Multiple gene expression profiling suggests epithelial dysfunction in polypoid chronic rhinosinusitis

Oncostatin M Contributes to Airway Epithelial Cell Dysfunction in Chronic Rhinosinusitis with Nasal Polyps

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a typical type-2 inflammation involving several cytokines and is associated with epithelial cell dysfunction. Oncostatin M (OSM) (belonging to the interleukin(IL)-6 family) could be a key driver of epithelial barrier dysfunction. Therefore, we investigated the presence of OSM and IL-6 and the expression pattern of tight junctions (TJs) in the nasal tissue of CRSwNP patients and controls using reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) and Western blotting. Then, their potential role in the epithelial barrier was evaluated in vitro in 27 different primary cultures of human nasal epithelial cells (HNECs) by measuring TJ expression and transepithelial electric resistance (TEER) with or without OSM or IL-6 (1, 10, and 100 ng/mL). The effect on ciliary beating efficiency was evaluated by high-speed videomicroscopy and on repair mechanisms with a wound healing model with or without OSM. OSM and IL-6 were both overexpressed, and TJ (ZO-1 and occludin) expression was decreased in the nasal polyps compared to the control mucosa. OSM (100 ng/mL) but not IL-6 induced a significant decrease in TJ expression, TEER, and ciliary beating efficiency in HNECs. After 24 h, the wound repair rate was significantly higher in OSM-stimulated HNECs at 100 ng/mL. These results suggest that OSM could become a new target for monoclonal antibodies.

Construction and analysis of a ceRNA network and patterns of immune infiltration in chronic rhinosinusitis with nasal polyps: based on data mining and experimental verification

Recent studies have revealed the significant role of the competing endogenous RNA (ceRNA) network in human diseases. However, systematic analysis of the ceRNA mechanism in chronic rhinosinusitis with nasal polyps (CRSwNP) is limited. In this study, we constructed a competitive endogenous RNA (ceRNA) network and identified a potential regulatory axis in CRSwNP based on bioinformatics analysis and experimental verification. We obtained lncRNA, miRNA, and mRNA expression profiles from the Gene Expression Omnibus. After analysis of CRSwNP patients and the control groups, we identified 565 DE-lncRNAs, 23 DE-miRNAs, and 1799 DE-mRNAs by the DESeq2 R package or limma R package. Enrichment analysis of 1799 DE-mRNAs showed that CRSwNP was associated with inflammation and immunity. Moreover, we identified 21 lncRNAs, 8 miRNAs and 8 mRNAs to construct the lncRNA-miRNA-mRNA ceRNA network. A potential MIAT/miR-125a/IRF4 axis was determined according to the degree and positive correlation between a lncRNA and its competitive endogenous mRNAs. The GSEA results suggested that IRF4 may be involved in immune cell infiltration. The validation of another dataset confirmed that MIAT and IRF4 were differentially expressed between the CRSwNP and control groups. The area under the ROC curve (AUC) of MIAT and IRF4 was 0.944. The CIBERSORT analysis revealed that eosinophils and M2 macrophages may be involved in the CRSwNP process. MIAT was correlated with dendritic cells and M2 macrophages, and IRF4 was correlated with dendritic cells. Finally, to validate the key genes, we performed in-silico validation using another dataset and experimental validation using immunohistochemistry, immunofluorescence, and Western blot. In summary, the constructed novel MIAT/miR-125a/IRF4 axis may play a critical role in the development and progression of CRSwNP. We believe that the ceRNA network and immune cell infiltration could offer further insight into novel molecular therapeutic targets for CRSwNP.

Exploring the role of nasal cytology in chronic rhinosinusitis

Objective

Characterising the eosinophilic profile represents the main step in chronic rhinosinusitis (CRS) endotyping. The aim of the study is to verify the correlation between different methods for tissue eosinophilia quantification.

Methods

33 CRS patients undergoing endoscopic sinus surgery and 30 controls undergoing non-CRS surgeries were enrolled. Blood venous sampling, nasal biopsy on uncinate process (UP), nasal cytology on inferior turbinate (IT) and middle meatus (MM) were performed.

Results

Differences in eosinophil count in blood (P=0.0001), UP (P<0.0001), IT (P = 0.01) and MM (P = 0.0006) were significant between CRS cases and controls. A weak correlation was found between UP and blood eosinophil count (r = 0.34, P = 0.006) and between UP and IT eosinophil count (r = 0.30, P = 0.017). Moderate correlation between UP and MM (r = 0.51, P < 0.0001) was shown. ROC analysis predicted eosinophilic CRS with an overall low sensitivity. Once allergic patients were excluded from the analysis, the sensitivity decreased for sampling on IT and increased for MM sampling.

Conclusions

This study suggests that MM cytology gives more accurate information on the degree of tissue eosinophilia. Replication in wide and unbiased cohorts is necessary to verify these results and define accurate thresholds.

Structural changes in the extracellular matrix after cross-linking of nasal polyp tissue

Chronic rhinosinusitis with nasal polyposis is a disease characterised by a mechanical dysfunction that facilitates anomalous growth of the nasal mucosa, due to its unique remodelling process. The development of procedures capable of interfering with this process is thus of the utmost importance. This study deals with the evaluation of the effects of cross-linking upon the nasal polyp tissue extracellular matrix. Six patients undergoing surgery for polypectomy were selected. The riboflavin/UVA collagen cross-linking technique was applied to the surface of epithelialised and de-epithelialised resected polyps of the intervention group. The control group polyps were not submitted to cross-linking procedures. Ultrathin polyp tissue sections (8 μm) were processed for immunofluorescence with mouse anti-type I collagen antibody and AlexaFluor 488 conjugated secondary antibody plus DAPI counterstaining, and analysed by confocal microscopy. The effect of riboflavin/UVA collagen cross-linking was visible on confocal fluorescence microscopy. Quantitative morphology was associated with fluorescence imaging analysis, and pixel density and brightness were evaluated. The surface of treated polyps exhibited a higher density of collagen fibres compared to control polyps, as could be observed both visually and through objective measurements of the fluorescent regions. The effect was enhanced on the surface of the de-epithelialised polyps. The higher density of collagen fibres exhibited by the de-epithelialised treated polyps demonstrates the feasibility of this technique in interfering with the remodelling process and the mechanical dysfunction found in chronic rhinosinusitis with nasal polyposis.

Expression, Distribution and Role of Aquaporins in Various Rhinologic Conditions

Aquaporins (AQPs) are water-specific membrane channel proteins that regulate cellular and organismal water homeostasis. The nose, an organ with important respiratory and olfactory functions, is the first organ exposed to external stimuli. Nose-related topics such as allergic rhinitis (AR) and chronic rhinosinusitis (CRS) have been the subject of extensive research. These studies have reported that mechanisms that drive the development of multiple inflammatory diseases that occur in the nose and contribute to the process of olfactory recognition of compounds entering the nasal cavity involve the action of water channels such as AQPs. In this review, we provide a comprehensive overview of the relationship between AQPs and rhinologic conditions, focusing on the current state of knowledge and mechanisms that link AQPs and rhinologic conditions. Key conclusions include the following: (1) Various AQPs are expressed in both nasal mucosa and olfactory mucosa; (2) the expression of AQPs in these tissues is different in inflammatory diseases such as AR or CRS, as compared with that in normal tissues; (3) the expression of AQPs in CRS differs depending on the presence or absence of nasal polyps; and (4) the expression of AQPs in tissues associated with olfaction is different from that in the respiratory epithelium.

Olfactory dysfunction in patients with chronic rhinosinusitis with nasal polyps is associated with clinical-cytological grading severity

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a common inflammatory disorder, affecting about 4% of the worldwide population and strongly impacting the quality of life. CRSwNP is still a challenge for ENT specialists in terms of its unknown pathogenesis, difficulty in management and frequent relapse. Olfactory impairment frequently affects CRSwNP patients. We tested the hypothesis that clinical-cytological grading (CCG) could be associated with olfactory dysfunction. The study was cross-sectional, enrolling 62 patients (37 males, 25 females, mean age 49 years, range 18-83) suffering from newly diagnosed CRSwNP. Olfactory dysfunction was very frequent (about 90%) and did not depend on nasal obstruction as assessed by both polyp size and nasal airflow limitation. A CCG > 4 was the best cut-off value to suspect olfactory dysfunction [area under the ROC curve of 0.831 (0.715 to 0.914)]; in addition, the statistical risk of having dysosmia was over 7-fold higher in subjects with CCG > 4 compared with subjects reporting a CCG < 4 (adjOR 7.46). The present study underlines that olfactory dysfunction is common in CRSwNP patients and demonstrates an association between olfactory dysfunction and inflammation, suggesting that CCG could be useful in the work-up of CRSwNP patients and in suspecting olfactory impairment.