Expression of osteopontin in chronic rhinosinusitis with and without nasal polyps

The Role and Clinical Relevance of Osteopontin in Allergic Airway Diseases

The airway epithelium is exposed to numerous external irritants including infectious agents, environmental allergens, and atmospheric pollutants, releasing epithelial cytokines including thymic stromal lymphopoietin (TSLP), IL-33, and IL-25 and initiating downstream type 2 (IL-4, IL-13, and IL-5) and IgE-driven pathways. These pathways trigger the initiation and progression of allergic airway diseases, including chronic rhinosinusitis with nasal polyps (CRSwNP), allergic rhinitis (AR), and allergic asthma. However, the use of biological agents that target downstream cytokines, such as IL-5, IL-4, and IL-13 receptors and IgE, might not be sufficient to manage some patients successfully. Instead of blocking downstream cytokines, targeting upstream epithelial cytokines has been proposed to address the complex immunologic networks associated with allergic airway diseases. Osteopontin (OPN), an extracellular matrix glyco-phosphoprotein, is a key mediator involved in Th1-related diseases, including systemic lupus erythematosus, multiple sclerosis, inflammatory bowel disease, and rheumatoid arthritis. Emerging evidence, including ours, indicates that epithelial-cell-derived OPN also plays an essential role in Th2-skewed airway diseases, including CRSwNP, AR, and allergic asthma involving the Th17 response. Therefore, we reviewed the current knowledge of epithelial-cell-derived OPN in the pathogenesis of three type-2-biased airway diseases and provided a direction for its future investigation and clinical relevance.

Sinonasal Tissue Remodelling during Chronic Rhinosinusitis

The purpose of this review is to summarise contemporary knowledge of sinonasal tissue remodelling during chronic rhinosinusitis (CRS), a chronic disease involving long-term inflammation of the paranasal sinuses and nasal passage. The concept of tissue remodelling has significant clinical relevance because of its potential to cause irreversibility in chronic airway tissues. Recent studies have indicated that early surgical treatment of CRS may improve clinical outcome. Tissue remodelling has been described in the literature extensively with no consensus on how remodelling is defined. This review describes various factors implicated in establishing remodelling in sinonasal tissues with a special mention of asthma as a comorbid condition. Some of the main histological features of remodelling include basement membrane thickening and collagen modulation. This may be an avenue of research with regard to targeted therapy against remodelling in CRS.

Protein expression profiling suggests relevance of noncanonical pathways in isolated pulmonary embolism

Patients with isolated pulmonary embolism (PE) have a distinct clinical profile from those with deep vein thrombosis (DVT)-associated PE, with more pulmonary conditions and atherosclerosis. These findings suggest a distinct molecular pathophysiology and the potential involvement of alternative pathways in isolated PE. To test this hypothesis, data from 532 individuals from the Genotyping and Molecular Phenotyping of Venous ThromboEmbolism Project, a multicenter prospective cohort study with extensive biobanking, were analyzed. Targeted, high-throughput proteomics, machine learning, and bioinformatic methods were applied to contrast the acute-phase plasma proteomes of isolated PE patients (n = 96) against those of patients with DVT-associated PE (n = 276) or isolated DVT (n = 160). This resulted in the identification of shared molecular processes between PE phenotypes, as well as an isolated PE-specific protein signature. Shared processes included upregulation of inflammation, response to oxidative stress, and the loss of pulmonary surfactant. The isolated PE-specific signature consisted of 5 proteins: interferon-γ, glial cell line-derived neurotrophic growth factor, polypeptide N-acetylgalactosaminyltransferase 3, peptidyl arginine deiminase type-2, and interleukin-15 receptor subunit α. These proteins were orthogonally validated using cis protein quantitative trait loci. External replication in an independent population-based cohort (n = 5778) further validated the proteomic results and showed that they were prognostic for incident primary isolated PE in individuals without history of VTE (median time to event: 2.9 years; interquartile range: 1.6-4.2 years), supporting their possible involvement in the early pathogenesis. This study has identified molecular overlaps and differences between VTE phenotypes. In particular, the results implicate noncanonical pathways more commonly associated with respiratory and atherosclerotic disease in the acute pathophysiology of isolated PE.

International consensus statement on allergy and rhinology: rhinosinusitis 2021

I.

EXECUTIVE SUMMARY

BACKGROUND: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR-RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR-RS-2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence-based findings of the document.

METHODS

ICAR-RS presents over 180 topics in the forms of evidence-based reviews with recommendations (EBRRs), evidence-based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary.

RESULTS

ICAR-RS-2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence-based management algorithm is provided.

CONCLUSION

This ICAR-RS-2021 executive summary provides a compilation of the evidence-based recommendations for medical and surgical treatment of the most common forms of RS.

Non-Reflex Defense Mechanisms of Upper Airway Mucosa: Possible Clinical Application

The sinonasal mucosa has an essential role in defense mechanisms of the upper respiratory tract. The innate immune system presents the primary defense against noxious microorganisms followed by induction of the adaptive immune mechanisms as a consequence of the presence of pathogens. This well-known activation of adaptive immune system in response to presence of the antigen on mucosal surfaces is now broadly applicated in vaccinology research. Prevention of infectious diseases belongs to substantial challenges in maintaining the population health. Non-invasive, easily applicable mucosal vaccination purposes various research opportunities that could be usable in daily practice. However, the existence of multiple limitations such as rapid clearance of vaccine from nasal mucosa by means of mucociliary transport represents a great challenge in development of safe and efficient vaccines. Here we give an updated view on nasal functions with focus on nasal mucosal immunity and its potential application in vaccination in nearly future.

Osteopontin plays a pivotal role in increasing severity of respiratory syncytial virus infection

The molecular mechanisms underlying susceptibility to severe respiratory syncytial virus (RSV) infection remain poorly understood. Herein, we report on the role of osteopontin (OPN) in regulation of RSV infection in human epithelial cells and how interleukin-1 beta (IL-1β), a cytokine secreted soon after RSV infection, when persistently expressed can induce OPN expression leading to increased viral infection. We first compared OPN expression in two human epithelial cell lines: HEK-293 and HEp-2. In contrast to HEp-2, HEK-293 expresses low levels of pro-caspase-1 resulting in decreased IL-1β expression in response to RSV infection. We found a correlation between low IL-1β levels and a delay in induction of OPN expression in RSV-infected HEK-293 cells compared to HEp-2. This phenomenon could partially explain the high susceptibility of HEp-2 cells to RSV infection versus the moderate susceptibility of HEK-293 cells. Also, HEK-293 cells expressing low levels of pro-caspase-1 exhibit decreased IL-1β expression and delayed OPN expression in response to RSV infection. HEK-293 cells incubated with human rIL-1β showed a dose-dependent increase in OPN expression upon RSV infection. Also, incubation with rOPN increased RSV viral load. Moreover, HEp-2 cells or mice infected with a mucogenic RSV strain RSV-L19F showed elevated levels of OPN in contrast to mice infected with the laboratory RSV strain rA2. This correlated with elevated levels of OPN following infection with RSV-L19F compared to rA2. Together, these results demonstrate that increased OPN expression is regulated in part by IL-1β, and the interplay between IL-1β and OPN signaling may play a pivotal role in the spread of RSV infection.

Osteopontin induced vascular endothelial growth factor production in dispersed nasal polyp cells through the phosphatidylinositol 3-kinase-protein kinase B and the extracellular signal-regulated kinase 1/2 pathways

BACKGROUND

Osteopontin (OPN) is involved in cell survival, migration, and angiogenesis. The role of OPN in inducing angiogenesis in tumor has been confirmed. In this study, we investigated the expression of OPN in patients with chronic rhinosinusitis (CRS) with nasal polyp (NP) and the relationship of OPN with vascular endothelial growth factor (VEGF) production.

METHODS

We enrolled 45 subjects with CRS (25 with CRS with NPs [CRSwNP] and 20 subjects with CRS without NPs [CRSsNP]), and with 14 normal controls to determine the expression of OPN and VEGF. The distribution, messenger RNA (mRNA), and protein levels of OPN and VEGF were examined by immunohistochemistry, quantitative polymerase chain reaction, and enzyme-linked immunosorbent assay, respectively. The effect of OPN on the VEGF production was tested in dispersed NP cells (DNPC) and the involved signaling pathways were examined by Western blot.

RESULTS

In NP tissue of the subjects with CRSwNP, the epithelial cells, interstitial cells, glandular cells, and endothelial cells were positive for OPN and VEGF staining, whereas OPN and VEGF immunoactivity in specimens of subjects with CRSsNP and in normal controls was significantly reduced. We found that the immunostainings, the mRNA expression, and the protein levels of OPN and VEGF were significantly increased in NPs compared with normal controls. OPN induced VEGF production by DNPCs in a time- and dose-dependent manner through phosphatidylinositol 3-kinase- protein kinase B and the extracellular signal-regulated kinase 1/2 pathway. Moreover, VEGF also induced OPN production, which formed a positive feedback between OPN and VEGF.

CONCLUSION

Our findings demonstrated that OPN and VEGF were overproduced in NPs and that OPN induced VEGF production, which indicated that OPN-VEGF axis might contribute to angiogenesis in NPs.

Wheatgrass extract inhibits hypoxia-inducible factor-1-mediated epithelial-mesenchymal transition in A549 cells

BACKGROUND/OBJECTIVES

Epithelial-mesenchymal transition (EMT) is involved in not only cancer development and metastasis but also non-cancerous conditions. Hypoxia is one of the proposed critical factors contributing to formation of chronic rhinosinusitis or nasal polyposis. Wheatgrass (Triticum aestivum) has antioxidant, anti-aging, and anti-inflammatory effects. In this study, we analyzed whether wheatgrass has an inhibitory effect on the EMT process in airway epithelial cells.

MATERIALS/METHODS

A549 human lung adenocarcinoma cells were incubated in hypoxic conditions (CO₂ 5%/O₂ 1%) for 24 h in the presence of different concentrations of wheatgrass extract (50, 75, 100, and 150 µg/mL) and changes in expression of epithelial or mesenchymal markers were evaluated by immunoblotting and immunofluorescence. Accordingly, associated EMT-related transcriptional factors, Snail and Smad, were also evaluated.

RESULTS

Hypoxia increased expression of N-cadherin and reduced expression of E-cadherin. Mechanistically, E-cadherin levels were recovered during hypoxia by silencing hypoxia inducible factor (HIF)-1α or administering wheatgrass extract. Wheatgrass inhibited the hypoxia-mediated EMT by reducing the expression of phosphorylated Smad3 (pSmad3) and Snail. It suppressed the hypoxia-mediated EMT processes of airway epithelial cells via HIF-1α and the pSmad3 signaling pathway.

CONCLUSION

These results suggest that wheatgrass has potential as a therapeutic or supplementary agent for HIF-1-related diseases.

Differential short palate, lung, and nasal epithelial clone 1 suppression in eosinophilic and noneosinophilic chronic rhinosinusitis with nasal polyps: implications for pathogenesis and treatment

PURPOSE OF REVIEW

Short palate, lung, and nasal epithelial clone 1 (SPLUNC1) is an epithelium-secreted protein that is involved in innate immunity. A protective role for SPLUNC1 in lower respiratory inflammation and chronic rhinosinusitis (CRS) has recently been recognized.

RECENT FINDINGS

An impaired epithelial immune barrier has been proposed to play a critical role in the pathogenesis of CRS. Recent research has demonstrated that SPLUNC1 is profoundly reduced in polyp tissues of CRS with nasal polyps (CRSwNP) compared with control tissues. Studies investigating the differential expression of SPLUNC1 in eosinophilic and noneosinophilic CRSwNP have been published. Nasal SPLUNC1 expression was inhibited by Th2 cytokines (IL-4 and IL-13) but was stimulated by toll-like receptor (TLR) agonists and glucocorticoids. Decreased SPLUNC1 expression in the sinus mucosa is associated with positive Pseudomonas aeruginosa bacterial colonization and poor surgical outcomes in CRS patients.

SUMMARY

These studies identify the role of SPLUNC1 in sinonasal innate immunity and the pathogenesis of CRS. Defective expression of SPLUNC1 in CRSwNP patients may lead to insufficient maintenance of the epithelial barrier function and enhanced bacterial colonization. The use of SPLUNC1 as a therapeutic target for CRSwNP remains to be determined.

The Impact of Angiotensin-Modulating Antihypertensives on Time Interval to Revision Surgery for Nasal Polyps

OBJECTIVE/HYPOTHESIS

Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) have been shown to suppress expression of periostin, a matricellular protein that is markedly elevated in nasal polyp tissue. The purpose of this study was to determine whether use of these antihypertensive agents affects the time to revision sinus surgery in patients with polyp regrowth.

STUDY DESIGN

Case series with chart review.

SETTING

Academic medical center.

SUBJECTS AND METHODS

Records were reviewed for 330 patients who underwent ≥2 operations for chronic sinusitis with nasal polyps from April 1987 through August 2015. The time between surgical interventions was compared with patient demographics and clinical characteristics, including use of ACEIs and ARBs.

RESULTS

Sixty patients were taking ACEIs or ARBs during the study period, of which 32 had concurrent asthma. The mean interval between polyp operations was 61.0 ± 45.2 months (range, 2-228.6 months). Among patients with asthma (n = 197), the mean time to revision surgery was prolonged by >2 years for those taking ACEIs or ARBs (81.0 vs 54.5 months, P = .006). A similar impact on time to revision surgery was not observed for nonasthmatics taking these medications (61.0 vs 65.2 months, P = .655).

CONCLUSION

Use of ACEIs and ARBs is associated with an increased time to revision sinus surgery among patients with concurrent nasal polyps and asthma. A possible mechanism of this observed effect is suppression of periostin expression through inhibition of the angiotensin pathway.

Decreased level of osteopontin in children with allergic rhinitis during sublingual immunotherapy

OBJECTIVE

Sublingual immunotherapy (SLIT) is proven to be very effective in the treatment of allergic rhinitis (AR), but its regulatory mechanism and biomarkers for predicting efficacy are still unknown. Osteopontin (OPN), as a recently described Th2 inflammation related protein, plays key role in the pathogenesis of AR. The aim of this study was to identify the expression and role of OPN during SLIT in children.

METHODS

Fifty house dust mite (HDM)-sensitized children with AR were enrolled in this study. AR children received HDM allergen extract or placebo for SLIT. Serum of different time points during treatment was collected and used for enzyme-linked immuno sorbent assay (ELISA) of OPN and related cytokines, respectively. Peripheral blood mononuclear cells from children after SLIT or placebo treatment were collected and stimulated with HDM with or without OPN/anti-OPN after one year's treatment.

RESULTS

Our results showed that expression of OPN protein was decreased after one year's therapy. The decreased OPN expression was positively related to decreased Th2 cytokines and negatively related to enhanced IL-10 and TGF-β expression. In vitro experiments confirmed that children received SLIT treatment showed decreased production of Th2 cytokines by PBMCs after HDM stimulation.

CONCLUSION

During SLIT, decreased OPN expression was related to low Th2 cytokine expression and enhanced IL-10 and TGF-β expression. High serum OPN expression predicts poor treatment efficacy. OPN may be used as a biomarker for SLIT treatment.

Expression and regulation of osteopontin in chronic rhinosinusitis with nasal polyps

BACKGROUND

Osteopontin (OPN) has been proposed to be associated with airway inflammation including asthma and chronic rhinosinusitis with nasal polyps (CRSwNP). This study sought to evaluate the expression and regulation of the OPN in CRSwNP patients.

METHODS

Nasal polyp (NP) tissues and normal tissues were collected from 30 CRSwNP patients and 16 control subjects. The expression and regulation of OPN, as well eosinophil (EOS) accumulation and activation, were examined in nasal tissues using DNA microarray, immunohistochemical (IHC), immunofluorescent (IF) staining and qPCR analysis. Moreover, the regulation of OPN in nasal epithelial cells and its effects on migration and activation of EOS were evaluated in vitro using flow cytometry, ELISA, qPCR and Western blot, etc.

RESULTS

DNA microarray analysis identified OPN as one of the 19 upregulated genes in polyp tissues. The mean number of OPN(+) cells in polyp tissues was found to be significantly increased compared with the normal controls (P < 0.01), and OPN(+) cells in polyp tissues significantly correlated with tissue eosinophilia [major basic protein (MBP)(+) cells; r = 0.51, P < 0.01]. Accordingly, the mRNA and protein levels of OPN in NP tissues were significantly higher than those in normal controls (P < 0.01). Poly I:C, flagellin and TLR-9 agonist CpG ODN, as well as TNF-α, IFN-γ, IL-6, IL-17A and TGF-β, significantly increased OPN mRNA expression in cultured PECs and NECs (P < 0.05). Recombinant human OPN significantly promoted the migration of EOS, as well as enhanced EOS cationic protein (ECP) production, in an in vitro dispersed NP cells (DNPCs) culture system (P < 0.05).

CONCLUSIONS

OPN promotes eosinophilic nasal inflammation in CRSwNP patients, which may represent a promising therapeutic target.

Clarithromycin and dexamethasone show similar anti-inflammatory effects on distinct phenotypic chronic rhinosinusitis: an explant model study

BACKGROUND

Phenotype of chronic rhinosinusitis (CRS) may be an important determining factor of the efficacy of anti-inflammatory treatments. Although both glucocorticoids and macrolide antibiotics have been recommended for the treatment of CRS, whether they have different anti-inflammatory functions for distinct phenotypic CRS has not been completely understood. The aim of this study is to compare the anti-inflammatory effects of clarithromycin and dexamethasone on sinonasal mucosal explants from different phenotypic CRS ex vivo.

METHODS

Ethmoid mucosal tissues from CRSsNP patients (n = 15), and polyp tissues from eosinophilic (n = 13) and non-eosinophilic (n = 12) CRSwNP patients were cultured in an ex vivo explant model with or without dexamethasone or clarithromycin treatment for 24 h. After culture, the production and/or expression of anti-inflammatory molecules, epithelial-derived cytokines, pro-inflammatory cytokines, T helper (Th)1, Th2 and Th17 cytokines, chemokines, dendritic cell relevant markers, pattern recognition receptors (PRRs), and tissue remodeling factors were detected in tissue explants or culture supernatants by RT-PCR or ELISA, respectively.

RESULTS

We found that both clarithromycin and dexamethasone up-regulated the production of anti-inflammatory mediators (Clara cell 10-kDa protein and interleukin (IL)-10), whereas down-regulated the production of Th2 response and eosinophilia promoting molecules (thymic stromal lymphopoietin, IL-25, IL-33, CD80, CD86, OX40 ligand, programmed cell death ligand 1, CCL17, CCL22, CCL11, CCL5, IL-5, IL-13, and eosinophilic cationic protein) and Th1 response and neutrophilia promoting molecules (CXCL8, CXCL5, CXCL10, CXCL9, interferon-γ, and IL-12), from sinonasal mucosa from distinct phenotypic CRS. In contrast, they had no effect on IL-17A production. The expression of PRRs (Toll-like receptors and melanoma differentiation-associated gene 5) was induced, and the production of tissue remodeling factors (transforming growth factor-β1, epidermal growth factor, basic fibroblast growth factor, platelet derived growth factor, vascular endothelial growth factor, and matrix metalloproteinase 9) was suppressed, in different phenotypic CRS by dexamethasone and clarithromycin in comparable extent.

CONCLUSIONS

Out of our expectation, our explant model study discovered herein that glucocorticoids and macrolides likely exerted similar regulatory actions on CRS and most of their effects did not vary by the phenotypes of CRS.

Chronic rhinosinusitis with nasal polyps and without nasal polyps is associated with increased expression of lysophosphatidic acid-related molecules

BACKGROUND

Chronic sinusitis with nasal polyps (CRSwNPs) or CRS without NPs (CRSsNPs) is associated with expression of various cytokines. Lysophosphatidic acid (LPA) generated by autotaxin (ATX), LPA-producing enzyme, initiates signaling cascade involved in the inflammatory responses and participates in diverse biological processes through LPA receptors, including cytokine production. We analyzed the expression and distribution patterns of LPA-related molecules in nasal secretion and sinus mucosa of normal controls and patients with CRSwNPs and CRSsNPs, to evaluate the possible effects of the ATX-LPA receptor axis on the pathogenesis of CRS.

METHODS

LPA levels in nasal secretion and the expression and distribution patterns of ATX and LPA receptors 1-3 (LPA1-3) in sinus mucosa were investigated using ELISA, real-time polymerase chain reaction, Western blot, and immunohistochemistry. We elucidated the effect of CRS-relevant cytokines on the expression of ATX and LPA receptors, using cultured sinus epithelial cells, and investigated the effect of LPA on the expression of CRS-relevant cytokines, using sinus mucosa explant culture.

RESULTS

LPA, ATX, and LPA1-3 levels are increased in CRSwNPs and CRSsNPs. ATX and LPA1-3 were localized to superficial epithelium, submucosal glands in normal and inflammatory mucosa, but in inflammatory mucosa, they were found in inflammatory cells. LPA1-3 were noted in endothelium. Sinus mucosa explant stimulated with LPA increasingly produced IL-4, IL-5, interferon gamma, and TNF-alpha, and in cultured epithelial cells stimulated with CRS-relevant cytokines, ATX, and LPA1-3 were differentially induced.

CONCLUSION

LPA in human sinus mucosa may play important roles in the pathogenesis of CRS, contributing to produce CRS-related cytokines. LPA-related molecules were increased in CRS, which may attribute to CRS-related cytokines.

Heavy metals in normal mucosa and nasal polyp tissues from Tunisian patients

Despite growing evidence that bacteria, fungi, allergens, and superantigens play a prominent role in the pathophysiology of nasal polyps (NP), the exact cause of polyposis is still unknown. The etiology of NP is considered multifactorial. Until now, there is no information on the presence of heavy metals, such as cadmium (Cd), chromium (Cr), nickel (Ni), and arsenic (As) or of their role, in the pathogenesis of NP disease. In this study, concentrations of these four metals in tissue of NP were determined using Atomic Absorption Spectrometry. The Ni, Cr, and As levels in NP tissues were 2.1-, 3.2-, and 8.0-fold higher than those of normal mucosa (p < 0.05), respectively. A strong effect of cumulative smoking as expressed in the number of pack per year (PY), Ni, As, and Cd levels in NP tissue samples of patients ever-smokers (1-20 and >20 PY) are significantly higher than those of non-smokers (p = 0.006, 0.002, and < 0.001, respectively). The highest As concentrations among patients lived at polluted areas (1-25 and > 25 years) were observed in both nasal mucosa and NP tissues. The Ni and As in both nasal mucosa and NP tissues of patients occupationally exposed were significantly higher than non-exposed group. Cr and As levels were found to be associated with NP stage classification (p < 0.05). This is the first report to describe an association between concentrations of metals (Cr, As, and Ni) in human NP tissues and the risk of NP disease. Tissue metal levels have increased due to smoking, environmental, and occupational exposure. Therefore, heavy metal exposure may increase the risk of NP in the Tunisian population. The considerable risk in the category of highest cumulative exposure argues for an association between heavy metals exposure and nasal polyposis risk. Future investigations with larger samples should better elucidate this association.

ICON: chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a public health problem that has a significant socio-economic impact. Moreover, the complexity of this disease due to its heterogeneous nature based on the underlying pathophysiology - leading to different disease variants - further complicates our understanding and directions for the most appropriate targeted treatment strategies. Several International/national guidelines/position papers and/or consensus documents are available that present the current knowledge and treatment strategies for CRS. Yet there are many challenges to the management of CRS especially in the case of the more severe and refractory forms of disease. Therefore, the International Collaboration in Asthma, Allergy and Immunology (iCAALL), a collaboration between EAACI, AAAAI, ACAAI, and WAO, has decided to propose an International Consensus (ICON) on Chronic Rhinosinusitis. The purpose of this ICON on CRS is to highlight the key common messages from the existing guidelines, the differences in recommendations as well as the gaps in our current knowledge of CRS, thus providing a concise reference. In this document we discuss the definition of the disease, its relevance, pharmacoeconomics, pathophysiology, phenotypes and endotypes, genetics and risk factors, natural history and co-morbidities as well as clinical manifestations and treatment options in both adults and children comprising pharmacotherapy, surgical interventions and more recent biological approaches. Finally, we have also highlighted the unmet needs that wait to be addressed through future research.

Histopathological evaluation of chronic rhinosinusitis: a critical review

BACKGROUND

Chronic rhinosinusitis (CRS) consists of a constellation of symptoms, including facial pressure/pain, hyposmia, rhinorrhea, and nasal congestion. On histopathological evaluation, the disease can be divided into pathophysiologically distinct subgroups. This study systematically reviews the literature regarding the unique histopathological findings of the various subtypes of CRS to determine the potential diagnostic value of performing tissue analysis of CRS specimens beyond routine hematoxylin and eosin (H&E) staining.

METHODS

A PubMed search was untaken to identify articles that evaluated the histopathological features of CRS. Six hundred fifty-four relevant articles were identified and after application of specific exclusion criteria, 71 articles were further reviewed in detail.

RESULTS

All articles included analysis of tissue samples from in-office biopsies or intraoperative specimens of patients who underwent sinus surgery. CRS was often further divided into subgroups and compared with each other and with a control group. The subgroups included CRS with and without nasal polyps, asthmatic and nonasthmatic patients, and with and without eosinophilia. Distinct inflammatory mediators were found for the different subgroups. Twenty-eight articles evaluated these inflammatory markers for their potential value as prognostic indicators.

CONCLUSION

CRS is a heterogeneous disease based on its histopathological findings. Information that is obtainable from light microscopy, but typically goes unreported, can serve as valuable prognostic indictors. However, routine H&E staining is suboptimal in distinguishing among the various subgroups of CRS. Assessment of specific inflammatory mediators in sinus mucosa specimens may help provide prognostic information and guide more tailored treatment for the individual patient.

Advances in asthma drug discovery: evaluating the potential of nasal cell sampling and beyond

INTRODUCTION

Inhaled corticosteroid anti-inflammatory therapy is effective at controlling disease symptoms of asthma, but a subset of patients remains symptomatic despite optimal treatment, creating a clear unmet medical need. Moreover, none of the currently available drugs for asthma are really disease-modifying or curative. Although murine models of asthma, based on transgenic and knockout animals, may offer an integrated pathophysiological system for studying the characteristics of airway inflammation and hyperresponsiveness, these alterations are noteworthily different compared with those observed in asthmatic patients. Since a clear functional and inflammatory relationship between the nasal mucosa and bronchial tissue in patients suffering from asthma and allergic rhinitis has been recognized, using preclinical models based on human nasal cells sampling might support a prompt and effective anti-inflammatory drug discovery in asthma.

AREAS COVERED

The authors provide a review, which discusses the potential role of nasal cell sampling and its application in advanced drug discovery for asthma. The contents range from the similarities and differences between asthma and allergic rhinitis up to artificial airway models based on sophisticated human lung-on-a-chip devices.

EXPERT OPINION

Nasal cell sampling and processing have reached a great potential in asthma drug discovery. The authors believe that models of asthma, which are based on human nasal cells, can provide valuable indications of proof of pharmacological and potential therapeutic efficacy in both preclinical and early clinical settings.

COX/PGE(2) axis critically regulates effects of LPS on eosinophilia-associated cytokine production in nasal polyps

BACKGROUND

Lipopolysaccharide (LPS) has shown heterogeneous effects on eosinophilic inflammation in airways. However, little is known about how LPS regulates pathogenesis of chronic rhinosinusitis with nasal polyps, a major form of eosinophilic inflammation in the upper airway.

OBJECTIVE

We sought to investigate the effect of LPS on cytokine production by dispersed nasal polyp cells (DNPCs).

METHODS

Either diclofenac-treated or untreated DNPCs were cultured with or without staphylococcal enterotoxin B (SEB) in the presence or absence of LPS, after which the levels of IL-5, IL-13, IL-17A and IFN-γ within the supernatant were measured. The effects of PGE(2) on LPS-induced responses by diclofenac-treated DNPCs were also examined. LPS-induced PGE(2) production and mRNA expression of COX-1, COX-2 and microsomal PGE(2) synthase-1 (m-PGES-1) were measured.

RESULTS

Staphylococcal enterotoxin B induced IL-5, IL-13, IL-17A and IFN-γ production by DNPCs. Pre-treatment with LPS prior to SEB stimulation inhibited production of these cytokines. After stimulation with LPS, PGE(2) production and expression of COX-2 and m-PGES-1 mRNA by DNPCs increased significantly. In the presence of diclofenac, the suppressive effects of LPS were eliminated. LPS pre-treatment enhanced SEB-induced IL-5, IL-13 and IL-17A production in diclofenac-treated DNPCs, while addition of PGE(2) inhibited IL-5, IL-13 and IFN-γ production. LPS alone induced IL-5, IL-13 and IFN- γ production by diclofenac-treated DNPCs, while the addition of EP2 and EP4 receptor-selective agonists, as well as PGE(2) itself, inhibited IL-5 and IL-13 production.

CONCLUSIONS AND CLINICAL RELEVANCE

These results suggest that the regulatory effects of LPS on eosinophilic airway inflammation are controlled via the COX-2/PGE(2) axis. For clinical implications, indiscreet use of non-steroidal anti-inflammatory drugs should be avoided in patients with chronic rhinosinusitis with nasal polyps.

Periostin and osteopontin are overexpressed in chronically inflamed sinuses

OBJECTIVE

In chronic rhinosinusitis (CRS), the inflammation leads to a proliferative response in the extracellular matrix (ECM). Periostin and osteopontin are 2 ECM proteins which have received attention for their roles in tissue remodeling in inflammatory diseases of the upper and lower airways. Transforming growth factor beta-1 (TGFβ1) is an inflammatory cytokine that has been implicated in fibrotic conditions affecting virtually every organ. In this study we seek to evaluate the differential expression of periostin, osteopontin, and TGFβ1 in the ethmoid sinus and nasal floor of patients with CRS. Furthermore, we seek to determine if a correlation exists between their differential expression in the nose and sinuses of patients with CRS.

METHODS

Biopsies from ethmoid sinus and nasal floor mucosa were taken from 15 patients undergoing functional endoscopic sinus surgery (FESS) for CRS. Complementary DNA (cDNA) microarray analysis demonstrated upregulation of periostin and osteopontin in the ethmoid sinus samples. Quantitative real-time polymerase chain reaction (RT-PCR) was performed for periostin, osteopontin, and TGFβ1. Statistical analysis was undertaken to examine correlations between the 3 genes of interest.

RESULTS

RT-PCR confirmed that periostin and osteopontin were overexpressed in the ethmoid samples compared to the nasal floor. The differential expression of both periostin and osteopontin showed significant correlation with TGFβ1.

CONCLUSION

Periostin and osteopontin appear to be involved in ECM remodeling seen in CRS. TGFβ1 may be an upstream inducer of CRS-related changes in ethmoid sinus mucosa.

Clara cell 10-kDa protein gene transfection inhibits NF-κB activity in airway epithelial cells

BACKGROUND

Clara cell 10-kDa protein (CC10) is a multifunctional protein with anti-inflammatory and immunomodulatory effects. Induction of CC10 expression by gene transfection may possess potential therapeutic effect. Nuclear factor κB (NF-κB) plays a key role in the inflammatory processes of airway diseases.

METHOD/RESULTS

To investigate potential therapeutic effect of CC10 gene transfection in controlling airway inflammation and the underlying intracellular mechanisms, in this study, we constructed CC10 plasmid and transfected it into bronchial epithelial cell line BEAS-2B cells and CC10 knockout mice. In BEAS-2B cells, CC10's effect on interleukin (IL)-1β induced IL-8 expression was explored by means of RT-PCR and ELISA and its effect on NF-κB classical signaling pathway was studied by luciferase reporter, western blot, and immunoprecipitation assay. The effect of endogenous CC10 on IL-1β evoked IL-8 expression was studied by means of nasal explant culture. In mice, CC10's effect on IL-1β induced IL-8 and nuclear p65 expression was examined by immunohistochemistry. First, we found that the CC10 gene transfer could inhibit IL-1β induced IL-8 expression in BEAS-2B cells. Furthermore, we found that CC10 repressed IL-1β induced NF-κB activation by inhibiting the phosphorylation of IκB-α but not IκB kinase-α/β in BEAS-2B cells. Nevertheless, we did not observe a direct interaction between CC10 and p65 subunit in BEAS-2B cells. In nasal explant culture, we found that IL-1β induced IL-8 expression was inversely correlated with CC10 levels in human sinonasal mucosa. In vivo study revealed that CC10 gene transfer could attenuate the increase of IL-8 and nuclear p65 staining in nasal epithelial cells in CC10 knockout mice evoked by IL-1β administration.

CONCLUSION

These results indicate that CC10 gene transfer may inhibit airway inflammation through suppressing the activation of NF-κB, which may provide us a new consideration in the therapy of airway inflammation.

Osteopontin levels are elevated in patients with asthma

Osteopontin (OPN) plays a role in T cell-mediated immunity, but its involvement in Th2-associated allergic responses, especially asthma, has not been investigated. This cross-sectional case-control study was designed to determine whether serum OPN levels are elevated in asthma patients and whether these correlated with disease severity. Serum samples were obtained from patients with mild (n = 42), moderate (n = 48) and severe (n = 39) asthma, and 41 healthy control subjects. OPN protein concentrations were measured by enzyme-linked immuno sorbent assay and were found to be significantly higher in all three asthma patient groups compared with healthy controls. There was no significant association between OPN concentration and disease severity. The data suggest a role for OPN in the pathogenesis of asthma. Further studies are needed to clarify the involvement of OPN in various aspects of asthma.

Role of osteopontin, a multifunctional protein, in allergy and asthma

Osteopontin (OPN) is an extracellular matrix protein and immune modulator with a wide range of functions. OPN is recognized as a key cytokine in Th1 immune responses, yet its potential involvement in allergic/asthmatic responses has been investigated only recently. Current data from molecular and cellular studies and studies of OPN-deficient mice provide evidence that OPN plays multiple roles in the regulation of allergic responses, including regulation of IgE response, inflammatory cell migration, and the development of airway fibrosis and angiogenesis. These results suggest that OPN is a pleiotropic cytokine that functions both systemically and locally in tissue mucosa. Notably, OPN is able to exert its effects through different functional domains, and the secreted and intracellular forms of OPN may have distinct functions. Future research to elucidate all aspects of OPN function is needed to ultimately establish its role in the regulation of immune responses and various disease processes, including those critically involved in the development of allergies and asthma.

Myeloperoxydase expression in the pathogenesis of nasal polyps

Nasal polyps are benign mucosal protrusions that expand into the nasal cavity. There are no any etiological factors that may explain the pathogenesis of nasal polyps but currently inflammation continues to be the major factor. As a result of inflammation, neutrophils become activated and migrate to the inflammatory area and form their bactericidal effects by producing free oxygen radicals. The objective of our study is to investigate the expression of myeloperoxydase enzyme, which is usually an indicator of leukocyte infiltration and is responsible in the formation of free oxygen radicals in polyp tissues and to determine its role in the pathogenesis of nasal polyps.

Osteopontin and allergic disease: pathophysiology and implications for diagnostics and therapy

Osteopontin (OPN) is a phosphoglycoprotein that is expressed by various immune cells in a secreted and intracellular form. It has cytokine, chemotactic and cell signaling functions enhancing Th1 and Th17 immunity and protects against apoptosis. Recent studies found OPN to be modulatory in cell-mediated and immediate-type allergic diseases. In allergic asthma, OPN enhances sensitization but downmodulates Th2-driven IL-4-dominated inflammation. The finding that OPN expression is augmented during specific immunotherapy supports a Th2 suppressive effect of OPN. In Th1-driven delayed-type allergy, such as allergic contact dermatitis, OPN supports dendritic cell migration and IL-12 expression and is secreted by T effector cells and keratinocytes, augmenting Th1-mediated allergy and supporting disease chronification. There are numerous missing links as to how OPN variants modulate allergic inflammation through different OPN receptors. OPN research in allergy is an interesting, rapidly expanding field that has high potential for translational research.

The expression of osteopontin and its association with Clara cell 10 kDa protein in allergic rhinitis

BACKGROUND

Osteopontin (OPN) is a multifunctional protein that has recently been linked to allergic diseases. Clara cell 10 kDa protein (CC10) is another protein linked to allergy, and has been suggested to have an inhibitory role in inflammatory airway diseases. At this time, it is not known whether OPN is involved in allergic rhinitis (AR) or if there is any association between CC10 and OPN in AR.

OBJECTIVE

To study the expression of OPN and its potential association with CC10 in AR.

METHODS

The expression of CC10 and OPN in nasal mucosa of AR patients was investigated. AR animal models were established by using wild-type and CC10-knockout mice. In some experiments, human recombinant CC10 protein was given to AR mice during either sensitization or challenge. The phenotypic changes were examined by histology and real-time RT-PCR. The direct effect of CC10 on the OPN expression in spleen mononuclear cells and on the OPN-induced inflammatory cytokine expression in BEAS-2B cells was measured through in vitro cell culture.

RESULTS

OPN expression was up-regulated, with a concomitant down-regulation of CC10, in AR patients, showing a significant negative correlation between their expression. Compared with control mice sensitized with PBS, the OPN expression was significantly increased in AR mice; such an increase was more prominent in CC10-knockout mice, compared with wild-type. Administration of CC10 during both sensitization and challenge could markedly ameliorate Th2-skewed inflammation and OPN expression in nasal mucosa. CC10 administration at the sensitization phase could also reduce spleen OPN expression. The in vitro study showed that CC10 directly down-regulated the OPN expression in spleen mononuclear cells stimulated with OVA and suppressed the OPN-induced expression of Th2 cytokines and pro-inflammatory cytokines in BEAS-2B cells.

CONCLUSION

In the context of allergic airway responses, CC10 can inhibit OPN expression and suppress the Th2-promoting function of OPN, resulting in CC10's inhibitory biological effects.

Quantitative expression of osteopontin in nasal mucosa of patients with allergic rhinitis: effects of pollen exposure and nasal glucocorticoid treatment

BACKGROUND

Osteopontin (OPN) is a multifunctional cytokine that has been primarily investigated in Th1 diseases. Recently, it has also been implicated in Th2-mediated allergic diseases, such as asthma. The expression of OPN in allergic rhinitis (AR) is currently unknown, as is the effect of intranasal glucocorticosteroids (GCs) on that expression.

METHODS

Subjects with AR were randomised to receive treatment with fluticasone propionate (FP) (n = 12) or a placebo (n = 16) over the grass pollen season and nasal biopsies were taken prior to, and during the season. OPN expression in the nasal mucosa was examined with immunohistochemistry. Healthy non-AR controls (n = 5) were used as a comparator.

RESULTS

OPN expression was detected in epithelial cells, subepithelial infiltrating/inflammatory cells and cells lining the vessels and glands of all subjects. Comparison of the pre- and peak-pollen season biopsy sections in placebo treated patients revealed no increase in OPN expression during the grass pollen season (5.7% vs 6.4%). Treatment with a local glucocorticosteroid did not alter the expression of OPN during pollen exposure (6.2% vs 6.7%).

CONCLUSION

OPN has been increasingly associated with the pathogenesis of various Th2-mediated diseases. However, our finding that the OPN expression in the nasal mucosa of AR patients is not significantly affected by allergen exposure and is comparable to that of the healthy controls, suggests that intracellular OPN is not directly involved in the pathogenesis of allergic rhinitis.

Osteopontin levels are elevated in patients with eosinophilic pneumonia

BACKGROUND AND OBJECTIVE

Osteopontin is a key cytokine involved in pro-inflammatory T helper type 1 (Th1)-associated immune responses, which has recently been implicated in allergic diseases. We investigated the pathogenic role of osteopontin in eosinophilic pneumonia.

METHODS

The concentrations of osteopontin and Th1- or Th2-associated cytokines were measured in BAL fluid (BALF) from 41 patients with eosinophilic pneumonia, including those with acute (AEP, n = 12), chronic (CEP, n = 16), or drug-induced eosinophilic pneumonia (DEP, n = 13). The results were compared with those from patients with other interstitial lung diseases. Immunocytochemistry and double immunofluorescence labelling were performed to determine the cellular source of osteopontin.

RESULTS

Osteopontin was significantly elevated in BALF from patients with eosinophilic pneumonia as compared with BALF from patients with drug-induced interstitial pneumonia, hypersensitivity pneumonitis, idiopathic interstitial pneumonia, or sarcoidosis, and also compared with BALF from healthy volunteers. Osteopontin concentrations elevated at the time of exacerbation decreased during clinical improvement, either spontaneously or as a result of corticosteroid therapy. Elevated concentrations of CXCL10, CCL17 and IL-10 were also detected in BALF from patients with eosinophilic pneumonia. Osteopontin concentrations in BALF of AEP patients were correlated with IL-5, as well as IL-10, CCL11, CCL17 and CXCL10 concentrations. In AEP and DEP patients, serum osteopontin concentrations were also elevated. Double immunofluorescence labelling showed that in patients with eosinophilic pneumonia, osteopontin was expressed in lung eosinophils.

CONCLUSIONS

Osteopontin is likely to contribute to the development of inflammation in patients with eosinophilic pneumonia.

Role of muscarinic receptor activation in regulating immune cell activity in nasal mucosa

BACKGROUND

The prevalence of airway inflammatory disorders keeps rising; its pathogenic mechanism is still not fully understood.

OBJECTIVE

The present study aimed to investigate the role of muscarinic receptor (M receptor) in regulating the immune cell activity in nasal mucosa by using surgical removed nasal mucosa from patients with nasal polyposis (NP) as a study platform.

METHODS

Human nasal mucosal sample was collected from inferior turbinectomy of 86 patients with NP or/and allergic rhinitis. Expression of tumor necrosis factor alpha (TNF-alpha), M receptor, OX40 ligand was measured in nasal mucosa by enzyme-linked immunosorbent assay, flow cytometry, and Western blotting assay.

RESULTS

When compared with non-NP (nNP) nasal mucosa, contents of TNF-alpha and TNF-alpha+ cells markedly increased in NP nasal mucosa; immune staining colocalized M3 receptor+ and TNF-alpha+ cells in NP nasal mucosa; exposure of isolated CD4+ T cells to methacholine induced the release of TNF-alpha. We also found CD11c+/M3 receptor+ cells in NP nasal mucosa. Methacholine increased the expression of OX40L in dendritic cells. Staphylococcal (S) aureus and S. enterotoxin B (SEB) were detected in NP nasal mucosa. Exposure of dendritic cells or naïve CD4+ T cells to SEB initiated the expression of M3 receptor at mRNA and protein levels.

CONCLUSIONS

The present data demonstrate that parasympathetic activity has the capacity to activate dendritic cells to release OX40 ligand, the latter induces CD4+ T cells to produce IL-4 and TNF-alpha that may further contribute to the pathogenesis of NP.

Chronic rhinosinusitis with and without nasal polyps is associated with decreased expression of glucocorticoid-induced leucine zipper

BACKGROUND

Chronic rhinosinusitis without nasal polyps (CRSsNP) and with nasal polyps (CRSwNP) is characterized by persistent inflammation of sinonasal mucosa. Glucocorticoid-induced leucine zipper (GILZ) is a recently described anti-inflammatory mediator.

OBJECTIVE

Here we analysed the expression of GILZ in CRSsNP and CRSwNP, its association with response to surgery, and its cytokine-driven expression regulation in the upper airways. Methods The messenger RNA (mRNA) and protein expression of GILZ in 33 CRSsNP, 32 CRSwNP, and 11 control samples was assessed by means of a quantitative RT-PCR and immunohistochemistry, respectively. Nasal explant culture was used to investigate the effect of IFN-gamma, IL-4, IL-13, IL-1beta, and TNF-alpha on GILZ mRNA expression in normal sinonasal mucosa.

RESULTS

The GILZ mRNA and protein expression was significantly suppressed in both CRSsNP and CRSwNP patients compared with controls. No significant difference in GILZ expression was found between CRSsNP and CRSwNP patients. Comparing patients responsive and patients recalcitrant to surgery, a significant further decrease of GILZ expression was found in recalcitrant patients both in the CRSsNP and in the CRSwNP group. IL-1beta, TNF-alpha, IL-4, and IL-13 reduced, whereas IFN-gamma enhanced GILZ mRNA levels in the sinonasal mucosa.

CONCLUSION

Down-regulated expression of GILZ may contribute to the pathogenesis of CRSsNP and CRSwNP and associate with response to surgery. GILZ expression in the upper airways can be regulated differentially by different cytokines.