The antimicrobial protein short palate, lung, and nasal epithelium clone 1 (SPLUNC1) is differentially modulated in eosinophilic and noneosinophilic chronic rhinosinusitis with nasal polyps

The expression and significance of nasal mucosal glandular hyperplasia and eosinophil infiltration in chronic rhinosinusitis

BACKGROUND

The pathophysiological mechanisms underlying nasal mucosal glandular changes in chronic rhinosinusitis (CRS) remains poorly understood.

OBJECTIVES

This study aimed to examine nasal mucosal glandular density and eosinophil (Eos) infiltration in CRS patients and their role in disease pathogenesis.

MATERIALS AND METHODS

HE staining was used to assess glandular density and Eos infiltration in nasal mucosal lesion tissues from 86 CRS patients during FESS (16 CRS without nasal polyps (CRSsNP), 55 non-eosinophilic CRS with nasal polyps (nECRSwNP), and 15 eosinophilic CRSwNP (ECRSwNP)). Immunohistochemical analysis was conducted to evaluate eosinophil cationic protein (ECP), lysozyme, and immunoglobulin A (IgA) expression within these tissues. The Kruskal-Wallis test was used to reveal the statistical difference in therapeutic efficacy among the groups.

RESULTS

The CRSsNP group showed nasal mucosal glandular density of '+++/++' with minimal Eos infiltration, and 94% achieved control. The nECRSwNP group exhibited atypical glandular hyperplasia and Eos infiltration, with 22% achieving complete control, 51% partial control, and 27% no control. The ECRSwNP group had significant Eos infiltration '++/+++' and reduced glands, with 93% showing uncontrolled conditions.

CONCLUSIONS AND SIGNIFICANCE

The findings suggest that extensive Eos infiltration and ECP secretion contribute to glandular and epithelial damage, reducing lysozyme and IgA production. These changes may promote chronic inflammation and increase the likelihood of nasal polyp recurrence.

Enhanced IL-37-IL-1R8 axis is negatively associated with inflammatory and clinical severity of chronic rhinosinusitis with nasal polyps

Background

The importance of IL-37 and downstream signal in the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP) demanding further investigation.

Objective

We sought to address the potential importance of the IL-37-IL-1R8 axis in regulating inflammatory response in patients with CRSwNP.

Methods

Nasal polyp (NP) tissues and control sinonasal tissues were obtained from adult CRSwNP, chronic rhinosinusitis without nasal polyps patients and healthy control subjects. The mRNA and protein levels of IL-37 and IL-1R8 in nasal tissues were examined by using quantitative PCR, immunohistochemical staining, and immunoblotting. In addition, the regulation of IL-1R8 expression was evaluated in human nasal epithelial cells (HNECs) in the presence of different stimuli.

Results

The mRNA and protein levels of IL-37 and IL-1R8 were significantly elevated in nasal polyps compared with that in control tissues. IL-37 and IL-1R8 were mainly distributed in the epithelial layer and lamina propria of tissues. IL-1R8 mRNA level in nasal polys was negatively associated with eosinophil and neutrophil infiltration, as well as endoscopic score and computed tomography score. Moreover, the mRNA expression of IL-1R8 in HNECs was significantly increased by toll-like receptor agonists, but significantly inhibited by proinflammatory cytokines, which can be rescued by using steroid (DEX).

Conclusion

Our findings showed that enhanced IL-37-IL-1R8 axis in NP tissues was negatively associated with inflammatory and clinical severity of CRSwNP patients, which could be considered as a future therapeutic target in CRSwNP patients.

Immunopathologic Role of Eosinophils in Eosinophilic Chronic Rhinosinusitis

Chronic rhinosinusitis (CRS) is a diverse chronic inflammatory disease of the sinonasal mucosa. CRS manifests itself in a variety of clinical and immunologic patterns. The histological hallmark of eosinophilic CRS (ECRS) is eosinophil infiltration. ECRS is associated with severe disease severity, increased comorbidity, and a higher recurrence rate, as well as thick mucus production. Eosinophils play an important role in these ECRS clinical characteristics. Eosinophils are multipotential effector cells that contribute to host defense against nonphagocytable pathogens, as well as allergic and nonallergic inflammatory diseases. Eosinophils interact with Staphylococcus aureus, Staphylococcal enterotoxin B, and fungi, all of which were found in the tissue of CRS patients. These interactions activate Th2 immune responses in the sinonasal mucosa and exacerbate local inflammation. Activated eosinophils were discovered not only in the tissue but also in the sinonasal cavity secretion. Eosinophil extracellular traps (EETs) are extracellular microbes trapping and killing structures found in the secretions of CRS patients with intact granule protein and filamentous chromatic structures. At the same time, EET has a negative effect by causing an epithelial barrier defect. Eosinophils also influence the local tissue microenvironment by exchanging signals with other immune cells and structural cells. As a result, eosinophils are multifaceted leukocytes that contribute to various physiologic and pathologic processes of the upper respiratory mucosal immune system. The goal of this review is to summarize recent research on the immunopathologic properties and immunologic role of eosinophils in CRS.

Age-Related Increase of Collagen/Fibrin Deposition and High PAI-1 Production in Human Nasal Polyps

Objective: Our previous studies showed an age-related increased prevalence of nasal polyps (NP) and reduced production of S100A8/9 in elderly patients with chronic rhinosinusitis with NP (CRSwNP). In this study, we investigated an unbiased age-related gene expression profile in CRSwNP subjects and healthy controls, and further identified the differences in their tissue remodeling. Methods: Microarrays using NP and uncinate tissues from health controls (elderly, age ≥65 vs. non-elderly, age 18-49) were performed, and differentially regulated genes were analyzed. Quantitative real-time PCR (qPCR), Immunostaining, Periodic acid-Schiff (PAS), trichrome staining, Western blot, and ELISA were performed for further investigation. Results: Microarrays identified differentially expressed genes according to disease and age; 278 in NP vs. controls, 75 in non-elderly NP vs. non-elderly controls, and 32 in elderly NP vs. elderly controls. qPCR confirmed that the PLAT gene was downregulated and the SERPINB2 gene upregulated in NP vs. controls. The serous glandular cell-derived antimicrobial protein/peptide-related genes such as BPIFB3, BPIFB2, LPO, and MUC7 were remarkably reduced in NP, regardless of age. SERPINE1 gene (plasminogen activator inhibitor-1, PAI-1) expression was significantly increased in elderly NP versus elderly controls. IHC and western blot confirmed significantly decreased production of MUC7 and LPO in NP versus controls. There was a trend of age-related reduction of submucosal gland cells in normal controls. Trichrome and immunofluorescence staining demonstrated an age-related increase of collagen and fibrin deposition in NP, consistent with increased PAI-1 production. Conclusion: This study demonstrated age-related differential glandular remodeling patterns and fibrosis in NP and normal controls. PAI-1 expression was significantly increased in elderly NP versus elderly controls, suggesting PAI-1 as a potential treatment target in elderly NP.

Transcriptomic and Lipidomic Profiles in Nasal Polyps of Glucocorticoid Responders and Non-Responders: Before and After Treatment

Background: The pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP) and mechanisms underlying different responses to systemic glucocorticoids (GC) remain unclear. The major aim of this study was to explore the transcriptomic and oxidative lipidomic signatures and the effects of GC in patients with different clinical responses.

Methods: Nasal polyp biopsies were obtained before and after 14-day oral GC treatment from 16 patients with CRSwNP, and normal nasal mucosa specimens were collected from 12 control subjects. RNA sequencing and oxidative lipidomics were performed, and differential gene expression analysis was conducted in the Responder and Non-responder groups at baseline and after treatment.

Results: In the Responder group, GC significantly improved clinical symptoms and reduced tissue eosinophil infiltration. Meanwhile, GC led to a pronounced transcriptomic reversion with robust suppression of inflammatory responses and abnormal metabolism of extracellular matrix, as well as restoration of cilia function. However, non-responders were mainly characterized by epithelial hyperplasia and keratinization, with much less transcriptomic improvement after GC treatment. Higher expression of type 2 inflammatory molecules (CCL13, IGHE, CCL18, CCL23, CCR3, and CLC) with lower levels of LACRT, PPDPFL, DES, C6, MUC5B, and SCGB3A1 were related to a stronger clinical response to GC. Besides decreased prostaglandins and increased leukotrienes, increased dysregulation in other oxylipid mediators derived from polyunsaturated fatty acids was determined in nasal polyps, which was ameliorated by GC treatment.

Conclusion: Systemic GC exert anti-inflammatory effects, improve tissue remodeling, restore cilia function, and ameliorate dysregulation of oxylipid mediator pathway in CRSwNP. GC-responders exhibited different transcriptomic signatures from non-responders.

Inflammatory molecular endotypes of nasal polyps derived from Caucasian and Japanese populations

BACKGROUND

Emerging evidence suggests that chronic rhinosinusitis with nasal polyps (CRSwNP) is a highly heterogeneous disease with disparate inflammatory characteristics between different racial groups and geographies. Little is known currently about possible distinguishing factors underlying these inflammatory differences.

OBJECTIVE

To interrogate for differences between Caucasian and Japanese CRSwNP disease using whole transcriptome and single-cell RNA gene expression profiling of nasal polyps (NPs).

METHODS

We performed whole transcriptome RNA sequencing (RNA-seq) with endotype stratification of NPs from 8 Caucasian (residing in USA) and 9 Japanese (residing in Japan) patients. Reproducibility was confirmed by qPCR in an independent validation set of 46 Caucasian and 31 Japanese patients. Single-cell RNA-seq stratified key cell types for contributory transcriptional signatures.

RESULTS

Unsupervised clustering analysis identified two major endotypes present within both NP cohorts, which have previously been reported at the cytokine level: 1) type 2 endotype and 2) non-type 2 endotype. Importantly, there was a statistically significant difference in the proportion of these endotypes between these geographically distinct NP subgroups (p = 0.03). Droplet-based single-cell RNA sequencing further identified prominent type 2 inflammatory transcript expression: C-C motif chemokine ligand 13 (CCL13) and CCL18 in M2 macrophages, as well as cystatin SN (CST1) and CCL26 in basal, suprabasal, and secretory epithelial cells.

CONCLUSION

NPs from both racial groups harbor the same two major endotypes, which we determine are present in differing ratios between each cohort with CRSwNP disease. Distinct inflammatory and epithelial cells contribute to the type 2 inflammatory profiles observed.

Impact of type 2 targeting biologics on acute exacerbations of chronic rhinosinusitis

Background: Acute exacerbations of chronic rhinosinusitis (AECRS) are associated with significant morbidity and decreased quality of life. There are sparse data assessing the real-world impact of biologics on AECRS. Objectives: We sought to determine the impact of type 2-targeting biologics on the frequency of medication use for AECRS episodes. Methods: Antibiotic and/or systemic corticosteroid courses for AECRS were identified in a retrospective study from November 2015 to February 2020, at a single academic health system. The estimated yearly rates for antibiotic and corticosteroid courses were evaluated before and after initiation of type 2 biologics. Results: One-hundred and sixty-five patients with chronic rhinosinusitis (CRS) had received either omalizumab (n = 12), mepolizumab (n = 42), benralizumab (n = 44), dupilumab (n = 61), or reslizumab (n = 6). Seventy percent had CRS with nasal polyps, and 30% had CRS without nasal polyps. All the patients had asthma. When all the biologics were combined, the estimated yearly rate for antibiotics for AECRS decreased from 1.34 (95% confidence interval [CI], 1.12-1.59) to 0.68 (95% CI, 0.52-0.88) with biologic use (49% reduction, p < 0.001). Those with frequent AECRS (three or more courses of antibiotics in the 1 year before biologic use) had a larger degree of reduction, with an estimated yearly rate of 4.15 (95% CI, 3.79-4.55) to 1.58 (95% CI, 1.06-2.35) with biologic use (n = 27; 62% reduction; p < 0.001). Within the total cohort, the estimated yearly rate for systemic corticosteroids for AECRS decreased from 1.69 (95% CI, 1.42-2.02) to 0.68 (95% CI, 0.53-0.88) with biologic use (60% reduction; p < 0.001). Conclusion: Type 2-targeting biologics reduced medication use for AECRS. This suggested that biologics may be a therapeutic option for patients with frequent AECRS.

Changes in saliva proteins in cows with mastitis: A proteomic approach

This study aimed to evaluate the possible saliva proteome changes in cows with mastitis using a Tandem Mass Tags (TMT) proteomics approach. For this purpose, the salivary proteomes from healthy cows and cows with mastitis were analysed, and their serum proteomes were also studied for comparative purposes. A total of eight saliva and serum paired samples for each group were used for the proteomic study, and eight additional samples for each group were analysed in the analytical and overlap performance studies. In saliva samples, 2192 proteins were identified, being sixty-three differentially modulated in mastitis. In serum, 1299 proteins were identified, being twenty-nine differentially modulated in mastitis. Gamma glutamyl transferase (γGT) in saliva and serum amyloid A (SAA) were validated by commercially available automated assays. In conclusion, there are changes in protein expression and metabolic pathways in saliva and serum proteomes of cows with mastitis, showing different response patterns but complementary information.

Reduced Expression of Antimicrobial Protein Secretory Leukoprotease Inhibitor and Clusterin in Chronic Rhinosinusitis with Nasal Polyps

Introduction

Antimicrobial peptides and proteins (AMPs) constitute the first line of defense against pathogenic microorganisms in the airway. The association between AMPs and chronic rhinosinusitis with nasal polyps (CRSwNP) requires further investigations. This study is aimed at investigating the expression and regulation of major dysregulated AMPs in the nasal mucosa of CRSwNP.

Methods

The expression of AMPs was analyzed in nasal tissue from patients with eosinophilic (E) CRSwNP and nonECRSwNP and healthy subjects using RNA sequencing. The 10 most abundant AMPs expressed differentially in CRSwNP patients were verified by real-time PCR, and of these, the expression and regulation of secretory leukoprotease inhibitor (SLPI) and clusterin (CLU) were investigated further.

Results

The 10 most abundant AMPs expressed differentially in CRSwNP compared to healthy control, regardless of subtypes, included BPIFA1, BPIFB1, BPIFB2, CLU, LTF, LYZ, and SLPI, which were downregulated, and S100A8, S100A9, and HIST1H2BC, which were upregulated. ELISA and immunofluorescence confirmed the decreased expression of SLPI and CLU levels in CRSwNP. SLPI is expressed in both nasal epithelial cells and glandular cells, whereas CLU is mainly expressed in glandular cells. AB/PAS staining further demonstrated that both SLPI and CLU were mainly produced by mucous cells in submucosal glands. Furthermore, the numbers of submucosal glands were significantly decreased in nasal polyp tissue of CRSwNP compared to nasal tissue of controls. SLPI was downregulated by TGF-β1 and IL-4 in cultured nasal tissues in vitro, while CLU expression was inhibited by TGF-β1. Glucocorticoid treatment for 2 weeks significantly increased the expression of all downregulated AMPs, but not LYZ. Additionally, budesonide significantly increased the expression of SLPI and CLU in cultured nasal tissues.

Conclusion

The expression of major antimicrobial proteins is significantly decreased in nasal tissue of CRSwNP. The expression of SLPI and CLU is correlated with the numbers of submucosal glands and regulated by inflammatory cytokines and glucocorticoids.

Predictive significance of arachidonate 15-lipoxygenase for eosinophilic chronic rhinosinusitis with nasal polyps

Background

Eosinophilic chronic rhinosinusitis with nasal polyps (ECRSwNP) exhibits a poorer outcome compared with non-eosinophilic chronic rhinosinusitis with nasal polyps (nonECRSwNP), so it is significant to identify effective markers to differentiate ECRSwNP in guiding the treatment strategies of these patients. Although arachidonate 15-lipoxygenase (ALOX15) is positioned as a marker of eosinophilic inflammation, its study in differentiating ECRSwNP has not been reported. The aim of this study is to assess the potential of ALOX15 in distinguishing and predicting ECRSwNP.

Methods

Forty-eight patients with chronic rhinosinusitis with nasal polyps (CRSwNP), including 30 ECRSwNP and 18 nonECRSwNP patients, were enrolled. ALOX15 mRNA level was determined in polyps by real-time polymerase chain reaction (RT-PCR). The patients’ baseline characteristics were evaluated and analyzed for correlations with ALOX15. Receiver operating characteristic (ROC) curve was used to assess the predictive significance of the potential predictors for ECRSwNP.

Results

ALOX15 mRNA level was significantly higher in ECRSwNP patients than in nonECRSwNP patients (P < 0.001). ALOX15 mRNA was significantly correlated with tissue and blood eosinophil percentages (r = 0.565, P < 0.001 and r = 0.395, P = 0.006), olfaction scores (r = 0.400, P = 0.005), total visual analogue scale (VAS) symptom scores (r = 0.383, P = 0.007), ethmoid/maxillary sinus (E/M) ratio (r = 0.463, P = 0.001), and endoscopy scores (r = 0.409, P = 0.004). Logistic regression analysis showed ALOX15 mRNA level and percentage of blood eosinophils to be predictive factors for ECRSwNP (P = 0.004 and P = 0.036, respectively). ROC curve indicated ALOX15 to have high predictive accuracy for ECRSwNP (area under the curve (AUC) = 0.909), which was further improved by combination of ALOX15 with percentage of blood eosinophils (AUC = 0.933).

Conclusions

The relative ALOX15 mRNA level alone or in combination with blood eosinophils might be a reliable biomarker for predicting a diagnosis of ECRSwNP.

Bioinformatics Analysis and Identification of Underlying Biomarkers Potentially Linking Allergic Rhinitis and Asthma

Background

Rhinitis is the most common clinical manifestation of allergy, affecting more than 400 million people around the world. Rhinitis increases the risk of developing bronchial hyper-responsiveness and asthma. Previous studies have shown that rhinitis is closely related with the physiology, pathology, and pathogenesis of asthma. We analyzed co-expressed genes to explore the relationships between rhinitis and asthma and to find biomarkers of comorbid rhinitis and asthma.

Material/Methods

Asthma- and rhinitis-related differentially-expressed genes (DEGs) were identified by bioinformatic analysis of GSE104468 and GSE46171 datasets from the Gene Expression Omnibus (GEO) database. After assessment of Gene Ontology (GO) terms and pathway enrichment for DEGs, a protein–protein interaction (PPI) network was conducted via comprehensive target prediction and network analyses. We also evaluated co-expressed DEGs and corresponding predicted miRNAs involved in the developing process of rhinitis and asthma.

Results

We identified 687 and 1001 DEGs in bronchial and nasal epithelia samples of asthma patients, respectively. For patients with rhinitis, we found 245 DEGs. The hub-genes of PAX6, NMU, NTS, NMUR1, PMCH, and KRT6A may be associated with rhinitis, while CPA3, CTSG, POSTN, CLCA1, HDC, and MUC5B may be involved in asthma. The co-expressed DEGs of BPIFA1, CCL26, CPA3, and CST1, together with corresponding predicted miRNAs (e.g., miR-195-5p and miR-125a-3p) were found to be significantly correlated with rhinitis and asthma.

Conclusions

Rhinitis and asthma are related, and there are significant correlations of BPIFA1, CCL26, CPA3, and CST1 genes with novel biomarkers involved in the comorbidity of rhinitis and asthma.

Chinese Society of Allergy and Chinese Society of Otorhinolaryngology-Head and Neck Surgery Guideline for Chronic Rhinosinusitis

The current document is based on a consensus reached by a panel of experts from the Chinese Society of Allergy and the Chinese Society of Otorhinolaryngology-Head and Neck Surgery, Rhinology Group. Chronic rhinosinusitis (CRS) affects approximately 8% of Chinese adults. The inflammatory and remodeling mechanisms of CRS in the Chinese population differ from those observed in the populations of European descent. Recently, precision medicine has been used to treat inflammation by targeting key biomarkers that are involved in the process. However, there are no CRS guidelines or a consensus available from China that can be shared with the international academia. The guidelines presented in this paper cover the epidemiology, economic burden, genetics and epigenetics, mechanisms, phenotypes and endotypes, diagnosis and differential diagnosis, management, and the current status of CRS in China. These guidelines-with a focus on China-will improve the abilities of clinical and medical staff during the treatment of CRS. Additionally, they will help international agencies in improving the verification of CRS endotypes, mapping of eosinophilic shifts, the identification of suitable biomarkers for endotyping, and predicting responses to therapies. In conclusion, these guidelines will help select therapies, such as pharmacotherapy, surgical approaches and innovative biotherapeutics, which are tailored to each of the individual CRS endotypes.

Key role of the epithelium in chronic upper airways diseases

The respiratory epithelium of the upper airways is a first-line defence against inhaled irritants, pathogens and allergens. It ensures a physical barrier provided by apical junctions and mucociliary clearance to avoid excessive activation of the immune system. The epithelium also forms a chemical and immunological barrier, extensively equipped to protect the airways against external aggressions before the adaptive immune system is required. Under normal circumstances, the epithelium is capable of recovering rapidly after damage. This manuscript reviews these main properties of the upper airway epithelium as well as its reported impairments in chronic inflammatory diseases. The knowledge on normal epithelial functions and their dysregulation in upper airway diseases should help to design new epithelial-targeted treatments.

The effect of BPIFA1/SPLUNC1 genetic variation on its expression and function in asthmatic airway epithelium

Bacterial permeability family member A1 (BPIFA1), also known as short palate, lung, and nasal epithelium clone 1 (SPLUNC1), is a protein involved in the antiinflammatory response. The goal of this study was to determine whether BPIFA1 expression in asthmatic airways is regulated by genetic variations, altering epithelial responses to type 2 cytokines (e.g., IL-13). Nasal epithelial cells from patients with mild to severe asthma were collected from the National Heart, Lung, and Blood Institute Severe Asthma Research Program centers, genotyped for rs750064, and measured for BPIFA1. To determine the function of rs750064, cells were cultured at air-liquid interface and treated with IL-13 with or without recombinant human BPIFA1 (rhBPIFA1). Noncultured nasal cells with the rs750064 CC genotype had significantly less BPIFA1 mRNA expression than the CT and TT genotypes. Cultured CC versus CT and TT cells without stimulation maintained less BPIFA1 expression. With IL-13 treatment, CC genotype cells secreted more eotaxin-3 than CT and TT genotype cells. Also, rhBPIFA1 reduced IL-13-mediated eotaxin-3. BPIFA1 mRNA levels negatively correlated with serum IgE and fractional exhaled nitric oxide. Baseline FEV1% levels were lower in the asthma patients with the CC genotype (n = 1,016). Our data suggest that less BPIFA1 in asthma patients with the CC allele may predispose them to greater eosinophilic inflammation, which could be attenuated by rhBPIFA1 protein therapy.

Excessive periostin expression and Th2 response in patients with nasal polyps: association with asthma

Background

Periostin has been shown to be upregulated in chronic rhinosinusitis with nasal polyps (CRSwNP), especially in the CRSwNP patients with asthma. However, the underlying mechanism that how periostin contributes to the polyp genesis remains unclear.

Methods

In this study, we collected 63 CRSwNP patients' nasal polyps (NPs) and 25 control subjects' uncinated tissues. The expressions of periostin, thymic stromal lymphopoietin (TSLP), and other proinflammatory cytokines were examined using IHC staining, qRT-PCR, Western blot (WB), ELISA and FACS. The eosinophil infiltration, phenotype profiles and clinical characteristics of 2 NP subtypes (eosinophilic and non-eosinophilic) were evaluated. We examined the effects and mechanisms of periostin on human nasal epithelial cells cultured at air-liquid interface (ALI).

Results

The expressions of periostin in NPs with asthma were higher than without asthma and the control nasal mucosa and positively associated with the TSLP (P<0.05). And the periostin levels was positively associated with the basement membrane thickness, goblet cell hyperplasia and tissue eosinophilia polyp tissues, as well as the clinical parameters (computed tomography scores, polyp size, and polyp recurrence after endoscopic surgery). In vitro experiments show that type 2 T-helper (Th2) cytokines interleukin-4 (IL-4), IL-13 and TGF-β1 stimulates epithelial cells derived from polyp tissues to produce periostin through ERK and STAT6 signal pathways (P<0.05). Autocrine or recombinant periostin activates epithelial cells to produce TSLP via NF-κB signal pathways (P<0.05). The supernatant of periostin-treated epithelial cells activates dendritic cells (DCs), which subsequently induce naïve T cells to differentiate into Th2 cells and express IL-4 and IL-13.

Conclusions

Our findings indicate periostin may play an important role in the polyp genesis, which can be considered as a therapeutic target for the management of CRSwNP.

Current understanding of allergic fungal rhinosinusitis

Studying the pathophysiology of allergic fungal rhinosinusitis (AFRS) has proved challenging. While this clinical entity is easily distinguishable based on the clinical criteria set forth by Bent and Kuhn twenty-five years ago, studies examining type 2 inflammatory profiles in AFRS can make it seem more alike other CRS subtypes than it is different. Still, evolving research seems to clearly delineate this subtype from others in CRS. This review will critically evaluate the evolution of research examining the pathophysiology of AFRS and will conclude with a summary of the special considerations in the management of this fascinating disease.

High frequency of macrophages expressing elevated level of CD80, PD-Ls and TLR1 in nasal polyps of CRS patients

Identification of the association between tissue biomarkers, their surrogates in blood and clinical features, could provide new diagnostic tools and facilitate adequate choices of therapeutic interventions for selected patients suffering from CRS. The aim of present study was the assessment of macrophages in the polyp tissue and monocytes in the peripheral blood in the course of CRSwNP, and their functional immunophenotype. We analyzed 31 patients with CRSwNP. Nasal mucosa tissue was obtained via functional endoscopic sinus surgery (FESS). The control group included 10 patients with deviated nasal septum (DNS). Fluorochrome stained cells were proceed to acquisition using FACS Canto flow cytometer, and the results were analyzed using the software FACS Diva. In our study, we observed a significantly higher level of CD80, CD274, CD273 and TLR1 in nasal polyps compared to blood samples from patients with CRSwNP. This finding may suggest the importance of the PD-1 pathway as a therapeutic target in CRS and an important role for TLR1 in nasal polyp formation and maintenance. Our results may provide some insight into potential future targets of recurrent nasal polyp treatment and contribute to a better understanding of the inflammatory process in Chronic Rhinosinusitis.

Notch-1 signaling activation sustains overexpression of interleukin 33 in the epithelium of nasal polyps

BACKGROUND

Alterations in the nasal epithelial barrier homeostasis and increased interleukin 33 (IL-33) expression contribute to the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP).

AIMS

As Notch-1 signaling is crucial in repair processes of mucosa, the current study assessed Notch-1/Jagged-1 signaling and IL-33 in the epithelium of nasal polyps biopsies from allergic (A-CRSwNP; n = 9) and not allergic (NA-CRSwNP; n = 9) subjects by immunohistochemistry. We also assessed, in a model of nasal epithelial cells, the effects of stimulation of Notch-1 with Jagged-1 on the expression of IL-33 (by flow cytometry, immunofluorescence, and immunocytochemistry), Jagged-1 (by flow cytometry), and p-CREB transcription factor (by western blot analysis).

RESULTS

Ex vivo (a) in normal epithelium, the expression of Notch-1 and IL-33 were higher in NA-CRSwNP than in A-CRSwNP; (b) in metaplastic epithelium, the expression of Notch-1, Jagged-1, and IL-33 were higher in NA-CRSwNP than in A-CRSwNP; (c) in hyperplastic epithelium, the expression of Notch-1, Jagged-1, and IL-33 were higher in A-CRSwNP than in NA-CRSwNP; and (d) in basal epithelial cells, no differences were observed in the expression of Jagged-1, IL-33, and Notch-1. The expression of Notch-1 significantly correlated with the expression of IL-33. In vitro, stimulation of Notch-1 with Jagged-1 induced the expression of (a) Jagged-1; (b) IL-33; and (c) p-CREB transcription factor. The inhibitor of Notch-1, DAPT, reduced all the effects of Jagged-1 on nasal epithelial cells.

CONCLUSIONS

The data herein provided support, for the first time, a putative role of Notch-1/Jagged-1 signaling in the overexpression of IL-33 in the epithelium of nasal polyps from patients with CRSwNP.

Crystal structure of the mouse innate immunity factor bacterial permeability-increasing family member A1

Bacterial permeability-increasing family member A1 (BPIFA1) is an innate immunity factor and one of the most abundantly secreted proteins in the upper airways. BPIFA1 is multifunctional, with antimicrobial, surfactant and lipopolysaccharide-binding activities, as well as established roles in lung hydration. Here, the 2.5 Å resolution crystal structure of BPIFA1 from Mus musculus (mBPIFA1) is presented and compared with those of human BPIFA1 (hBPIFA1) and structural homologs. Structural distinctions between mBPIFA1 and hBPIFA1 suggest potential differences in biological function, including the regulation of a key pulmonary ion channel.

Distinguishing Molecular Features of Allergic Fungal Rhinosinusitis

Objective

Allergic fungal rhinosinusitis (AFRS) is a clinical subtype of chronic rhinosinusitis with nasal polyps (CRSwNP), characterized by eosinophilic mucin, evidence of fungal elements within the mucin, fungal-specific type I hypersensitivity, and characteristic computed tomography findings. It remains controversial whether AFRS represents a disease with a unique pathophysiology from chronic rhinosinusitis or is merely a severe form of CRSwNP. The goal of this study was to identify molecular features unique to AFRS.

Study Design

Cross-sectional case-control.

Setting

Single academic tertiary referral institution.

Subjects and Methods

Subjects included 86 patients undergoing endoscopic sinus surgery: CRSwNP (n = 34), AFRS (n = 37), and healthy controls (n = 15). Pathway and correlation analyses were performed with whole-genome microarray data for study patients undergoing surgery for recalcitrant chronic rhinosinusitis. Our findings were confirmed with quantitative polymerase chain reaction and immunohistochemical studies.

Results

AFRS was uniquely characterized by a pronounced association with adaptive T helper 2–associated immune gene expression. AFRS exhibited altered expression of proteins associated with secretory salivary peptides—namely, histatin, a peptide with known antifungal activity in the oral cavity. Furthermore, the expression of histatins correlated negatively with that of type 2 inflammatory mediators. We confirm the decreased expression of histatins in AFRS when compared with CRSwNP by quantitative polymerase chain reaction and localized its expression to a submucosal cell population.

Conclusion

There exist clear molecular profiles that distinguish AFRS from CRSwNP. This divergence translates into an altered ability to control fungal growth and may in part explain some of the phenotypical differences between CRSwNP and AFRS.

Differential Hrd1 Expression and B-Cell Accumulation in Eosinophilic and Non-eosinophilic Chronic Rhinosinusitis With Nasal Polyps

Purpose

Hrd1 has recently emerged as a critical regulator of B-cells in autoimmune diseases. However, its role in the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP) remains largely unexplored. This study aimed to examine Hrd1 expression and B-cell accumulation and their possible roles in CRSwNP.

Methods

Quantitative real-time polymerase chain reaction, immunohistochemistry, enzyme-linked immunosorbent assay and Western blotting were used to assess gene and protein expression in nasal tissue extracts. Cells isolated from nasal tissues and peripheral blood mononuclear cells were characterized by flow cytometry. Local antibody production was measured in tissue extracts with a Bio-Plex assay. Additionally, changes in Hrd1 expression in response to specific inflammatory stimuli were measured in cultured dispersed polyp cells.

Results

Nasal polyps (NPs) from patients with eosinophilic CRSwNP (ECRS) had increased levels of Hrd1, B-cells and plasma cells compared with NPs from patients with non-eosinophilic CRSwNP (non-ECRS) or other control subjects (P < 0.05). The average Hrd1 levels in B-cells in NPs from ECRS patients were significantly higher than those from non-ECRS patients and control subjects (P < 0.05). NPs also contained significantly increased levels of several antibody isotypes compared with normal controls (P < 0.05). Interestingly, Hrd1 expression in cultured polyp cells from ECRS patients, but not non-ECRS patients, was significantly increased by interleukin-1β, lipopolysaccharide and Poly(I:C) stimulation, and inhibited by dexamethasone treatment (P < 0.05).

Conclusions

Differential Hrd1 expression and B-cell accumulation between the ECRS and non-ECRS subsets suggests that they can exhibit distinct pathogenic mechanisms and play important roles in NP.

The Role of Periostin in the Occurrence and Progression of Eosinophilic Chronic Sinusitis with Nasal Polyps

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a highly heterogeneous disease with different host defence responses. However, whether periostin and vascular endothelial growth factor (VEGF) are similarly impaired in patients with eosinophilic CRSwNP (ENP) and those with non-eosinophilic CRSwNP (nENP) remains unclear. We sought to evaluate the expression and possible modulation of periostin and VEGF, regulated on activation normal T expressed and secreted (RANTES) and eotaxin-2 in the polyp tissues from 30 patients with ENP and from 36 patients with nENP and in middle turbinate tissues from 12 control subjects. We found that ENP tissues exhibited a significantly increased expression of periostin and VEGF compared with tissues from patients with nENP and control subjects (P < 0.05, respectively). Accordingly, the expression of VEGF, RANTES, and eotaxin-2 in ENP fibroblasts was significantly up-regulated after stimulation with up-regulated periostin in vitro, but the expression of VEGF and RANTES was significantly inhibited by stimulation with down-regulated periostin. Our findings suggest that periostin might play an important role in the occurrence and progression of ENP and might be a potential therapeutic target.

Immunopathogenesis of Chronic Rhinosinusitis and Nasal Polyposis

Chronic rhinosinusitis (CRS) is a troublesome, chronic inflammatory disease that affects over 10% of the adult population, causing decreased quality of life, lost productivity, and lost time at work and leading to more than a million surgical interventions annually worldwide. The nose, paranasal sinuses, and associated lymphoid tissues play important roles in homeostasis and immunity, and CRS significantly impairs these normal functions. Pathogenic mechanisms of CRS have recently become the focus of intense investigations worldwide, and significant progress has been made. The two main forms of CRS that have been long recognized, with and without nasal polyps, are each now known to be heterogeneous, based on underlying mechanism, geographical location, and race. Loss of the immune barrier, including increased permeability of mucosal epithelium and reduced production of important antimicrobial substances and responses, is a common feature of many forms of CRS. One form of CRS with polyps found worldwide is driven by the cytokines IL-5 and IL-13 coming from Th2 cells, type 2 innate lymphoid cells, and probably mast cells. Type 2 cytokines activate inflammatory cells that are implicated in the pathogenic mechanism, including mast cells, basophils, and eosinophils. New classes of biological drugs that block the production or action of these cytokines are making important inroads toward new treatment paradigms in polypoid CRS.

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.

Interleukin-13 Inhibits Lipopolysaccharide-Induced BPIFA1 Expression in Nasal Epithelial Cells

Short palate, lung, and nasal epithelium clone 1 (SPLUNC1) protein is expressed in human nasopharyngeal and respiratory epithelium and has demonstrated antimicrobial activity. SPLUNC1 is now referred to as bactericidal/permeability-increasing fold containing family A, member 1 (BPIFA1). Reduced BPIFA1 expression is associated with bacterial colonization in patients with chronic rhinosinusitis with nasal polyps (CRSwNP). Interleukin 13 (IL-13), predominately secreted by T helper 2 (T_H2) cells, has been found to contribute to airway allergies and suppress BPIFA1 expression in nasal epithelial cells. However, the molecular mechanism of IL-13 perturbation of bacterial infection and BPIFA1 expression in host airways remains unclear. In this study, we found that lipopolysaccharide (LPS)-induced BPIFA1 expression in nasal epithelial cells was mediated through the JNK/c-Jun signaling pathway and AP-1 activation. We further demonstrated that IL-13 downregulated the LPS-induced activation of phosphorylated JNK and c-Jun, followed by attenuation of BPIFA1 expression. Moreover, the immunohistochemical analysis showed that IL-13 prominently suppressed BPIFA1 expression in eosinophilic CRSwNP patients with bacterial infection. Taken together, these results suggest that IL-13 plays a critical role in attenuation of bacteria-induced BPIFA1 expression that may result in eosinophilic CRSwNP.

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

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

Increased IL-21 expression in chronic rhinosinusitis with nasalpolyps

BACKGROUND

IL-21 is a key cytokine for regulating B cell immunity, which is involved in several inflammatory conditions. This study sought to define a role for IL-21 in activated B lymphocytes and enhanced tissue eosinophilia in NP tissues during the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP).

METHODS

NP and uncinate process tissues were collected from 64 CRSwNP patients, 25 CRSsNP patients, and 29 control subjects. IL-21 expression was examined using IHC staining, qRT-PCR, flow cytometry, and ELISA, and its clinical implication was evaluated. Moreover, the effects of IL-21 on B cell differentiation and Ig production in cultured NP cells were examined in vitro.

RESULTS

The mRNA and protein levels of IL-21 were significantly increased in polyp tissues compared with control tissues (P < 0.05). Polyp IL-21 level was significantly associated with polyp size, tissue eosinophilia and asthma comorbidity, and recurrence after surgery (P < 0.05). Both Th1 and Th17 cells were the main cellular sources of IL-21 in polyp tissues. The percentage of IL-21(+) CD4(+) cells was significantly higher in polyp tissues compared with control tissues and matched PBMCs (P < 0.01). Accordingly, the percentage of CD19(+) CD20(+/-) CD38(high) cells was significantly higher in polyp tissues compared with control tissues (P < 0.01). Moreover, recombinant IL-21 significantly increased the percentage of CD19(+) CD20(+/-) CD38(high) cells (plasmablasts) and IgG and IgA production in cultured NP cells in vitro (P < 0.05).

CONCLUSION AND CLINICAL RELEVANCE

Increased IL-21 level in polyp tissues was associated with disease severity, local B cell activation, and immunoglobulin production, suggesting that IL-21 might play an important role in promoting persistent mucosal inflammation in CRSwNP patients.

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.

Pathogenesis of nasal polyposis

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a complex inflammatory condition that affects a large proportion of the population world-wide and is associated with high cost of management and significant morbidity. Yet, there is a lack of population-based epidemiologic studies using current definitions of CRSwNP, and the mechanisms that drive pathogenesis in this disease remain unclear. In this review, we summarize the current evidence for the plethora of factors that likely contribute to CRSwNP pathogenesis. Defects in the innate function of the airway epithelial barrier, including diminished expression of antimicrobial products and loss of barrier integrity, combined with colonization by fungi and bacteria likely play a critical role in the development of chronic inflammation in CRSwNP. This chronic inflammation is characterized by elevated expression of many key inflammatory cytokines and chemokines, including IL-5, thymic stromal lymphopoietin and CCL11, that help to initiate and perpetuate this chronic inflammatory response. Together, these factors likely combine to drive the influx of a variety of immune cells, including eosinophils, mast cells, group 2 innate lymphoid cells and lymphocytes, which participate in the chronic inflammatory response within the nasal polyps. Importantly, however, future studies are needed to demonstrate the necessity and sufficiency of these potential drivers of disease in CRSwNP. In addition to the development of new tools and models to aid mechanistic studies, the field of CRSwNP research also needs the type of robust epidemiologic data that has served the asthma community so well. Given the high prevalence, costs and morbidity, there is a great need for continued research into CRS that could facilitate the development of novel therapeutic strategies to improve treatment for patients who suffer from this disease.

Molecular mechanisms of nasal epithelium in rhinitis and rhinosinusitis

Allergic rhinitis, nonallergic rhinitis, and chronic rhinosinusitis are multifactorial upper airway diseases with high prevalence. Several genetic and environmental factors are proposed to predispose to the pathogenesis of the inflammatory upper airway diseases. Still, the molecular mechanisms leading toward the onset and progression of upper airway diseases are largely unknown. The upper airway epithelium has an important role in sensing the environment and regulating the inhaled air. As such, it links environmental insults to the host immunity. Human sinonasal epithelium serves as an excellent target for observing induced early-phase events, in vivo, and with a systems biological perspective. Actually, increasing number of investigations have provided evidence that altered homeostasis in the sinonasal epithelium might be important in the chronic upper airway inflammation.

Corticosteroid treatment regulates mucosal remodeling in chronic rhinosinusitis with nasal polyps

OBJECTIVES/HYPOTHESIS

To investigate the effect of oral plus intranasal corticosteroid (CS) treatment on nasal polyp (NP) mucosa remodeling from patients with severe chronic rhinosinusitis with nasal polyps (CRSwNP).

STUDY DESIGN

Case series, retrospective study.

METHODS

Patients (n = 18) with severe CRSwNP were treated with oral prednisone for 2 weeks and intranasal budesonide for 12 weeks. NP biopsies were obtained from patients biopsies before (w0) and after 2 weeks (w2) and 12 weeks (w12) of CS treatment. Matrix metalloprotease 1 (MMP-1), MMP-2, MMP-7, MMP-9, and tissue inhibitor of metalloprotease type 1 (TIMP-1) expression was evaluated by immunohistochemistry in cell and tissue structures. Epithelial damage, eosinophil infiltration, and collagen content were also examined in NP tissues before and after CS treatment.

RESULTS

Compared to w0: 1) oral plus intranasal CS significantly (P < .01) increased presence of submucosal glands at w2, decreased epithelial cell hyperplasia at w12, and decreased tissue eosinophilia at w2 and w12; 2) CS treatment significantly (P < .05) increased immunoreactivity for MMP-1 and MMP-2 in the epithelium at w2, but decreased immunoreactivity for MMP-9 in the epithelium at w2 and w12; 3) at w12, CS significantly (P < .05) reduced MMP-9 immunoreactive positivity and intensity in the extracellular matrix, while increasing total collagen amount in the extracellular matrix; and 4) CS treatment significantly (P < .01) reduced the number of eosinophils and their MMP and TIMP-1 immunoreactive expression.

CONCLUSIONS

CS treatment modulates NP mucosa remodeling, particularly by promoting epithelial repair, regulating tissue remodeling markers, increasing total collagen content, and reducing tissue eosinophil infiltration.

LEVEL OF EVIDENCE

4

Eosinophilic chronic rhinosinusitis in East Asians

Chronic rhinosinusitis (CRS) is a common disease worldwide, with a prevalence rate of 5%-15% in the general population. CRS is currently classified into two types: CRS with and without nasal polyps. CRS may also be divided into eosinophilic CRS (ECRS) and non-ECRS subtypes based on the presence of tissue eosinophilic infiltration or not. There are significant geographic and ethnic differences in the tissue eosinophilic infiltration, which is predominant in Western white patients and less common in East Asians, despite an increasing tendency for its prevalence in East Asia countries. ECRS differs significantly from non-ECRS in clinical characteristics, treatment outcomes and strategies, and underlying pathogenic mechanisms. ECRS commonly demonstrates more severe symptoms, polyp diseases with a higher incidence of bilateral polyps and sinonasal diseases on computed tomography, and the increase in blood eosinophils. ECRS is considered a special and recalcitrant subtype of CRS, commonly with poor treatment outcomes compared to non-ECRS. The differentiation of specific subtypes and clinical features of CRS will be important for developing novel treatment strategies and improving treatment outcomes for individual phenotypes of CRS. This review discusses clinical features, diagnosis, treatment and prognosis of ECRS in East Asians.