Expression Profile of Immune-Associated Genes in Nasal Polyps

Gene-environment interactions between ERCC2, ERCC3, XRCC1 and cadmium exposure in nasal polyposis disease

Gene-environment interactions have long been known to play an important role in complex disease aetiology, such as nasal polyposis (NP). The present study supports the concept that DNA repair gene polymorphisms play critical roles in modifying individual susceptibility to environmental diseases. In fact, we investigated the role of polymorphisms in DNA repair genes and cadmium as risk factors for Tunisian patients with NP. To the best of our knowledge, this is the first report on the impact of combined effects of cadmium and ERCC3 7122 A>G (rs4150407), ERCC2 Lys751Gln (rs13181) and XRCC1 Arg399Gln (rs25487) genes in the susceptibility to NP disease. Significant associations between the risk of developing NP disease and ERCC2 [odds ratio (OR) = 2.0, 95 % confidence interval (CI) = 1.1-3.7, p = 0.023] and ERCC3 (OR = 2.2, 95 % CI = 1.2-4.1, p = 0.013) genotypes polymorphisms were observed. Blood concentrations of Cd in NP patients (2.2 μg/L) were significantly higher than those of controls (0.5 μg/L). A significant interaction between ERCC3 (7122 A>G) polymorphism and blood-Cd levels (for the median of blood-Cd levels: OR = 3.8, 95 % CI = 1.3-10.8, p = 0.014 and for the 75th percentiles of blood-Cd levels: OR = 2.7, 95 % CI = 1.1-7.2, p = 0.041) was found in association with the risk of NP disease. In addition, when we stratified ERCC2, ERCC3 and XRCC1 polymorphism genotypes by the median and 75th percentiles of blood-Cd levels, we found also significant interactions between ERCC2 (Lys751Gln) and ERCC3 (7122 A>G) genotypes polymorphism and this metal in association with NP disease. However, no interaction was found between XRCC1 (Arg399Gln) polymorphism genotypes and Cd in association with NP disease.

Distinct characteristics of nasal polyps with and without eosinophilia

Introduction

Eosinophilic and noneosinophilic Nasal polyps (NPs) are different subtypes of NPs and require different treatment methods.

Objective

To compare the histologic characteristics, mRNA and protein expression between Nasal Polyps with and without eosinophilia.

Methods

NPs tissues were obtained from eighty-six NPs patients during surgery. Eosinophilic and noneosinophilic NPs were distinguished according to immunochemical results of the specimen. The histological, mRNA and protein expression features were compared between the two groups.

Results

In eosinophilic NPs, we observed a significantly higher GATA-3, IL-5, IL-4, IL-13 mRNA and protein expression. In noneosinophilic NPs, IL-17, IL-23 and RORc mRNA and protein expression were increased. Immunohistochemistry tests showed, more mast cells and less neutrophils in eosinophilic NPs compared with noneosinophilic NPs. Eosinophilic NPs patient presented more severe symptom scores when compared to noneosinophilic NPs.

Conclusion

We demonstrate for the first time that Th2 is the predominant reaction in eosinophilic NPs while Th17 is the predominant reaction in noneosinophilic NPs. Our study may provide new treatment strategy for NPs.

Autophagy is deficient in nasal polyps: implications for the pathogenesis of the disease

BACKGROUND

Nasal polyposis is characterized by persistent inflammation but the pathogenesis is complex and still debatable. Autophagy has been associated with many human health problems including chronic inflammatory airway diseases. Whether autophagy plays a role in nasal polyps and could be a therapeutic target is completely unknown.

METHODS

We studied light chain 3 (LC3) protein expression, a common indication of autophagy, in fresh tissue specimens of 5 nasal polyps and 6 normal nasal mucosa by Western blot analysis. The results were also confirmed by immunohistochemistry (IHC) using additional 25 paraffin-embedded nasal tissue sections. Finally the autophagic activity was validated in nasal polyp-derived fibroblasts by evaluating the number of green fluorescent protein (GFP)-labeled LC3 puncta.

RESULTS

The expression of LC3 was dramatically decreased in all 5 nasal polyp tissues. In contrast, protein kinase B-mechanistic target of rapamycin (Akt-mTOR) signaling, an established negative regulator of autophagy, was significantly activated in these tissues. Immunohistochemical results further demonstrated a negative correlation between autophagy and nasal polyps (p < 0.05). GFP-LC3 puncta formation, an alternative indicator of autophagy, was also diminished in nasal polyp-derived fibroblasts (p < 0.01).

CONCLUSION

Autophagy is deficient presumably due to suppression by high Akt-mTOR activity in nasal polyps, which may provide a molecular basis for future mechanistic study of the disease.

An update on the pathogenesis of the upper airways in aspirin-exacerbated respiratory disease

PURPOSE OF REVIEW

The key features of aspirin-exacerbated respiratory diseases (AERDs) include chronic, severe asthma and a high prevalence (60-80%) of chronic rhinosinusitis with nasal polyps, all of which are exacerbated by exposure to aspirin and other NSAIDs. Although the pathogenic mechanisms of AERD are not completely understood, repeated instances have shown intense eosinophilic infiltrations of upper and lower airway mucosa, and dysregulation of arachidonate metabolisms. Here, recent updates on the pathogenic mechanisms of chronic rhinosinusitis with nasal polyps in aspirin-exacerbated respiratory diseases are summarized.

RECENT FINDINGS

Intense eosinophilic infiltration is closely related to the elevated production of cytokines and chemokines such as IL-5 and eotaxin. The response of local immunoglobulin E to staphylococcal enterotoxins contributes to eosinophilic inflammation in nasal polyp tissue. Other characteristics include the overproduction of cysteinyl leukotrienes and increased expression of cysteinyl leukotriene receptor-1, reduced production of prostaglandin E2, and the down-regulation of cyclooxygenase-2 and E-prostanoid receptor subtype-2. A recent gene expression profiling study has also suggested that periostin is the most up-regulated gene in the nasal polyp tissue of AERD patients.

SUMMARY

Chronic rhinosinusitis with nasal polyps is a major comorbid condition of AERD patients that is closely associated with severe asthmatic symptoms. Significant pathologic findings in nasal polyp tissues include intense eosinophilic inflammation, which is caused by elevated production of eosinophil-related cytokines and chemokines, specific immunoglobulin E responses to staphylococcal enterotoxins, and altered arachidonic acid metabolism. This could affect the current treatments and methodologies that are used to control asthma, leading to a more severe and intractable AERD phenotype.

Expression of protease-activated receptors in allergic fungal rhinosinusitis

BACKGROUND

The etiology of the intense inflammatory response showed by patients with allergic fungal rhinosinusitis (AFRS) remains a mystery. Potential sources of this inflammation may include fungal proteases. Protease-activated receptors (PARs) are components of the innate immune response that are modulated by proteolytic activity and are involved in potentiating T helper 2 (Th2) responses. The objective of the study was to determine whether there is differential expression of PARs in patients with AFRS compared to controls.

METHODS

The study was designed as a comparison of gene expression profiles in patients with AFRS vs diseased and nondiseased controls. Twenty-five patients were enrolled. Patients with AFRS (n = 15) were compared to nondiseased controls (n = 5) undergoing minimally invasive pituitary surgery (MIPS) and patients with chronic rhinosinusitis with nasal polyps (CRSwNP, n = 5) undergoing functional endoscopic sinus surgery (FESS). Ethmoid mucosa RNA was hybridized to 4 × 44 K microarray chips. Four gene probes (PAR1, PAR2, PAR3, and PAR4) were used to assess for differential expression. A linear-mixed model was used to account for some patients having multiple samples. Significance level was determined at p < 0.05.

RESULTS

Of the 4 probes, only PAR3 showed statistically significant differential expression between AFRS and nondiseased control samples (p = 0.03) as well as a 2.21-fold change. No additional statistical difference in PAR expression among the comparison groups was noted.

CONCLUSION

PARs have been shown to enhance production of inflammatory cytokines and potentiate Th2 responses. In this initial report, patients with AFRS have a significantly increased expression of PAR3 compared to nondiseased controls.

Staphylococcal enterotoxin B induced expression of IL-17A in nasal epithelial cells and its association with pathogenesis of nasal polyposis

Interleukin (IL)-17A is a highly inflammatory cytokine and is known to be produced by Th17 cells. The importance of IL-17A expression in nasal epithelial cells is not well understood. The goal of this study is to explore the expression of IL-17A in nasal epithelial cells in vivo and in vitro. IL-17A and staphylococcal enterotoxin B (SEB) were detected by immunofluorescence (IF) in nasal epithelial cells of control mucosa (n = 10) and nasal polyps (n = 20). Expression of IL-17A, RORC, IL-6, and TGF-β1 was also measured by RT-PCR in the tissue of control nasal mucosa (n = 10) and nasal polyps (n = 20). IL-17A expression was evaluated in the human nasal epithelial cells after SEB stimulation. Finally, IL-17A expression was demonstrated by immunohistochemistry and IF following intranasal SEB instillation in mice. Expression of IL-17A in nasal epithelial cells was higher in nasal polyps compared to control mucosa. There was a significant correlation between IL-17A and SEB detection in nasal polyps using IF. SEB increased IL-17A expression in human nasal epithelial cells, and in epithelial cells of SEB instilled mice. In conclusion, SEB exposure of nasal epithelial cells induces the enhanced expression of IL-17A. SEB may be involved in pathogenesis of nasal polyps by enhancing IL-17A expression in epithelial cells in nasal polyps.

Interleukin-17A contributes to the expression of serum amyloid A in chronic rhinosinusitis with nasal polyps

The expression and regulation of serum amyloid A (SAA) in patients with chronic rhinosinusitis with nasal polyps (CRSwNP) have not been well documented. This study enrolled 24 CRSwNP patients and 19 controls to evaluate the expression of SAA in polyp tissues in Chinese adult patients and investigate underlying mechanism. The levels of SAA and interleukin (IL)-17A and myeloperoxidase (MPO) in nasal tissues were detected using quantitative reverse transcription polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. In addition, the mRNA expression of SAA was examined in cultured polyp epithelial cells (PECs) in the presence of various cytokines (IFN-γ, IL-4, IL-5 and IL-17A) using qRT-PCR, and the role of extracellular signal-related kinase (ERK) signalling in SAA expression was evaluated by western blot analysis. We found the levels of SAA, IL-17A and MPO were significantly upregulated in polyp tissues compared with the controls (p < 0.05), and significant correlations between SAA and IL-17A mRNA levels, as well as between SAA and MPO protein levels, were observed in polyp tissues (p < 0.05). In the in vitro culture system, IL-17A was found to significantly increase SAA mRNA expression in PECs via ERK signaling pathway, in a time- and dose-dependent manner (p < 0.05). Our results suggested a regulatory mechanism underlying excessive SAA production in polyp tissues, which might gain more insights into the pathophysiology of CRSwNP in Chinese adult patients.

The characterization of IL-17A expression in patients with chronic rhinosinusitis with nasal polyps

BACKGROUND

Interleukin (IL)-17A, mainly produced by Th17 cells, was previously described as an inflammatory cytokine that induces a profile of proinflammatory cytokines, chemokines, and metalloproteinases. Recent studies have revealed that IL-17 is correlated with inflammatory lung disorders by triggering an accumulation of neutrophils. More recently, we have shown that the expression of IL-17 may be involved in the development of nasal polyps (NPs). Here, we describe the characterization of IL-17 expression in patients with chronic rhinosinusitis with nasal polyps (CRSwNPs) from northeast China.

METHODS

Histopathological observations and immunohistochemical (IHC) staining for IL-17, IL-17RD, myeloperoxidase, and CD68 were performed on 52 specimens (42 NPs and 10 specimens of middle turbinate as normal control). Double IHC staining was performed to determine which cells expressed IL-17. The serum expression levels of IL-17 were determined by ELISA and the mRNA expression of IL-17 and Th17 cells transcription factor retinoid acid-related orphan receptor C (RORc) was determined by real-time quantitative polymerase chain reaction.

RESULTS

42.9% of CRSwNP specimens presented eosinophilic inflammation; 35.7% of CRSwNP specimens presented neutrophilic inflammation. Relatively higher mRNA expression levels of IL-17 and RORc were seen in CRSwNPs compared with the controls. A marked increase of IL-17 and IL-17RD proteins (p < 0.01) were seen in CRSwNP group. The expression levels of IL-17 and RORc did not differ between eosinophilic and noneosinophilic CRSwNPs (p > 0.05). However, high expression levels of IL-17RD were seen in noneosinophilic CRSwNPs compared with eosinophilic CRSwNPs (p < 0.05). The serum expression of IL-17 in CRSwNP patients was similar to healthy controls. The IL-17 expressing cells mainly were the macrophages as shown by double IHC staining.

CONCLUSION

Chinese CRSwNP patients showed an enhanced Th17 response regardless of eosinophilic or noneosinophilic inflammation. IL-17 may be involved in the development of NPs through its local immune modulation.

Topographic gene expression in the sinonasal cavity of patients with chronic sinusitis with polyps

OBJECTIVE

To determine whether variations in gene expression exist at multiple subsites along the sinonasal tract in patients with chronic sinusitis with polyps and in healthy controls.

STUDY DESIGN

Prospective, controlled study.

SETTING

Academic medical center.

SUBJECTS AND METHODS

Tissue expression levels of 5 genes, previously found to be characteristic of ethmoid polyps, were measured using real-time quantitative polymerase chain reaction in 100 sinonasal tissue samples. Specimens harvested from 5 regions--the ethmoid sinus, septum, inferior turbinate, middle turbinate, and lateral nasal wall--in 10 patients with chronic sinusitis and ethmoid polyps were compared to tissue from similar regions in 10 control patients without sinusitis. Western blot analysis was performed to validate differential gene expression at the protein level.

RESULTS

Gene expression levels of ethmoid polyps differed significantly from those of healthy ethmoid mucosa, as well as tissue from 4 surrounding anatomical sites in both patients with chronic sinusitis and controls. Alterations specific to the polyp tissue included downregulated genes, prolactin-induced protein (fold change 377.2 ± 169.0, P < .0001), and zinc α2-glycoprotein (fold change 72.1 ± 26.5, P < .0001), as well as upregulated genes, met proto-oncogene (fold change 2.5 ± 0.7, P = .029), and periostin (fold change 7.5 ± 3.4, P = .003). No significant differences in gene expression was found for neurabin 2 (fold change 1.0, P = .99).

CONCLUSION

The transcriptional pattern of ethmoid polyps appears to be unique compared with other subsites in the sinonasal cavity of patients with chronic sinusitis. Care must be taken when collecting specimens for molecular studies of the sinonasal tract to differentiate polyp from nonpolyp tissue in chronic sinusitis.

Microarray gene analysis of Toll-like receptor signaling elements in chronic rhinosinusitis with nasal polyps

OBJECTIVE

To identify the regulatory mechanisms of Toll-like receptor (TLR)-associated genes in chronic rhinosinusitis (CRS) with nasal polyps (NP) using gene microarray analyses.

METHODS

We pooled: (1) NP biopsy specimens from 10 nonatopic CRS patients and (2) healthy mucosal tissue from 10 additional nonatopic healthy patients (controls). These pooled samples were evaluated by gene microarrays that included 125 genes for TLRs and associated signaling elements. To validate gene product expressions, 20 NP and 15 normal nasal turbinate tissues were evaluated for TLR-9 expression by immunohistochemical staining and Western blots using samples from gland cells, epithelial cells, and mononuclear cells cytologically identified by HE staining.

RESULTS

In pooled NP samples compared to pooled controls, 4 genes were upregulated (≥ 2-fold higher expression) and 19 were downregulated (≤ 0.5-fold lower expression). TLR-9 was an upregulated gene in NP tissue. Compared to control tissue, there were significantly higher percentages of TLR-9 positively stained NP gland cells, epithelial cells, and mononuclear cells (p < 0.001). On Western blots, while both normal and NP tissues expressed TLR-9 protein, the expression was significantly more pronounced for NP tissue (p < 0.001).

CONCLUSIONS

Inflammation associated with CRS may be due to dysregulated innate immune elements, particularly TLR-9 and its associated signal transduction elements, which may impact upon prolonged activation of adaptive immune responses in the sinonasal mucosa.

Fungus: a role in pathophysiology of chronic rhinosinusitis, disease modifier, a treatment target, or no role at all?

Fungal spores, due to their ubiquitous nature, are continuously inhaled and deposited on the airway mucosa. This article focuses on the potential role of fungi in chronic rhinosinusitis (CRS). Five forms of fungal disease affecting the nose and paranasal sinuses have been recognized: (1) acute invasive fungal rhinosinusitis (including rhinocerebral mucormycosis), (2) chronic invasive fungal rhinosinusitis, (3) granulomatous invasive fungal rhinosinusitis, (4) fungal ball (mycetoma), and (5) noninvasive (allergic) fungal rhinosinusitis. There are several potential deficits in the innate and potentially also acquired immunity of CRS patients that might reduce or change their ability to react to fungi. There are not many arguments to suggest a causative role for fungi in CRS with or without nasal polyps. However, due to the intrinsic or induced change in immunity of CRS patients, fungi might have a disease-modifying role.

Evidence for altered activity of the IL-6 pathway in chronic rhinosinusitis with nasal polyps

BACKGROUND

IL-6 activates T(H)17 cells and regulates the response of B lymphocytes and regulatory T cells. The IL-6 receptor and the membrane protein, glycoprotein 130 (gp130), form an active signaling complex that signals through signal transducer and activator of transcription 3 (STAT3) and other signaling molecules. Both the IL-6 receptor (IL-6R) and gp130 can be found in soluble forms that regulate the pathway.

OBJECTIVE

We measured IL-6 signaling components and IL-17 in chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP), CRS without nasal polyps (CRSsNP), and controls to assess the IL-6 pathway in CRS.

METHODS

IL-6, soluble IL-6R, soluble gp130 (sgp130), and IL-17 were measured in sinus tissue extracts and in nasal lavage fluid by either cytokine bead array or ELISA. phosphoSTAT3 (p-STAT3) was determined by Western blot and by immunohistochemistry.

RESULTS

IL-6 protein was significantly (P < .001) increased in CRSwNP compared with CRSsNP and controls. Soluble IL-6R was also increased in nasal polyp compared with control tissue (P < .01). Despite elevated IL-6 and sIL-6R, IL-17A, E, and F were undetectable in the sinus tissue from most of the patients with CRS and controls. p-STAT3 levels were reduced in the polyp tissue, possibly indicating reduced activity of IL-6 in the tissue. sgp130 was elevated in CRSwNP compared with CRSsNP and controls.

CONCLUSION

p-STAT3 levels are decreased in CRSwNP despite increased levels of IL-6 and sIL-6R and are associated with the absence of an IL-17 response. This may be a response to elevated levels of sgp130, a known inhibitor of IL-6 signaling. These results indicate that IL-6 and its signaling pathway may be altered in CRSwNP.

Gene-expression signatures of nasal polyps associated with chronic rhinosinusitis and aspirin-sensitive asthma

PURPOSE OF REVIEW

The purpose of this review is to highlight recent advances in gene-expression profiling of nasal polyps in patients with chronic rhinosinusitis and aspirin-sensitive asthma.

RECENT FINDINGS

Gene-expression profiling has allowed simultaneous interrogation of thousands of genes, including the entire genome, to better understand distinct biological and clinical phenotypes associated with nasal polyps. The genes with altered expression in nasal polyps are involved in many cellular processes, including growth and development, immune functions, and signal transduction. The wide-ranging and typically nonoverlapping results reported in the published studies reflect methodological and demographic differences. The identified genes present possible novel therapeutic targets for nasal polyps associated with chronic rhinosinusitis and aspirin-sensitive asthma.

SUMMARY

Gene-expression profiling is a powerful technology that allows definition of expression signatures to characterize patient subgroups, predict response to treatment, and offer novel therapies. Although the ability to interpret the meaning of the individual gene in these signatures remains a challenge, integrated analysis of a large number of these signatures with other genome-scale data sets and more traditional targeted approaches has a potential to revolutionarize understanding and treatment of chronic rhinosinusitis and aspirin-sensitive asthma.

Genetic polymorphisms in chronic hyperplastic sinusitis with nasal polyposis

OBJECTIVES/HYPOTHESIS

Although many proinflammatory cytokines have been identified in nasal polyp tissue, the initial trigger that causes this inflammation characterized by edema, lymphocytosis, and eosinophilia, is still unknown. The purpose of the present study is to identify the presence of genetic polymorphisms in proinflammatory, anti-inflammatory, and chemokine genes that might contribute to genetic susceptibility to chronic hyperplastic sinusitis with nasal polyposis (CHSwNP).

STUDY DESIGN

Case control study.

METHODS

Buccal swabs were taken from the left and right oral mucosal surfaces from 179 patients with CHSwNP and 153 nonpolyposis controls with the Purgene DNA purification protocol (Gentra). Genotyping assays for cytokine gene loci were performed on 14 cytokine genes using the iPlex Gold and the Mass Array Compact system (Sequenom, San Diego, CA). Tests of Hardy-Weinberg equilibrium proportions were performed separately in the cases and controls. Tests for evidence of association between alleles at each single-nucleotide polymorphism (SNP) and case-control status were performed using unconditional logistic regression.

RESULTS

The frequency of the A allele in a SNP located in tumor necrosis factor (TNF)-alpha (rs1800629) is significantly different in patients with nasal polyposis versus controls without nasal polyposis, 18.6% and 11.5%, respectively with an individuals' odds of susceptibility to nasal polyps increasing almost two-fold (odds ratio, 1.86; confidence interval, 1.4-3.09) given at least one copy of the A allele at this SNP. All other cytokine gene polymorphisms of both inflammatory, anti-inflammatory, and chemokine genes were not statistically different between the two groups.

CONCLUSIONS

TNF-alpha-308, a SNP in the promoter region of this cytokine gene is associated with increased odds of developing nasal polyposis. TNF-alpha is a potent immuno-mediator and proinflammatory cytokine that has been implicated in the pathogenesis of a large number of human diseases. The location of this gene on the short arm of chromosome 6, with the major histocompatibility complex genes and complement, has raised the probability that polymorphism within this locus may contribute to a genetic association of this region of the genome with a wide variety of infectious and autoimmune diseases.

Microarray analysis of distinct gene transcription profiles in non-eosinophilic chronic sinusitis with nasal polyps

BACKGROUND

Recent literature has indicated the feasibility of microarray analysis in the characterization of chronic sinusitis. We hypothesized that previously unexplored inflammatory mechanisms would be involved in the pathophysiology of noneosinophilic chronic rhinosinusitis with nasal polyps (NE-CRSwNP) and that this technology could be used to identify the gene expression of these novel and previously known mediators.

METHODS

Patients with CRSwNP failing medical therapy were prospectively enrolled and NP tissue was removed at time of surgery. NE-CRSwNP was diagnosed based on clinical parameters including absence of allergic disease and confirmed with histopathology showing lack of eosinophilic infiltration. Messenger RNA (mRNA) transcripts extracted from study and control patients were then subjected to microarray analysis using Affymatrix based chips. Validation of findings was then confirmed via quantitative reverse transcription polymerase chain reaction (qRT-PCR).

RESULTS

Microarray analysis revealed activation of pathways involved in antigen presentation, cellular movement, hematopoiesis, carcinogenesis, apoptosis, and cell signaling. Previously unexplored genes of interest were identified and their differential regulation was validated via qRT-PCR. Our data showed up-regulation of innate inflammation genes (IL-6, IL-8, and monocyte chemoattractant protein 1), hypoxia-induced inflammation 1alpha, and fibrosis (tenascin) and lack of up-regulation of genes associated with allergic, eosinophilic inflammation (IL-4 and IL-13). Additionally, the genes for CXCL1 and autocrine motility factor receptor were novelly identified to be up-regulated.

CONCLUSION

This study explores the utility of gene microarray technology in identifying unexplored targets of immune dysregulation in NE-CRSwNP. Furthermore, the data characterize the immunologic profile of NE-CRSwNP as it differs from other forms of CRSwNP, in particular, those known to be associated with eosinophilic inflammation.

Gene expression profiles of nasal polyps associated with allergic rhinitis

BACKGROUND

Nasal polyp (NP) is a common and frequently occurring disease in otorhinolaryngology head and neck surgery, the pathogenesis of which remains unclear. Differentially expressed genes of mucosal tissues from NP, allergic rhinitis (AR), and normal nasal cavities were screened out by oligonucleotide chip technique and verified by real-time polymerase chain reaction (PCR) and immunohistochemical staining.

OBJECTIVE

To study gene expression profiles of nasal polyps associated with AR and explore the pathogenic mechanisms of NP at the level of molecular biology.

METHODS

Using oligonucleotide chip technique HG-U133A2.0 (Affymetrix, Santa Clara, CA) containing 14500 human full-length genes, gene expression profiles of NP tissues from 6 patients with AR-associated NP, mucosal tissues from the inferior nasal concha of 6 AR patients, and mucosal tissues from the inferior nasal concha of 6 patients with normal nasal cavities were assayed, and differentially expressed genes were analyzed, from which 2 genes (CCL20 and IL-8) that were most up-regulated and 2 genes (RGS1 and GPK4) that were most down-regulated were chosen and verified by real-time PCR. CCL20 protein expression in the NP tissues and normal nasal mucosal tissues of the inferior nasal concha was detected by immunohistochemical staining.

RESULTS

Several hundred differentially expressed genes were screened out by gene chip technique, the functions of which involved inflammatory reaction, immune response, immunoregulation, and signal transduction. Paired comparison of the 3 groups showed the existence of CCL20 up-regulation by more than 2-fold. This result was consistent with that of fluorescent quantitative PCR for differentially expressed genes CCL20, IL-8, RGS1, and GPK4. Immunohistochemical staining showed strong positive expression of CCL20 protein in epithelial cells and submucosal glanular cells of NP tissues and weak positive expression in those of mucosal tissues of the normal inferior nasal concha. The difference was statistically significant (P < .05).

CONCLUSION

There were differences in gene expression profiles of AR associated NP, and these differentially expressed genes provide new cues for the study of pathogenesis of NP. Up-regulation of chemokine CCL20 may be an important factor of NP occurrence, and down-regulation of signal transduction genes may also be involved in the development of NP.

Significance of susceptible gene expression profiles in nasal polyposis

Nasal polyposis (NP) is a common chronic inflammatory disease of the rhinosinus mucosa and a complex disease with strong genetic and environmental components. During the past 10 to 20 yr, many studies have been performed to determine differential gene expression profiles between NP and normal nasal tissues, in order to identify susceptible genes that are associated with NP-related traits. Despite achievement in the identification of candidate genes and their associated pathogenic pathways, the large challenges remain as the genetic and molecular alterations required for its development and progression are still unclear. Therefore, the development of novel, powerful tools for gene discovery, and a closer integration of genetics and medical biology would provide valuable insight into the pathogenesis of NP.

Perspectives on the etiology of chronic rhinosinusitis: an immune barrier hypothesis

BACKGROUND

Chronic rhinosinusitis (CRS) has been defined as persistent symptomatic inflammation of the nasal and sinus mucosa resulting from the interaction of multiple host and environmental factors. Recent studies have implicated Alternaria fungi or toxigenic Staphylococcus aureus as critical agents in CRS pathogenesis. The emphasis on environmental agents in CRS etiology has focused interest toward elimination of those agents as the prime mechanism of therapy. This viewpoint is in marked contrast to the current perspective on some other chronic inflammatory epithelial disorders that afflict the skin, lungs, and gut, wherein host factors are believed to predispose to disease expression in the presence of ubiquitous environmental agents.

METHODS

The current review evaluates CRS etiology from this perspective and considers that CRS develops, in part, as an outcome of a dysfunctional host response. Specifically, evidence from our laboratory and others will be reviewed indicating that CRS is associated with a failure of the mechanical and immunologic barriers across the nasal mucosa. The hypothesis would further propose that genetic and epigenetic variation predisposes susceptible individuals to barrier failure in the presence of environmental stress leading to CRS.

RESULTS

From this unifying perspective, bacteria and fungi are seen as disease modifiers rather than primary etiologic agents.

CONCLUSION

The goal is to place concepts of CRS pathophysiology in a framework consistent with a current understanding of chronic inflammation in general and epithelial disease in particular.

[Diversity of nasal polyps in microarray technology research]

Nasal polyps, according to many authors, generate as a result of chronic inflammation process with activation of cytokines, immunological reaction mediators that regulate proliferation, differentiation and cell apoptosis. Clarifying molecular mechanisms present in those disturbances may have diagnostic and prognostic value in evaluation of recurrence, dynamics and differentiation of nasal polyps as well as in their therapy.

AIM

The aim of the work was an analysis of nasal polyps on the basis of molecular, histopathological and clinical picture as well as comparing differentiated genes transcription in nasal polyps and proper nasal mucosa.

MATERIAL AND METHOD

Oligonucleotide array with HGU 133A - Affymetrix were used to analyze the expression of 22,283 genes in nasal polyp tissues from 17 patients. The control group consisted of 8 tissue samples from patients after nasal septoplasty surgery.

RESULTS

All the samples could be classified to nasal polyps group or proper mucosa group, it reflected significant differences in genes profile expression in both groups. The evaluation of 22,283 genes transcriptions showed that in most cases nasal polyps tissue reflect classification connected with dominant inflammation cells infiltration. The data obtained let distinguish subgroups connected with clinical condition of the patients. The subgroup with massive nasal and sinus polyposis, eosinophilia and differentiated lower respiratory airways hyperactivity and the subgroup without eosinophilia infiltration may be distinguished. The data obtained suggest that molecular mechanisms may influence on the promotion and kind of inflammation process as well as the clinical course of nasal polyps.

Gene expression profiling of nasal polyps associated with chronic sinusitis and aspirin-sensitive asthma

OBJECTIVE

To identify genes whose expression is most characteristic of chronic rhinosinusitis and aspirin-sensitive asthma through genome-wide transcriptional profiling of nasal polyp tissue.

STUDY DESIGN

Prospective, controlled study conducted at a tertiary care institution.

METHODS

Thirty genome-wide expression microarrays were used to compare nasal polyp tissue from patients with chronic rhinosinusitis alone (CRS, n = 10) or chronic rhinosinusitis and a history of aspirin-sensitive asthma (ASA, n = 10) to normal sinonasal mucosa from patients who underwent surgery for non-sinus related conditions (controls, n = 10). Genes found to be most characteristic of each polyp phenotype, as determined from bioinformatic analyses, were validated using real-time quantitative polymerase chain reaction (RT-PCR) and immunohistochemistry in different patient sets.

RESULTS

The transcriptional signature of the control mucosa was distinctly different from that of either polyp phenotype. Genes most characteristic of the CRS phenotype included two upregulated genes--met proto-oncogene (MET) and protein phosphatase 1 regulatory subunit 9B (PPP1R9B)-and two downregulated genes--prolactin-induced protein (PIP) and zinc alpha2-glycoprotein (AZGP1). The gene most characteristic of the ASA phenotype was periostin (POSTN), which was upregulated relative to controls. Differences between the CRS and ASA phenotypes were associated with alterations in the 6p22, 22q13, and 1q23 chromosomal regions.

CONCLUSIONS

Nasal polyps appear to have characteristic transcriptional signatures compared to normal sinonasal mucosa. The five genes identified in this study likely play roles in the pathogenesis of polyps associated with CRS and ASA, and are therefore attractive targets for novel medical therapies for these common debilitating diseases.

Inflammatory genes in nasal polyposis

PURPOSE OF REVIEW

This paper is a review of the most recent literature concerning the role of inflammatory genes in nasal polyposis. The data provide evidence of a pivotal role for some inflammatory mediators in the development and maintenance of nasal polyps.

RECENT FINDINGS

Nasal polyposis is a common disease of the nasal mucosa; the exact mechanisms leading its development are still unknown. The role of the immune system in the pathogenesis of this disease is poorly understood. This lack of understanding makes definitive treatment very difficult. Activated eosinophils are a prominent feature of nasal polyps. Their presence in tissue results from a complex series of events that regulates their influx from the vasculature, as well as their movement, activation and survival within the tissue. Several studies have demonstrated that there are many potent chemoattractants that can activate eosinophils and trigger the inflammatory response.

SUMMARY

Cytokines, chemokines and growth factors play an important role in the persistence of mucosal inflammation associated with nasal polyps. Metalloproteinases seem to be crucial in nasal tissue remodeling in these patients. Arachidonic acid metabolites seem to be particularly important in the pathogenesis of nasal polyps in patients with aspirin hypersensitivity. We discuss the contribution of each one for the polyp formation.

Microarray cDNA to identify inflammatory genes in nasal polyposis

BACKGROUND

The objective of this study was to investigate the spectrum of inflammatory gene expression in patients with nasal polyposis.

METHODS

The cDNA microarray technique was used to identify gene expression in tissue samples from nasal polyps and adjacent inflammatory nasal mucosa of 21 patients with nonallergic nasal polyposis. To validate the microarray analysis, we compared the expression of five genes by reverse transcription-polymerase chain reaction (RT-PCR): tumor necrosis factor, IL-5, IL-9, fibroblast growth factor, and transforming growth factor (TGF)-beta1.

RESULTS

We tested 96 different inflammatory genes in our samples. Thirty-six genes exhibited differences in expression between the two tissue types. In all 36 genes the level of expression was greater in the inflammatory mucosa than the polyps. The RT-PCR confirmed the cDNA results.

CONCLUSION

We believe that the high expression of TGF-beta1 in inflammatory mucosa compared with the low expression in polyps may reflect an important role in the inhibitory mechanisms of nasal polyposis.