentiating between 16 leiomyomas and 10 leiomyosarcomas of the uterus. Three quantitative variables were computed for each of the 5 histochemical markers: labeling index, which describes the percentage of tissue area specifically stained by a given marker; mean optical density which reflects the concentration of the marker; and concentrational heterogeneity, which characterizes the degree of heterogeneity of the marker distribution in the tumor tissue areas. The results reveal evident differences in the galectin-3-related parameters in the 2 tumors groups. Whereas the concentration of galectin-3 binding sites was significantly (P = .01) weaker in the leiomyosarcomas than in the leiomyomas, the percentages of tumor tissue expressing galectin-3 (P = .02) and its binding sites (P = .002) were significantly higher in the leiomyosarcomas than in the leiomyomas. Although significantly (P = .02) higher, the concentration of laminin was more heterogeneously distributed (P = .01) in the leiomyosarcomas than in the leiomyomas. In contrast, the levels of expression of galectin-1 and its accessible binding sites remained similar for both the leiomyomas and the leiomyosarcomas. Finally we document how the levels of expression of galectin-3 and its binding sites can be of assistance in reliably differentiating leiomyomas from leiomyosarcomas.     

Endothelial L-selectin ligand expression in nasal polyps

Background:  L-selectins on leukocytes and their counter-receptors on endothelial cells have been shown to be involved in leukocyte recruitment in chronic rhinosinusitis without nasal polyps (NP).
Objectives:  The purpose of this study was to evaluate the expression level of functionally active endothelial L-selectin ligands in NP obtained from patients with NP of different etiology [simple NP, antro-choanal polyps (ACP) and cystic fibrosis (CF) NP] and inferior turbinate specimens of healthy controls and to compare these levels to the presence of various leukocyte subsets.
Methods:  Nasal polyp specimens and healthy nasal mucosa specimens were obtained from patients undergoing surgery and were immunohistochemically stained with monoclonal antibodies detecting CD34, sialyl Lewis x (sLe^x) of sulfated extended core 1 lactosamines and various leukocyte subsets.
Results:  All NP are characterized by a decrease in the number of CD34+ vessels. The number of eosinophils and the percentage of vessels expressing endothelial sulfated sLe^x epitopes is upregulated in all groups of simple NP. Tissue eosinophilia is increased in those patients with increased disease severity (acetyl salicylic acid intolerance), but the percentage of endothelial sulfated sLe^x epitopes is not. Results on CF NP are similar to those observed for simple NP. Antro-choanal polyps, on the contrary, are characterized by low numbers of tissue eosinophils and relatively few vessels expressing endothelial sulfated sLe^x epitopes.
Conclusions:  Our results suggest that functionally active L-selectin ligands might play a role in guiding leukocyte traffic into NP in patients with simple NP and CF NP but not ACP.     

Expression of 5-lipoxygenase and cyclooxygenase pathway enzymes in nasal polyps of patients with aspirin-intolerant asthma

In aspirin-intolerant subjects, adverse bronchial and nasal reactions to cyclooxygenase (COX) inhibitors are associated with over-production of cysteinyl-leukotrienes (cys-LTs) generated by the 5-lipoxygenase (5-LO) pathway. In the bronchi of patients with aspirin-intolerant asthma, we previously linked cys-LT over-production and aspirin hyper-reactivity with elevated immunoexpression in eosinophils of the terminal enzyme for cys-LT production, LTC4 synthase. We investigated whether this anomaly also occurs in the nasal airways of these patients. Immunohistochemical expression of 5-LO and COX pathway proteins was quantified in nasal polyps from 12 patients with aspirin-intolerant asthma and 13 with aspirin-tolerant asthma. In the mucosa of polyps from aspirin-intolerant asthmatic patients, cells immunopositive for LTC4 synthase were four-fold more numerous than in aspirin-tolerant asthmatic patients (p=0.04). There were also three-fold more cells expressing 5-LO (p=0.037), with no differences in 5-LO activating protein (FLAP), COX-1 or COX-2. LTC4 synthase-positive cell counts correlated exclusively with mucosal eosinophils (r=0.94, p<0.001, n=25). Co-localisation confirmed that five-fold higher eosinophil counts (p=0.007) accounted for the increased LTC4 synthase expression in polyps from aspirin-intolerant asthmatic patients, with no alterations in mast cells or macrophages. Within the epithelium, increased counts of eosinophils (p=0.006), macrophages (p=0.097), and mast cells (p=0.034) in aspirin-intolerant asthmatic polyps were associated only with 2.5-fold increased 5-LO-positive cells (p<0.05), while the other enzymes were not different. Our results indicate that a marked over-representation of LTC4 synthase in mucosal eosinophils is closely linked to aspirin intolerance in the nasal airway, as in the bronchial airways.     

Distribution Change of Mast Cells in Human Nasal Polyps

Recent studies have shown that mast cells are involved in pathophysiologic processes of chronic inflammation. However, little is known about the distribution of mast cells in nasal polyps, which is a chronic inflammatory disease of the upper airways. Biopsy specimens from patients with nasal polyps (n = 20) and control patients without nasal polyps (n = 8) were included in this study. The distribution of mast cells in nasal polyps was determined by immunohistochemistry. Meanwhile, we detected the expression of chemokines (CCL5, CCL11, CX3CL1, IL‐8, IL‐6) in the epithelial cells of normal nasal mucosa and nasal polyps. In addition, the expression of these chemokines was investigated by western bolting in airway epithelial cells line (A549 cells) under inflammatory condition. Mast cells migrated toward intraepithelium in nasal polyps and the expression of chemokines (CCL5, CCL11, CX3CL1, IL‐8) was up‐regulated in the epithelial cells of nasal polyps compared with normal nasal mucosa. The expression of chemokines was also up‐regulated in A549 cells after Lipopolysaccharide (LPS)‐treatment for 3 hr and 6 hr. Our findings showed that mast cells migrate toward intraepithelium in nasal polyps and the overexpression of chemokines (CCL5, CCL11, CX3CL1, IL‐8) suggested that they might be responsible for mast cells migration. It implies that mast cell play potential roles in the development of nasal polyps. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.     

Immunolocalization of CD34 in nasal polyposis. Effect of topical corticosteroids

Airway inflammation in patients with nasal polyps is characterized by the increased presence of eosinophils, the numbers of which are reduced after treatment with topical corticosteroids. Because eosinophilic responses in the airways are in part due to eosinophil progenitor differentiation, we hypothesized that CD34, a cell surface, sialomucinlike glycoprotein that specifically marks hemopoietic progenitors and endothelium, would be expressed in nasal polyp tissue. We sought to identify CD34(+) leukocytes or endothelial cells in nasal polyps. We also investigated the effect of the topical corticosteroid budesonide on the numbers of CD34(+) cells and vessels in nasal polyps. To accomplish this, we performed immunostaining for CD34 protein in tissue sections of nasal polyps from topical steroid-treated and -untreated groups of patients, as well as from one patient before and after systemic corticosteroid therapy. We also examined myeloid colony formation by isolated polyp mononuclear cells, and performed flow cytometry to detect the presence of CD34(+)/CD45(+) cells within these isolated populations. We also examined the in vitro effects of steroids on human umbilical vein endothelial cell (HUVEC) expression of CD34. We detected CD34-immunoreactive mononuclear cells and blood vessels in the lamina propria of all nasal polyps. CD34(+) mononuclear cells resembled immature hemopoietic cells morphologically. Mononuclear cell fractions from polyps contained myeloid colony-forming cells and cells bearing CD45, a pan-leukocyte marker, as well as CD34, and gated as true hemopoietic blast cells. The numbers of CD34(+) cells and CD34(+) vessels in steroid-treated nasal polyps were significantly higher than in steroid-untreated nasal polyps (15.67 +/- 2.08 cells/10 hpf, versus 5.33 +/- 1.36 cells/10 hpf, P = 0.002; 101.25 +/- 6.24 vessels/0.5 mm2 of lamina propria, versus 57.22 +/- 8.00 vessels/0.5 mm2 of lamina propria, P = 0.0008, respectively). A similar upregulation of CD34 immunostaining, especially for mononuclear cells, was observed in one patient after systemic corticosteroid therapy. Steroid treatment in vitro of HUVECs did not result in enhanced CD34 expression. Both CD34(+)/CD45(+) mononuclear cells and CD34(+) endothelial cells are present within nasal polyps, with higher numbers in patients who have received topical corticosteroid treatment. Because enhancement of CD34 expression was not seen in cultured umbilical vein endothelial cells treated in vitro with corticosteroid, the findings of the study suggest that in nasal polyp tissue, steroids enhance numbers of CD34(+) progenitors and endothelial cells via indirect mechanisms.     

The pathogenesis of nasal mucosa polyps, studied with histochemical detection of phenol oxidase (E. C. 1.14.18.1)

There were investigated polyps of the nasal mucous membrane with the histological diagnosis: allergic-hyperergic, lympho-plasma cellular, and angioma-like. Using the phenol oxidase reaction, it was possible to integrate the allergic-hyperergic and the lympho-plasma cellular polyps into the pathologic course of cell mediated immunological defence reactions in which the eosinophilic granulocytes have an essential role. The eosinophils are typical for the immunological character of the defense reaction.     

Role of prostaglandin D2 and E2 terminal synthases in chronic rhinosinusitis

BACKGROUND: Prostaglandin (PG)D(2) and E(2), two major cyclooxygenase (COX) products, are generated by PGD(2) synthase (PGDS) and PGE(2) synthase (PGES), respectively, and appear to mediate airway inflammation. OBJECTIVE: We sought to determine the role of PGDS and PGES in the pathophysiology of chronic rhinosinusitis (CRS). METHODS: The study examined the expression of PGDS and PGES in nasal polyps of 22 CRS patients. As controls, uncinate process mucosae were obtained from 12 CRS patients not having nasal polyps and five subjects without sinusitis. Immunohistochemistry and quantitative real-time PCR were used to evaluate the expression. RESULTS: Both PGDS and PGES were detected in nasal polyps by immunohistochemistry. Significantly greater levels of PGDS mRNA and lesser levels of PGES mRNA were observed in the nasal polyps as compared with uncinate process mucosae, and an inverse correlation between PGDS and PGES expression was observed. Levels of PGDS mRNA in nasal polyps were positively correlated with degree of infiltration by EG2+ eosinophils, whereas the levels of PGES were inversely correlated. Significantly increased levels of PGDS and conversely decreased levels of PGES were observed in asthmatics as compared with non-asthmatics. In addition, PGDS and PGES levels were positively and inversely correlated with the radiological severity of sinusitis, respectively. CONCLUSIONS: These results suggest that PGDS and PGES display an opposite and important role in the pathophysiology of CRS such as polyp formation, and more specifically, a biased expression of these synthases might contribute to the development of CRS by affecting eosinophilic inflammation.     

Evaluating budesonide efficacy in nasal polyposis and predicting the resistance to treatment

Background Cell resistance to glucocorticoids is a major problem in the treatment of nasal polyposis (NP). Objectives The objectives of this study were to observe the effect of budesonide on the expression of IL‐1β, TNF‐α, granulocyte macrophage‐colony stimulating factor, intercellular adhesion molecule (ICAM)‐1, basic fibroblast growth factor, eotaxin‐2, glucocorticoid receptor (GR)‐α, GR‐β, c‐Fos and p65 in nasal polyps and to correlate their expression to clinical response. Methods Biopsies from nasal polyps were obtained from 20 patients before and after treatment with topical budesonide. Clinical response to treatment was monitored by a questionnaire and nasal endoscopy. The mRNA levels of the studied genes were measured by real‐time quantitative (RQ)‐PCR. Results There was a significant decrease in the expression of TNF‐α (P<0.05), eotaxin‐2 (P<0.05) and p65 (P<0.05) in NP after treatment. Poor responders to glucocorticoids showed higher expression of IL‐1β (3.74 vs. 0.14; P<0.005), ICAM‐1 (1.91 vs. 0.29; P<0.05) and p65 (0.70 vs. 0.16; P<0.05) before treatment. Following treatment, IL‐1β (4.18 vs. 0.42; P<0.005) and GR‐β (0.95 vs. 0.28; P<0.05) mRNA expression was higher in this group. Conclusion Topical budesonide reduced the expression of TNF‐α, eotaxin‐2 and p65. Poor responders to topical budesonide exhibit higher levels of IL‐1β, ICAM‐1 and nuclear factor (NF)‐κB at diagnosis and higher expression of both IL‐1β and GR‐β after treatment. These results emphasize the anti‐inflammatory action of topical budesonide at the molecular level and its importance in the treatment of NP. Nevertheless, IL‐1β, ICAM‐1 and NF‐κB may be associated with primary resistance to glucocorticoids in NP, whereas higher expression of GR‐β in poor responders only after glucocorticoid treatment may represent a secondary drug resistance mechanism in this disease.     

Effects of topical anti-inflammatory drugs on eosinophil survival primed by epithelial cells. Additive effect of glucocorticoids and nedocromil sodium

Background Eosinophil infiltration is a hallmark of the inflammatory response in rhinitis and in nasal polypcsis. Objective We studied the effect of steroids and nedocromil sodium on eosinophil survival primed by epithelial cells from healthy (nasal mucosa) and inflamed (nasal polyp) respiratory tissue. Methods Blood eosinophils were incubated with increasing concentrations (10^-11 10^-5 M) of topical steroids (fiuticasone propionate, budesonide, triamcinolone acetonide and beclomethasone dipropionate) and/or nedocromil sodium prior to the addition of human epithelial cell conditioned media (HECM), eosinophil viability was measured and IC₅₀ for each drug was calculated. Results All four steroids and nedocromil sodium caused a dose-related inhibition of HECM-induced eosinophil survival. The IC₅₀ of steroids were lower in eosinophils primed by mucosa HECM than on those primed by polyp HECM (fluticasone, 4nM vs 114nM: budesonide, 21 nM vs 280 nM; triamcinolone, 7 nM vs 853 nM; and beclomethasone, 171 nM vs 181 nM). The combined inhibitory effect of 10^-7M budesonide plus 10^-5M nedocromil (43.8 ± 10.8%, P < 0.03) was significantly higher than budesonide (28.5 ± 9.2%) or nedocromil (16.7 ± 5.4%) alone and close to 10^-5M budesonide (52.3 ± 11%). No differences were found in cytokine (IL-8, IL-6, GM-CSF, TNFα, IL-lβ and RANTES) concentrations between HECM from mucosa and polyps. Conclusion These results suggest that topical anti-inflammatory drugs may diminish airway eosinophilic infiltration by decreasing eosinophil viability, that nasal polyp epithelial cell secretions may induce steroid resistance in eosinophils, and that nedocromil sodium has additive effects with steroids.     

Relation of epidermal growth factor receptor expression to goblet cell hyperplasia in nasal polyps

BACKGROUND: Because the epidermal growth factor receptor (EGFR) system regulates mucin production in airway epithelium, we hypothesized a role for this system in mucus hypersecretion that occurs in nasal polyposis. OBJECTIVE: We examined the relationship between goblet cell hyperplasia, EGFR expression, and inflammatory mediators produced by eosinophils and neutrophils in nasal polyp tissues. METHODS: Nasal polyp tissue samples from 8 patients and nasal turbinate biopsy specimens from 6 normal control subjects were examined for alcian blue/PAS staining, mucin MUC5AC (MUC5AC), and EGFR immunoreactivity and EGFR gene expression (in situ hybridization). We also examined the role of eosinophils and neutrophils in goblet cell hyperplasia. RESULTS: In control nasal mucosa alcian blue/periodic acid-Schiff- and MUC5AC-stained areas were 18.40% +/- 1.31% and 21.89% +/- 1.43%, respectively. In polyps the alcian blue/periodic acid-Schiff- and MUC5AC-stained areas were 51.30% +/- 5.85% and 52.07% +/- 6.58%, which was significantly larger than that found in control subjects (each comparison, P <.01). Four of 6 control specimens expressed EGFR messenger RNA and protein weakly in the epithelium. In polyps 4 of 8 specimens expressed EGFR gene and EGFR protein strongly; the EGFR-stained area was greater in hyperplastic than in pseudostratified epithelium. TNF-alpha immunoreactivity, expressed in eosinophils, was increased in EGFR-positive polyps compared with EGFR-negative polyps, suggesting a role for TNF-alpha in EGFR expression. Neutrophils were increased in the epithelium of EGFR-positive compared with EGFR-negative polyps, suggesting a role for these cells in mucin expression and in goblet cell degranulation. CONCLUSION: These data suggest a role for EGFR cascade in the regulation of goblet cell mucins in nasal polyps. Proof of concept will require clinical studies using selective EGFR inhibitors.