Pathogenesis Of Chronic Rhinosinusitis With Nasal Polyps Research Articles

Epithelium-derived kallistatin promotes CD4+ T-cell chemotaxis to TH2-type inflammation in chronic rhinosinusitis

The function of kallistatin in airway inflammation, particularly chronic rhinosinusitis with nasal polyps (CRSwNP), has not been elucidated. We sought to investigate the role of kallistatin in airway inflammation. Kallistatin and proinflammatory cytokine expression levels were detected in nasal polyps. For the invivo studies, we constructed the kallistatin-overexpressing transgenic mice to elucidate the role of kallistatin in airway inflammation. Furthermore, the levels of plasma IgE and proinflammatory cytokines in the airways were evaluated in the kallistatin-/- rat invivo model under a type 2 inflammatory background. Finally, the Notch signaling pathway was explored to understand the role of kallistatin in CRSwNP. We showed that the expression of kallistatin was significantly higher in nasal polyps than in the normal nasal mucosa and correlated with IL-4 expression. We also discovered that the nasal mucosa of kallistatin-overexpressing transgenic mice expressed higher levels of IL-4 expression, associating to TH2-type inflammation. Interestingly, we observed lower IL-4 levels in the nasal mucosa and lower total plasma IgE of the kallistatin-/- group treated with house dust mite allergen compared with the wild-type house dust mite group. Finally, we observed a significant increase in the expression of Jagged2 in the nasal epithelium cells transduced with adenovirus-kallistatin. This heightened expression correlated with increased secretion of IL-4, attributed to the augmented population of CD4+CD45+Notch1+ T cells. These findings collectively may contribute to the induction of TH2-type inflammation. Kallistatin was demonstrated to be involved in the CRSwNP pathogenesis by enhancing the TH2 inflammation, which was found to be associated with more expression of IL-4, potentially facilitated through Jagged2-Notch1 signaling in CD4+ T cells.

Single-cell RNA sequencing reveals the epithelial cell, fibroblast, and key gene alterations in chronic rhinosinusitis with nasal polyps

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a chronic inflammatory disease of the nasal mucosa, and epithelial–mesenchymal transition (EMT) is thought to be an essential process in the pathogenesis of CRSwNP. However, the mechanisms of epithelial and fibroblastic changes at the single-cell level are unclear. In this study, we investigated the epithelial cell, fibroblast, and key gene alterations in the development of CRSwNP. We revealed major cell types involved in CRSwNP and nasal mucosal inflammation formation, then mapped epithelial and fibroblast subpopulations. We showed that the apical and glandular epithelial cells and the ADGRB3+ and POSTN+ fibroblasts were the key cell subtypes in the progression of CRSwNP. Pseudotime and cell cycle analysis identified dynamic changes between epithelial cells and fibroblasts during its development. WFDC2 and CCL26 were identified as the key marker genes involved in the development of CRSwNP and were validated by IHC staining, which may provide a potential novel target for future CRSwNP therapy. ScRNA-seq data provided insights into the cellular landscape and the relationship between epithelial cells and fibroblasts in the progression of CRSwNP. WFDC2 and CCL26 were identified as the key genes involved in the development of CRSwNP and may be the potential markers for gene therapy.

Expression profiles of MMP-9 and EMMPRIN in chronic rhinosinusitis with nasal polyps.

Metalloproteinases (MMPs) are implicated in tissue remodeling in chronic rhinosinusitis with nasal polyps (CRSwNP). This study aimed to evaluate the expression profiles of MMP-9 and the extracellular matrix metalloproteinase inducer (EMMPRIN) in nasal polyps compared to healthy mucosa. Tissue samples from 37 CRSwNP patients undergoing functional endoscopic sinus surgery and mucosal specimens from 12 healthy controls were obtained intra-operatively. MMP-9 and EMMPRIN mRNA levels were assessed by reverse transcription-polymerase chain reaction and their protein expression by Western blot analysis. MMP-9 mRNA expression levels were significantly elevated in CRSwNP compared to controls (p < 0.05). MMP-9 protein levels presented an increasing trend but with no statistical significance (p > 0.05). No statistically significant difference in EMMPRIN mRNA and protein levels was identified. Upregulation of MMP-9 in nasal polyps is evident and highlights its role in the pathogenesis of CRSwNP. The lack of concordance between MMP-9 mRNA and protein levels may be attributed to post-translational gene expression regulation. Although EMMPRIN expression was not significantly different between the two groups, its role remains to be elucidated. MMP-9 may be a valuable biomarker and treatment target in CRSwNP.

Comparing Protein and Gene Expression Signature between Nasal Polyps and Nasal Fluids in Chronic Rhinosinusitis

Introduction: Chronic rhinosinusitis with nasal polyps (CRSwNP) is a serious inflammatory condition. Nasal fluids (NFs) present a noninvasive alternative to nasal biopsy for studying CRSwNP pathogenesis. We aimed to compare the protein and mRNA inflammation signature between nasal polyps (NPs) and NFs. Method: The performance of polyvinyl alcohol (PVA) sponges and NFs absorbable device (NFAD) for collecting NFs from 20 patients with CRSwNP was compared using the Luminex assay. The other group consisted of four healthy controls and an additional 21 CRSwNP patients (including eosinophilic CRSwNP [ECRSwNP] and non-eosinophilic CRSwNP [NECRSwNP]) for protein quantification by Olink platform and gene expression evaluation by RNA-sequencing. Spearman’s analysis was performed to detect correlations between protein expression levels in NFs and clinical assessment variables. Results: NFAD-collected NFs contained at least a 2-fold higher concentration of cytokines than that obtained using PVA sponge, and these cytokines levels are significantly associated with NPs (ρ > 0.45, p < 0.05). Differentially expressed proteins between NFs and NPs were significantly correlated in the ECRSwNP subgroup compared with controls (ρ = 0.41, p < 0.01). Levels of Th2/IL-13, MCP4, and CCL4, characteristic of eosinophilic infiltration, were increased in ECRSwNP patients. A significant correlation between gene and protein expression was observed (ρ = 0.34, p < 0.01). PDL2 levels in NFs were positively correlated with ECRSwNP postoperative recurrence, the nasal VAS, and SNOT-22 scores (ρ > 0.68, p < 0.05 for all). Conclusion: Our study revealed similarities and discrepancies in inflammatory signatures between NPs and NFs in the same CRSwNP patient.

Overexpression of AXL on macrophages associates with disease severity and recurrence in chronic rhinosinusitis with nasal polyps.

Chronic rhinosinusitis with nasal polyps (CRSwNP) is characterized by high tissue heterogeneity and risk of postoperative recurrence, but the underlying mechanisms are poorly elucidated. This study aims to explore the expressions of AXL on macrophages and their roles in the pathogenesis of CRSwNP, and evaluate their associations with disease severity and recurrence. Healthy controls (HCs), chronic rhinosinusitis without nasal polyps (CRSsNP) and CRSwNP patients were recruited in this study. Protein and mRNA levels of AXL and macrophage markers were detected in tissue samples, and their relationships with clinical variables and risk of postoperative recurrence were assessed. Immunofluorescence staining was conducted to confirm the location of AXL and its co-expression with macrophages. Regulated AXL in THP-1 and peripheral blood mononuclear cells (PBMC)-derived macrophages, and evaluated their polarization and cytokine secretion. We found that AXL was enhanced in the mucosa and serum samples of CRSwNP patients, especially in recurrent cases. Tissue AXL levels were positively correlated with peripheral eosinophil count and percentage, Lund-Mackay score, Lund-Kennedy score, and macrophage M2 markers levels. Immunofluorescence staining results demonstrated that AXL was augmented and predominantly expressed on M2 macrophages in the tissues of CRSwNP, particularly in recurrent cases. In vitro experiment, overexpression of AXL promoted the M2 polarization of THP-1 and PBMC-derived macrophages, and facilitated the production of TGF-β1 and CCL-24. AXL driving the M2 macrophage polarization exacerbated the disease severity and contributed to the postoperative recurrence in CRSwNP patients. Our findings supported AXL-targeted prevention and treatment of recurrent CRSwNP.

Gene expression profiles of mRNA, lncRNA, miRNA, and circRNA and their clinical implications in chronic rhinosinusitis with nasal polyps.

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a chronic inflammatory disease with complex pathophysiology and therapeutic strategies. Moreover, the molecular mechanisms underlying the pathogenesis of CRSwNP are incompletely understood. This study aimed to investigate the transcriptomic characteristics, ceRNA networks, and whether these molecular markers play a role in the occurrence and development of CRSwNP. Following RNA sequencing, a ceRNA network was predicted and constructed based on the sequencing results and multiple databases. Gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and disease ontology (DO) were applied to analyze the potential mechanisms in relation to the pathogenesis of CRSwNP. CIBERSORT was used to evaluate the immune cell infiltration levels in CRSwNP. The candidate genes of differentially expressed (DE) mRNA, DE-lncRNA, DE-miRNA, and DE-circRNA were verified by RT-qPCR, and the back-splice junction of circRNA was verified using Sanger sequencing. The clinical significance of differentially expressed genes was analyzed with correlation test and receiver operating characteristic curve. We identified 716 DE-mRNA, 230 DE-lncRNA, 42 DE-miRNA, and 46 DE-circRNA, and GO and KEGG enrichment analyses indicated that they were involved in multiple biological pathways, predominantly those associated with immunity and inflammation. DO analysis revealed CRSwNP is associated with diseases such as gastroesophageal reflux and allergic reactions. High expression of circ_0021727 was significantly and positively correlated with several important clinical indicators, and the area under the curve was 0.741. This study provides transcriptomic characteristics, which are potential biomarkers or therapeutic targets for the diagnosis and treatment of CRSwNP.

Antimicrobial and Defense Proteins in Chronic Rhinosinusitis with Nasal Polyps.

Background and Objectives: Chronic rhinosinusitis with nasal polyps (CRSwNP) presently remains a difficult disease to manage. Antimicrobial and defense proteins are important factors that could help characterize the role of microorganisms in CRSwNP pathogenesis, as the concept of microbial dysbiosis in CRS is still being considered. Our aim is to investigate the complex appearance, relative distribution and interlinks of human β defensin 2 (HBD-2), human β defensin 3 (HBD-3), human β defensin 4 (HBD-4), and cathelicidin LL 37 (LL 37) in chronic rhinosinusitis with nasal polyps (CRSwNP)-affected human nasal mucosa. Materials and Methods: The study group consisted of 48 samples from patients with CRSwNP. Samples were collected during functional endoscopic sinus surgery. The control group consisted of 17 normal healthy nasal mucosa samples gathered during routine septoplasty. β-defensin-2, β-defensin-3, β-defensin-4 and cathelicidin LL 37 in tissue were detected via immunohistochemical analysis. Results: HBD-2, HBD-3 and LL 37 were significantly decreased in epithelial cells in both primary and recurrent nasal polyp samples (p < 0.001) in comparison to control samples. HBD-2 was decreased in the subepithelial connective tissue of primary nasal polyp samples when compared to both recurrent polyp (p = 0.050) and control (p = 0.033) samples. In subepithelial connective tissue, significantly more HBD-3-positive structures were observed in primary nasal polyp samples (p = 0.049) than in control samples. In primary polyp samples, moderate correlations between connective tissue HBD-3 and connective (R = 0.584, p = 0.001) and epithelial tissue LL 37 (R = 0.556, p = 0.002) were observed. Conclusions: Decreased HBD-2, HBD-3 and LL 37 concentrations in the epithelium suggest a dysfunction of the epithelial barrier in patients with nasal polyps. Decreased subepithelial connective tissue HBD-2 suggests different responses to nasal microbiota in patients with primary nasal polyps compared to recurrent nasal polyps. Increased HBD-3 in subepithelial connective tissue suggests a possible role of this antimicrobial peptide in the pathogenesis of primary nasal polyps.

Blood Basophils Relevance in Chronic Rhinosinusitis with Aspirin-Exacerbated Respiratory Disease.

Aspirin-exacerbated respiratory disease (AERD) is characterized by eosinophilic asthma, chronic rhinosinusitis with nasal polyps (CRSwNP) and intolerance to cyclooxygenase-1 inhibitors. Interest is emerging in studying the role of circulating inflammatory cells in CRSwNP pathogenesis and its course, as well as their potential use for a patient-tailored approach. By releasing IL-4, basophils play a crucial role in activating the Th2-mediated response. The main aim of this study was to, first, investigate the level of the pre-operative blood basophils' values, blood basophil/lymphocyte ratio (bBLR) and blood eosinophil-to-basophil ratio (bEBR) as predictors of recurrent polyps after endoscopic sinus surgery (ESS) in AERD patients. The secondary aim was to compare the blood basophil-related variables of the AERD series (study group) with those of a control group of 95 consecutive cases of histologically non-eosinophilic CRSwNP. The AERD group showed a higher recurrence rate than the control group (p < 0.0001). The pre-operative blood basophil count and pre-operative bEBR were higher in AERD patients than in the control group (p = 0.0364 and p = 0.0006, respectively). The results of this study support the hypothesis that polyps removal may contribute to reducing the inflammation and activation of basophils.

TNFRSF13B/TACI Mutations in Patients with Chronic Rhinosinusitis with Nasal Polyps.

The pathogenesis of Chronic Rhinosinusitis with Nasal Polyps (CRSwNP) remains still inconclusive. Recent studies identified an increased expression of BAFF (a B cell-activating factor) and its receptor TACI (Transmembrane Activator and cAML Interactor) in nasal polyp samples, while TNFRSF13B/TACI mutations have been found in patients with benign lymphoproliferative disorders and primary antibody deficiencies. The aim of our study was to evaluate the possible contribution of TNFRSF13B/TACI mutations in CRSwNP pathogenesis. Forty-four (44) patients with CRSwNP (male/female: 33/11, mean age: 52.5 years, range: 16-83) were analyzed for TNFRSF13B/TACI mutations by PCR-sequencing. No pathogenic TNFRSF13B/TACI mutations were identified in our cohort study of CRSwNP patients. We detected two common missense mutations (p.P251L and p.V220A), along with other common silent mutations and intronic polymorphisms in an identical prevalence to healthy control population. TNFRSF13B/TACI mutations might not play a role in the pathogenesis of CRSwNP.

Delineation of T cell subsets in chronic rhinosinusitis with nasal polyps.

Detailed characterisation of CD45RA+ and CD45RO+ T cell subsets in both CD4+ and CD8+ cells in blood and tissue of patients with chronic rhinosinusitis with nasal polyps (CRSwNP) is lacking. We aimed to investigate T cell differentiation levels in blood and tissue and correlate this with CT score and white blood cell count. This case-control study was conducted on 21 patients with CRSwNP and 20 healthy controls. Lund-Mackay score was used for radiologic staging of chronic rhinosinusitis. T cell subsets were characterised in blood and nasal polyp tissue using CD4, CD8, CCR7, CD45RA, CD45RO, CD27, and CD95 monoclonal antibodies. Most variations in T cell subsets were detected in tissue rather than blood. A higher level of CD8+ TCM, CD4+ TSCMs and lower level of CD8+ TEM were detected in the blood of CRSwNP patients vs controls. In CRSwNP patients, substantial decrease of tissue CD8+ TNs, CD8+ TCMs, CD4+ TNs, and CD4+TSCMs with marked increase in the percentages of TEMs and TEMRAs were detected among CD4+ and CD8+ T cells compared with levels in blood. The reduction of TNs, TSCMs, and TCMs and accumulation of TEMs and TEMRAs subsets that function as effector cells in sinonasal mucosa, especially CD8+ T cells, might indicate the role of immunomodulation of memory/effector T-cells in the pathogenesis of CRSwNP.

Identification of hub genes and immune cell infiltration characteristics in chronic rhinosinusitis with nasal polyps: Bioinformatics analysis and experimental validation.

The aim of our study is to reveal the hub genes related to the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP) and their association with immune cell infiltration through bioinformatics analysis combined with experimental validation. In this study, through differential gene expression analysis, 1,516 upregulated and 1,307 downregulated DEG were obtained from dataset GSE136825 of the GEO database. We identified 14 co-expressed modules using weighted gene co-expression network analysis (WGCNA), among which the most significant positive and negative correlations were MEgreen and MEturquoise modules, containing 1,540 and 3,710 genes respectively. After the intersection of the two modules and DEG, two gene sets—DEG-MEgreen and DEG-MEturquoise—were obtained, containing 395 and 1,168 genes respectively. Through GO term analysis, it was found that immune response and signal transduction are the most important biological processes. We found, based on KEGG pathway enrichment analysis, that osteoclast differentiations, cytokine–cytokine receptor interactions, and neuroactive ligand–receptor interactions are the most important in the two gene sets. Through PPI network analysis, we listed the top-ten genes for the concentrated connectivity of the two gene sets. Next, a few genes were verified by qPCR experiments, and FPR2, ITGAM, C3AR1, FCER1G, CYBB in DEG-MEgreen and GNG4, NMUR2, and GNG7 in DEG-MEturquoise were confirmed to be related to the pathogenesis of CRSwNP. NP immune cell infiltration analysis revealed a significant difference in the proportion of immune cells between the NP group and control group. Finally, correlation analysis between target hub genes and immune cells indicated that FPR2 and GNG7 had a positive or negative correlation with some specific immune cells. In summary, the discoveries of these new hub genes and their association with immune cell infiltration are of great significance for uncovering the specific pathogenesis of CRSwNP and searching for disease biomarkers and potential therapeutic targets.

Transcriptome sequencing reveals altered ciliogenesis under hypoxia in nasal epithelial cells from chronic rhinosinusitis with nasal polyps.

BackgroundHypoxia is considered a key factor in the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP). However, the specific mechanism driving polypogenesis under hypoxic conditions is unclear. This study aimed to explore hypoxia‐induced alterations in the transcriptome of human nasal epithelial cells (HNECs) in vitro.MethodsHNECs derived from the tissue of patients with CRSwNP were established as air–liquid interface (ALI) cultures. Confluent cultures were kept submerged or treated with cobalt chloride (CoCl2) to induce hypoxia. Transcriptome analysis was used to identify key mRNAs involved in this process. Real‐time PCR (RT–PCR), Western blotting, and immunofluorescence were used to observe the effects of hypoxia on ciliogenesis.ResultsNumerous genes, biological processes and pathways were altered under submerged culture conditions or after CoCl2 treatment. Analysis of the results under both hypoxic conditions revealed that the transcriptional program responsible for ciliogenesis was significantly impaired. Downregulation of cilia‐related genes and inhibition of ciliated cell differentiation under hypoxia were confirmed by RT–PCR, Western blot and immunofluorescence analyses.ConclusionHypoxia impairs ciliogenesis and ciliary function in HNECs, which might play a role in the pathogenesis of CRSwNP.

Identification of lncRNA Biomarkers and LINC01198 Promotes Progression of Chronic Rhinosinusitis with Nasal Polyps through Sponge miR-6776-5p.

Background Chronic sinusitis (CRS) was a chronic inflammation that originated in the nasal mucosa and affected the health of most people around the world. Chronic rhinosinusitis with nasal polyps (CRSwNP) was one kind of chronic sinusitis. Emerging research had suggested that long noncoding RNAs (lncRNAs) played vital parts in inflammatories and inflammation development. Methods We acquired GEO data to analyze the differential expression between the miRNA, immune genes, TF, and lncRNA data in CRSWNP and the corresponding control tissues. Bioinformatic analysis by coexpression of endogenous RNA network and competitive way enrichment, analysis, and forecasting functions of these noncoding RNA. The different pathway expressions in CRSwNP patients were confirmed using GSVA to analyze the differentially expressed immune genes and TF data sets in CRSwNP patients. The differential immune gene and transcription factor data set in CRSwNP perform functional notes and protein-protein interaction (PPI) network structure. We predicted the potential genes and RNAs related to CRSWNP by constructing a ceRNA network. In addition, we also used 19 hub immune genes to predict the potential drugs of CRSWNP. lncRNA biomarkers in CRSwNP were identified by lncRNAs LASSO regression. The CIBERSORT algorithm was used to contrast the divergence in immune infiltrations between CRSwNP and usual inferior turbinate organizations in 22 immunocyte subgroups. Results We identified a total of 48 miRNAs, 304 lncRNAs, 92 TFs, and 525 immune genes as CRSwNP-specific RNAs. GO and KEGG pathways both analyzed differentially expressed immune genes and transcription factor data sets. We predicted the potential genes GNG7, TUSC8, LINC01198, and has-miR-6776-5p by constructing ceRNA and PPI networks. At the same time, we found that the above genes were involved in two important pathways: chemokine signal path and PI3K/AKT signal path. In addition, we predicted 5 small molecule drugs to treat CRSwNP by analyzing 19 central immune genes, namely, danazol, ikarugamycin, semustine, cefamandole, and molindone. Finally, we identified 5 biomarkers in CRSwNP, namely, LINC01198, LINC01094, LINC01798, LINC01829, and LINC01320. Conclusions We had identified CRSwNP-related miRNAs, lncRNAs, TFs, and immune genes, which may be making use of latent therapeutic target for CRSwNP. At the same time, we identified 5 lncRNA biomarkers in CRSwNP. The results of this study showed that LINC01198 promoted the progression of CRSwNPs through spongy miR-6776-5p. Our studies provide a new way for further analyses of the pathogenesis of CRSwNP.

The role of raftlin in the pathogenesis of chronic rhinosinusitis with nasal polyps.

The aim of this study was to investigate the possible role of raftlin (RFTN) in chronic rhinosinusitis with nasal polyps (CRSwNP). There is no study in the literature investigating the role of RFTN in the pathogenesis of CRSwNP. The present study was designed as a case-control study and conducted between 25.09.2020 and 01.01.2022. CRSwNP and control groups were formed in the study. Serum and tissue samples were taken from each patient in the study and their RFTN levels were measured. While nasal polyps were used for tissue samples in the CRSwNP group, middle meatus mucosa obtained during concha bullosa surgery was used in the control group. The control group included 31 patients (8 female, 23 male) and the CRSwNP group included 49 patients (14 female, 35 male). The mean age of the control group was 40.42 ± 9.99years, while the mean age of the CRSwNP group was 43.47 ± 10.19years. When the groups are compared in terms of gender and age, there were no statistically significant differences (p = 0.78, p = 0.19, respectively). The serum RFTN levels in the control and CRSwNP groups were 7.85 ± 10.87ng/ml, and 7.02 ± 8.59ng/ml, respectively (p = 0.45). The tissue RFTN levels in the control group and CRSwNP group were 87.15 ± 69.91ng/ml, and 66.50 ± 17.10ng/ml, respectively (p = 0.04, statistically significant). RFTN deficiency in nasal polyp tissue may be one of the reasons for the development of CRSwNP. Further studies are needed to elucidate the role of RFTN in CRSwNP.

The roles of eosinophils and interleukin-5 in the pathophysiology of chronic rhinosinusitis with nasal polyps.

Chronic rhinosinusitis with nasal polyps (CRSwNP) is generally associated with eosinophilic tissue infiltration linked to type 2 inflammation and characterized by elevated levels of interleukin (IL)-5 and other type 2 inflammatory mediators. Although distinct and overlapping contributions of eosinophils and IL-5 to CRSwNP pathology are still being explored, they are both known to play an important role in NP inflammation. Eosinophils secrete numerous type 2 inflammatory mediators including granule proteins, enzymes, cytokines, chemokines, growth factors, lipids, and oxidative products. IL-5 is critical for the differentiation, migration, activation, and survival of eosinophils but is also implicated in the biological functions of mast cells, basophils, innate lymphoid cells, B cells, and epithelial cells. Results from clinical trials of therapeutics that target type 2 inflammatory mediators (including but not limited to anti-IL-5, anti-immunoglobulin-E, and anti-IL-4/13) may provide further evidence of how eosinophils and IL-5 contribute to CRSwNP. Finally, the association between eosinophilia/elevated IL-5 and greater rates of NP recurrence after endoscopic sinus surgery (ESS) suggests that these mediators may have utility as biomarkers of NP recurrence in diagnosing and assessing the severity of CRSwNP. This review provides an overview of eosinophil and IL-5 biology and explores the literature regarding the role of these mediators in CRSwNP pathogenesis and NP recurrence following ESS. Based on current published evidence, we suggest that although eosinophils play a key role in CRSwNP pathophysiology, IL-5, a cytokine that activates these cells, also represents a pertinent and effective treatment target in patients with CRSwNP.

Role and Function of Regulatory T Cell in Chronic Rhinosinusitis with Nasal Polyposis

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a subtype of chronic rhinosinusitis characterized by high edema in the stroma, albumin deposition, and formation of pseudocysts. The pathogenesis of CRSwNP is not yet fully understood. Regulatory T (Treg) cells are a subset of CD4+ T cells that play a suppressive immunoregulatory role in the process of CRSwNP. Recent studies have found that there was a significant reduction in Treg cells in polyp tissues, which leads to the onset of CRSwNP. An imbalance between Th17 and Treg cells can also aggravate inflammation toward the Th2 type. This review focuses on our understanding of the function and role of Treg cells and their regulatory factors and clinical significance in CRSwNP. We also summarize the current drug treatments for CRSwNP with Tregs as the potential therapeutic target, which will provide new ideas for the treatment of CRSwNP in the future.

EGF Protects Epithelial Cells from Barrier Damage in Chronic Rhinosinusitis with Nasal Polyps.

BackgroundThe aim of this study is to investigate the potential key genes related to Chronic rhinosinusitis with nasal polyps (CRSwNP).MethodsDatasets GSE36830 and GSE72713 were obtained from Gene Expression Omnibus. Dataset GSE36830 was used to identify differentially expressed genes in CRSwNP patients. GO, KEGG analysis, and PPI network analysis were applied to further investigate the function of DEGs in CRSwNP. GSEA was also performed to explore the mechanisms of DEGs. Dataset GSE72713 was applied to validate the key gene. Moreover, to detect the expression of target gene, nasal polyp tissues and middle turbinate specimens were collected from CRSwNP patients (n = 20) and controls (n = 20), respectively. RT-PCR, Western blot, and immunofluorescence staining were applied. HE and AB-PAS staining were used to assess the infiltration of inflammatory cells. The proliferation and migration ability of human nasal epithelial cells (HNEpCs) were tested via Cell Counting kit-8, wound healing assay and Transwell migration assay. Air–liquid interface was used to culture primary human nasal epithelial cells (pHNECs) from health controls and nasal polyp tissues of CRSwNP patients.ResultsA total of 1035 DEGs were identified, and 661 genes were up-regulated and 374 genes were down-regulated. According to PPI network analysis, the top 10 scored genes were identified. Among them, only EGF was down-regulated in CRSwNP. Meanwhile, GSEA result shows that EGF is significantly enriched in WNT activated receptor activity. CCK-8, wound healing assay, and transwell migration assay indicated that recombinant human EGF can promote the proliferation and migration of HNEpCs in vitro. Immunofluorescence staining shows that rhEGF can increase the expression of ZO-1 in pHNECs from nasal polyp tissues.ConclusionBioinformatics analysis and in vitro experiments were used to explore the pathogenesis of CRSwNP, and the results showed that EGF may play an important role in the protection of nasal epithelial barrier.

Elevation of activated neutrophils in chronic rhinosinusitis with nasal polyps

Chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP) is well characterized by type 2 (T2) inflammation characterized by eosinophilia in Western countries. However, the presence and roles of neutrophils in T2 CRSwNP are poorly understood. We sought to clarify accumulation and inflammatory roles of neutrophils in CRSwNP in a Western population. Sinonasal tissues and nasal lavage fluids were obtained from control patients and patients with CRS, and neutrophil markers were determined by ELISA. The presence of neutrophils in tissue was determined by flow cytometry. The gene expression profiles in neutrophils were determined by RNA sequencing. A neutrophil marker elastase was selectively elevated in nasal polyp (NP) tissue, whereas eosinophilic cationic protein (an eosinophil marker) was elevated in both uncinate and NP tissues of CRSwNP patients. Nasal lavage fluid myeloperoxidase (another neutrophil marker) was also significantly elevated in CRSwNP compared to control patients. Neutrophil markers were more greatly elevated in CRSwNP patients with recurrent disease. Flow cytometric analysis confirmed that neutrophil numbers were significantly elevated in NPs compared to control tissues. RNA sequencing analysis found that 344 genes were >3-fold and significantly elevated in NP neutrophils compared to peripheral blood neutrophils. Gene Ontology analysis suggested that the elevated genes in NP neutrophils were significantly associated with activation. Results suggest that neutrophils are accumulated in T2 NP tissues and that accumulated neutrophils are highly activated and contribute to inflammation in NPs. Neutrophils may play a heretofore unrecognized meaningful role in the pathogenesis of CRSwNP in Western countries and may be a potentially important therapeutic target in T2 CRSwNP.

Air Pollution Exposure Affects Severity and Cellular Endotype of Chronic Rhinosinusitis With Nasal Polyps.

Air pollution has emerged as an important environmental risk factor for chronic rhinosinusitis (CRS) progression. This study assessed exposure to five types of air pollution (PM2.5/10 , SO2 , NO2 , CO, O3 ) and explored their effects on CRS with nasal polyps (CRSwNP) severity and endotype. Retrospective cohort study. Air pollution data from monitoring sites in Beijing were obtained to assess individual air pollution exposure. Outcomes of CRSwNP (n=282) including Lund-Mackay (L-M) score, Lund-Kennedy (L-K) score, visual analogue scale (VAS) score and nasal patency/airflow resistance and so on were measured to analyze correlations with air pollution and compare groups with different exposure types. Multivariable-adjusted binary logistic regression was used to determine potential air pollution risk factors of the endotype of eosinophilic CRSwNP (ECRSwNP). Short-term exposures to PM2.5/10 , SO2 , CO, NO2 , and O3 were weak but significantly associated with increased L-M scores. Short-term exposures to PM10 , CO, and NO2 were correlated with increased VAS headache/facial pain scores. The L-M scores of the group of the highest PM2.5 (≥150 μg/m3 ) exposure were significantly higher than those of control group. For each increased unit of the average concentration of PM2.5 , there was a 1.047-fold (95% confidence interval, 1.005-1.091) increased risk of the endotype of ECRSwNP. Air pollution exposure exacerbated CRSwNP severity and PM2.5 could be a risk factor for endotype of ECRSwNP, suggesting the role of air pollution in CRSwNP pathogenesis. 4 Laryngoscope, 132:2103-2110, 2022.

Necroptosis Underlies Neutrophilic Inflammation Associated with the Chronic Rhinosinusitis with Nasal Polyps (CRSwNP).

BackgroundNecroptosis is an inflammatory cell death associated with a variety of chronic diseases. Chronic rhinosinusitis with nasal polyps (CRSwNP) is a chronic inflammatory disease accompanied by eosinophil and neutrophil infiltration. The role of necroptosis in the pathogenesis of CRSwNP remains elusive.MethodsCell death, including apoptosis, pyroptosis and necroptosis in control sinonasal mucosa and CRSwNP, were analyzed by immunoblotting, immunohistochemistry (IHC) and immunofluorescence (IF) staining for cleaved caspase 3, cleaved gasdermin D and p-MLKL, respectively. Correlations between necroptosis, inflammatory cytokines and neutrophil infiltration were assessed and a possible role of necroptosis in CRSwNP was evaluated. Primary nasal polyp cells (DNPCs) were stimulated with damage-associated molecular patterns (DAMPs) including ATP or IL-1α and their expression of inflammatory cytokines was analyzed using RT-PCR. The expression of TNF-α and IFNs in nasal polyps was measured by ELISA; human monocyte THP-1 cells were treated with TNF-α or IFN-γ and cell death was measured by LDH release.ResultsNecroptosis, rather than apoptosis or pyroptosis, was overtly activated in both eosinophilic and non-eosinophilic CRSwNP as evidenced by the presence of prominent phosphorylation of MLKL compared to controls. The abundance of DAMPs (IL-1α, HMGB1), inflammatory cytokines (IL-6) and chemokines (IL-8, CXCL-1) were all increased especially in non-eosinophilic CRSwNP. The extent of necroptosis was positively correlated with the abundance of DAMPs and cytokines, and neutrophil infiltration in CRSwNP. In DNPCs, ATP and IL-1α induced the expression of IL-8 and CXCL-1. Macrophage was found to be the predominant cell type positive for p-MLKL in CRSwNP. Concomitant treatment with TNF-α and IFN-γ, which were abundantly present in CRSwNP, triggered marked necroptosis in THP-1 cells.ConclusionNecroptosis induced by TNF-α and IFN-γ may facilitate the production and release of a myriad of proinflammatory cytokines and entailed neutrophil infiltration to exacerbate inflammation in CRSwNP.