Eosinophilic Nasal Polyps Research Articles

The role of CD24hiCD27+ regulatory B cells in human chronic rhinosinusitis with/without nasal polyps

BackgroundRegulatory B cells (Bregs) reduce allergic and autoimmune inflammation. However, their role in chronic rhinosinusitis (CRS) remains unknown. This study investigated the frequency and function of Breg subsets in the peripheral blood of patients with CRS. MethodsThe demographic and clinical characteristics were compared among control, CRSsNP, neCRSwNP, and eCRSwNP groups. The expression of various Breg subtypes was evaluated in peripheral blood mononuclear cells (PBMCs) of patients with eosinophilic CRS with nasal polyps (eCRSwNP), non-eosinophilic CRS with nasal polyps (neCRSwNP), CRS without nasal polyps (CRSsNP). CD19+CD24hiCD27+ B cells (B10 cells) were isolated by flow cytometry, followed by RNA sequencing (RNA-seq). Finally, IL-10 secreted by B10 cells were evaluated through the intracellular stain. ResultsA higher number of eosinophils in peripheral blood and nasal polyps were found in eCRSwNP compared with neCRSwNP, CRSsNP, and control groups. The frequency of B10 in the peripheral blood B cells (B10%) of patients with eCRSwNP was significantly lower than that in the neCRSwNP and control groups. B10% was negatively correlated with the quantity of tissue eosinophils, and the percentage and absolute value of peripheral blood eosinophils. The eCRSwNP, neCRSwNP and control groups had 1403 differentially expressed genes, 35 of which were identified in four highly enriched pathways. Additionally, the frequency of IL-10+B10 cells in peripheral blood was lower in patients with eCRSwNP than in the neCRSwNP and control groups. ConclusionThis study is the first to reveal differences in both the quantity and IL-10 secretion of B10 cells in patients with eCRSwNP and neCRSwNP. These variations were strongly negatively associated with eosinophils in nasal polyps and peripheral blood. IL-10+B10 cells may play a key role in the pathological mechanisms of CRS, particularly the recurrence of eCRSwNP.

Unsupervised clustering analysis based on multidimensional features reveals distinct clinical characteristics and associated factors of different phenotypes in patients with chronic rhinosinusitis with nasal polyp

Objective: To utilize routinely available clinical parameters to uncover the clinical features of different clusters in patients with chronic rhinosinusitis with nasal polyp (CRSwNP) through unsupervised clustering analysis. Methods: The clinical data from 155 CRSwNP patients undergoing nasal endoscopic surgery at Renmin Hospital of Wuhan University from 2021 to 2023 were prospectively collected, including 112 males and 43 females, aged from 7 to 87 years. Unsupervised clustering analysis was conducted using various clinical parameters, including age, gender, smoking and drinking history, local eosinophil (EOS) and neutrophil (NEU) counts, comorbid allergic rhinitis (AR), comorbid asthma, recurrence status, serum-specific IgE, total IgE, cytokine levels, peripheral blood EOS count and percentage, Lund-Mackay CT score, the ratio of CT scores for the maxillary sinus and ethmoid sinus (E/M ratio), visual analogue scale (VAS) score, Lund-Kennedy endoscopic score, and other common clinical indicators to elucidate the clinical characteristics of each cluster. Statistical analysis was conducted using GraphPad Prism 9.5 software. Results: Hierarchical clustering analysis identified four main clusters (Cluster A1-A4), showcasing distinct characteristics such as mild nasal polyps with higher peripheral blood cytokines levels, nasal polyps accompanied by allergies and asthma, a subtype of nasal polyps with high recurrence rates dominated by neutrophils, and nasal polyps with high eosinophil levels. Further subset clustering revealed two clusters of mild polyps (Cluster B1-B2) featuring high cytokine expression and comorbid AR; and two clusters of severe polyps (Cluster B3-B4) presented with severe symptoms, high Lund-Mackay CT score, and high Lund-Kennedy endoscopic score. Variations between Cluster B3 and B4 included symptom complexity, the degree of eosinophil infiltration, and the probability of comorbid asthma. Further clustering analysis for eosinophilic nasal polyps revealed a cluster characterized by highly neutrophilic infiltration and recurrent nasal polyps. The comprehensive analysis of multi-index correlations demonstrated valuable insights into the relationships between common clinical parameters of nasal polyps, providing valuable information for a deeper understanding of the pathogenesis of CRSwNP. Conclusion: The clustering analysis in this study categorizes CRSwNP patients into different clusters based on clinical features and disease outcomes, providing a new perspective for more precise clinical treatment strategies.

Single cell RNA sequencing of human eosinophils from nasal polyps reveals eosinophil heterogeneity in chronic rhinosinusitis tissue

BackgroundChronic rhinosinusitis with nasal polyps (CRSwNP) is characterized by type 2 inflammation in the US, yet the actual roles of eosinophils in CRSwNP are largely unclear. ObjectiveTo reveal the roles and heterogeneity of eosinophils in nasal polyp (NP) tissue by single cell RNA-Sequencing (scRNA-Seq) analysis of NP tissue. MethodsSinonasal tissues (NP and control sinus tissue) and patient matched peripheral blood (PB) samples were obtained from 5 control patients and 5 patients with CRSwNP. Eosinophils were enriched prior to processing for scRNA-Seq. The gene expression profiles in eosinophils were determined by the microwell-based scRNA-Seq technology (BD Rhapsody platform). We predicted the overall function of NP eosinophils by gene ontology (GO) enrichment and pathway analyses and confirmed expression of selected genes by flow cytometry. ResultsAfter filtering out contaminating cells, we detected 5,542 eosinophils from control PB, 3,883 eosinophils from CRSwNP PB, 101 eosinophils from control sinus tissues (not included in further analyses) and 9,727 eosinophils from NPs by scRNA-Seq. We found that 204 genes were down-regulated, and 354 genes were up-regulated in NP eosinophils, compared to all PB eosinophils (>1.5-fold, Padj<0.05). Up-regulated genes in NP eosinophils were associated with activation, cytokine-mediated signaling, growth factor activity, NF-κB signaling and anti-apoptotic molecules. NP eosinophils displayed 4 clusters revealing potential heterogeneity of eosinophils in NP tissue. ConclusionsElevated eosinophils in NP tissue appear to exist in several subtypes that may play important pathogenic roles in CRSwNP, in part via controlling inflammation and hyperproliferation of other cells.

The value of combined detection of specific immunoglobulin E, interleukin-6 and regulatory T cells in predicting the risk of postoperative recurrence in patients with eosinophilic chronic rhinosinusitis and nasal polyps.

To investigate the predictive value of specific immunoglobulin E (sIgE), interleukin-6 (IL-6) and regulatory T cells (Treg) on the risk of postoperative recurrence in patients with eosinophilic Chronic rhinosinusitis with nasal polyps (EcRswNP). A total of 198 patients with EcRswNP collected to our Hospital from January 2019 to December 2021 were selected as the research subjects. All patients underwent functional endoscopic sinus surgery. The patients were selected to recurrence group (RG, n = 48) and nonrecurrence group (NRG, n = 150) on the basis of the recurrence after 1 year of follow-up. The related factors of postoperative recurrence of EcRswNP were analyzed. The ROC was used to analyze the dangerous of sIgE, IL-6 and Treg in predicting postoperative recurrence of EcRswNP patients. The proportion of asthma patients, nasal congestion VAS score, and peripheral blood Eos% content in the RG exceeded that in the NRG, and the Organization Neu % and peripheral blood Neu% levels were less than those in the NRGp (P all < 0.05). The serum sIgE and serum IL6 in the RG were higher than those in the NRG, while the level of peripheral blood Treg was lower than that in the NRG (P < 0.05). Logistic regression analysis showed that high levels of serum sIgE, serum IL-6 and low Treg levels were risk factors for postoperative recurrence (P < 0.05). ROC showed that the AUC of peripheral blood sIgE level, IL-6 and Treg levels alone in predicting the dangerous of postoperative recurrence in patients with EcRswNP were 0.786, 0.707 and 0.636, respectively (all P < 0.05); The AUC of combined prediction of peripheral blood sIgE, IL-6 and Treg levels for postoperative recurrence dangerous in patients with EcRswNP was 0.973, indicating that the efficacy of jointed prediction was exceed than that of single prediction (P < 0.05). The high levels of sIgE, IL6 and low Treg levels in patients with EcRswNP before operation will increase the risk of postoperative recurrence, which is a risk factor affecting postoperative recurrence, and the three indicators have good predictive value for predicting postoperative recurrence in patients with EcRswNP, and the combination of the three indicators has better value in predicting postoperative recurrence.

Increased SERPINB2 potentiates 15LO1 expression via STAT6 signalling in epithelial cells in eosinophilic chronic rhinosinusitis with nasal polyps.

SERPINB2, a biomarker of Type-2 (T2) inflammatory processes, has been described in the context of asthma. Chronic rhinosinusitis with nasal polyps (CRSwNP) is also correlated with T2 inflammation and elevated 15LO1 induced by IL-4/13 in nasal epithelial cells. The aim of this study was to evaluate the expression and location of SERPINB2 in nasal epithelial cells (NECs) and determine whether SERPINB2 regulates 15LO1 and downstream T2 markers in NECs via STAT6 signalling. SERPINB2 gene expression in bulk and single-cell RNAseq database was analysed by bioinformatics analysis. SERPINB2, 15LO1 and other T2 markers were evaluated from CRSwNP and HCs NECs. The colocalization of SERPINB2 and 15LO1 was evaluated by immunofluorescence. Fresh NECs were cultured at an air-liquid interface with or without IL-13, SERPINB2 Dicer-substrate short interfering RNAs (DsiRNAs) transfection, exogenous SERPINB2, 15-HETE recombinant protein and pSTAT6 inhibitors. 15LO1, 15-HETE and downstream T2 markers were analysed by qRT-PCR, western blot and ELISA. SERPINB2 expression was increased in eosinophilic nasal polyps compared with that in noneosinophilic nasal polyps and control tissues and positively correlated with 15LO1 and other downstream T2 markers. SERPINB2 was predominantly expressed by epithelial cells in NP tissue and was colocalized with 15LO1. In primary NECs invitro, SERPINB2 expression was induced by IL-13. Knockdown or overexpression SERPINB2 decreased or enhanced expression of 15LO1 and 15-HETE in NECs, respectively, in a STAT6-dependent manner. SERPINB2 siRNA also inhibited the expression of the 15LO1 downstream genes, such as CCL26, POSTN and NOS2. STAT6 inhibition similarly decreased SERPINB2-induced 15LO1. SERPINB2 is increased in NP epithelial cells of eosinophilic CRSwNP (eCRSwNP) and contributes to T2 inflammation via STAT6 signalling. SERPINB2 could be considered a novel therapeutic target for eCRSwNP.

Up-regulation of systemic and local BDNF in non-allergic Nasal Polyps in China.

Although the role of brain-derived neurotrophic factor (BDNF) in allergic rhinitis and/or nasal polyps (NPs) development has been studied, the contribution of BDNF in non-allergic NPs has not been evaluated yet. This study was to investigate the possible role of BDNF in non-allergic NPs pathogenesis. The study was carried out at The Second Hospital of Shandong University from December 2020 to November 2021. The non-allergic NPs patients (n=26) and the control group (n=22) were included. Lund-Mackay CT scores, nasal endoscopy scores, and pulmonary function testing were evaluated before surgery. Tissue and serum levels of BDNF, eosinophil cationic protein (ECP), and cytokeratins 5 (CK5) were assessed between different groups. The BDNF level in serum and tissue, CK5 count, and eosinophil infiltration in tissue were higher in non-allergic NPs. The eosinophils infiltration, ECP mRNA expression level, as well as BDNF mRNA level were increased in the BDNFhigh subgroup compared with BDNFlow subgroup. Significantly negative correlations between BDNF count and the situation of airway obstruction were found in non-allergic NPs. BDNF may have both local and systemic effects in non-allergic NPs pathogenesis. BDNF may be a possible therapeutic target or an indicator for eosinophilic NPs management.

RECENT ACHIEVEMENTS IN THE STUDY OF PATHOMECHANISMS OF RHYNOSINUSITIS ASSOCIATED WITH NON-STEROID ANTI-INFLAMMATORS INTOLERANCE (literature review)

Background. The pathomechanism of rhinosinusitis associated with the use of non-steroidal anti-inflammatory drugs is complex and still not fully understood. They are now known to be associated with genetic predisposition and environmental triggers that lead to dysregulation of fatty acid and lipid metabolism, cell transmetabolism, and chronic inflammation in the airways.&#x0D; Aim: analysis of recent advances in the study of aspirin-associated respiratory disease (AERD), summarization of already known information about the pathomechanisms of the disease.&#x0D; Materials and methods. The analysis of literary sources included publications in the international electronic scientometric databases PubMed, Scopus, Web of Science by keywords for the period 2013-2023. 46 sources were selected for analysis, of which 24 were used that met the search criteria.&#x0D; Results. The results showed that researchers are actively studying the role of immunological factors, particularly IgG4 and IgE in the pathogenesis of the disease. IgG4 was detected in nasal polyp tissue and associated with poor postoperative outcome, which may indicate its important role in chronic sinusitis. In addition, cytokines such as thymic stromal lymphopoietin, IL-4, IL-10, IL-5, IL-13, and IL-33 have been detected in eosinophilic nasal polyps in patients with aspirin intolerance, suggesting their possible role in the development AERD.&#x0D; Conclusion. The cause of severe nasal polyposis in AERD has not been definitively determined. Further research may lead to the development of more personalized treatments. Dietary modification and development of new monoclonal antibody drugs lead to reduction of AERD symptoms and improvement of patients' quality of life.

E3 ubiquitin ligase NEDD4L inhibits epithelial-mesenchymal transition by suppressing the β-catenin/HIF-1α positive feedback loop in chronic rhinosinusitis with nasal polyps.

Chronic rhinosinusitis with nasal polyp (CRSwNP) is a refractory inflammatory disease with epithelial-mesenchymal transition (EMT) as one of the key features. Since ubiquitin modification has been shown to regulate the EMT process in other diseases, targeting ubiquitin ligases may be a potential strategy for the treatment of CRSwNP. In this study we investigated whether certain E3 ubiquitin ligases could regulate the EMT process in CRSwNP, and whether these regulations could be the potential drug targets as well as the underlying mechanisms. After screening the potential drug target by bioinformatic analyses, the expression levels of three potential E3 ubiquitin ligases were compared among the control, eosinophilic nasal polyp (ENP) and non-eosinophilic nasal polyp (NENP) group in clinical samples, and the significant decrement of the expression level of NEDD4L was found. Then, IP-MS, bioinformatics and immunohistochemistry studies suggested that low NEDD4L expression may be associated with the EMT process. In human nasal epithelial cells (hNECs) and human nasal epithelial cell line RPMI 2650, knockdown of NEDD4L promoted EMT, while upregulating NEDD4L reversed this effect, suggesting that NEDD4L inhibited EMT in nasal epithelial cells. IP-MS and Co-IP studies revealed that NEDD4L mediated the degradation of DDR1. We demonstrated that NEDD4Linhibitedthe β-catenin/HIF-1α positive feedback loop either directly(degrading β-catenin and HIF-1α) or indirectly (mediatingDDR1 degradation).These results were confirmed in a murine NP model in vivo. This study for the first time reveals the regulatory role of ubiquitin in the EMT process of nasal epithelial cells, and identifies a novel drug target NEDD4L, which has promising efficacy against both ENP and NENP by suppressing β-catenin/HIF-1α positive feedback loop.

Differential expression of NEDD8 in different pathological types of chronic rhinosinusitis with nasal polyps

Objective:To analyze the differential expression of neural precursor cell-expressed developmentally downregulated 8（NEDD8） protein in nasal polyp tissues of patients with different pathological types of chronic rhinorhinosinusitis with nasal polyps（CRSwNP）. Methods:All specimens were obtained from the specimen library of Beijing Tongren Hospital, and were all patients who underwent nasal endoscopic surgery for chronic rhinosinusitis in Beijing Tongren Hospital. Hematoxylin-eosin staining（HE） was used to detect the number of eosinophils in nasal polyps, and CRSwNP patients were grouped according to the number of eosinophils in nasal polyps, immunohistochemistry was used to detect and analyze the expression level of NEDD8 protein in nasal polyps. Results:The expression level of NEDD8 protein in nasal polyps of patients with eosinophilic chronic rhinorhinosinusitis with nasal polyps was significantly higher than that of patients with non-eosinophilic chronic rhinosinusitis and nasal polyps（P<0.05）. In addition, there was a significant positive correlation between the expression level of NEDD8 protein and the number of eosinophils in nasal polyp tissue（r=0.79, P=0.02）. Conclusion:There are differences in the expression of NEDD8 protein in patients with chronic rhinosinusitis and nasal polyps of different pathological types.

Inhibition of IL-4/STAT6/IRF4 signaling reduces the epithelial-mesenchymal transition in eosinophilic chronic rhinosinusitis with nasal polyps.

Previous studies have shown that epithelial-to-mesenchymal transition (EMT) in nasal epithelial cells is critical for tissue remodeling of chronic rhinosinusitis with nasal polyps (CRSwNP). However, the precise mechanism underlying the EMT remains poorly understood. This study aimed to investigate the role of interleukin-4 (IL-4)/signal transducer and activator of transcription 6 (STAT6)/interferon regulatory factor 4 (IRF4) signaling pathway on EMT in eosinophilic CRSwNP. We performed quantitative real-time polymerase chain reaction, immunohistochemistry, immunofluorescent staining, and Western blotting to evaluate the expression of STAT6, IRF4, and EMT markers in sinonasal mucosal samples. Effects of IL-4-induced EMT were determined using primary human nasal epithelial cells (hNECs) from patients with eosinophilic CRSwNP. Wound scratch assay, cell morphology, Western blotting, and immunofluorescence cytochemistry were performed to evaluate EMT, and EMT-related markers. Next, human THP-1 monocytic cells were stimulated by phorbolate-12-myristate-13-acetate to differentiate into M0 and were subsequently polarized into M1 with lipopolysaccharide and interferon-γ, M2 with IL-4. The markers of the macrophage phenotype were assessed by Western blotting. The co-culture system was built to explore the interaction between macrophages (THP-1 cells) and hNECs. After co-culture with M2 macrophages, EMT-related markers of primary hNECs were evaluated by immunofluorescence cytochemistry and Western blotting. Enzymelinked immunosorbent assays were used to detect transforming growth factor beta 1 (TGF-β1) in THP-1-derived supernatants. STAT6 and IRF4 mRNA and protein expression were significantly upregulated in both eosinophilic and noneosinophilic nasal polyps compared with control tissues. The expression of STAT6 and IRF4 in eosinophilic nasal polyps was higher than those in noneosinophilic nasal polyps. STAT6 and IRF4 were not only expressed in epithelial cells but also in macrophages. The number of STAT6+CD68+ cells and IRF4+CD68+ cells in eosinophilic nasal polyps was higher than those in noneosinophilic nasal polyps and control tissues. EMT was enhanced in eosinophilic CRSwNP compared to the healthy controls and noneosinophilic CRSwNP. IL-4-stimulated human nasal epithelial cells exhibited EMT characteristics. The hNECs co-cultured with M2 macrophages demonstrated high levels of EMT-related markers. The TGF-β1 level was significantly induced by IL-4 and elevated (M2) rather than control macrophages. The inhibition of STAT6 by AS1517499 reduced the expression of IRF4 in epithelial cells and macrophages and counteracted IL-4-induced EMT in epithelial cells. In eosinophilic nasal polyps, IL-4 induces STAT6 signaling to upregulate IRF4 expression in epithelial cells and macrophages. IL-4 promotes EMT of hNECs through the STAT6/IRF4 signaling pathway. IL-4-induced M2 macrophages enhanced EMT of hNECs. Inhibition of STAT6 can downregulate the expression of IRF4 and suppress the EMT process, thus providing a new strategy for the treatment of nasal polyps.

Eosinophil-mast cell pattern of intraepithelial infiltration as a marker of severity in CRSwNP

Chronic rhinosinusitis with nasal polyps (CRSwNP) is defined as a Type 2 eosinophilic disease, while CRSsNP is considered a Type 1 neutrophilic disease. Since neutrophils are also activated in eosinophilic CRSwNP, the eosinophil–neutrophil dualism has been revaluated. Among the inflammatory cells infiltrating sinus-nasal tissues, the role of mast cells (MCs) is not already recognized, although Clinical-Cytological Grading, which defines the severity of CRSwNP, attributes to mixed eosinophil-MC forms of CRSwNP a greater risk of recurrence. We aimed to examine nasal polyps from both a cytological and histopathological point of view, to evaluate the presence and localization of MCs. Cytological and histological examination of 39 samples of nasal polyps were performed. Immunohistochemistry was used to evaluate the presence of Tryptase + CD117 + MCs, which were counted both in the epithelial layer and in the lamina propria. A statistically significant correlation was found between intraepithelial MCs and CRSwNP severity (p < 0.001) and between the total eosinophil count and the total mast cell count (p < 0.001). Cytological examination and immunohistochemistry were comparable in detecting the presence of intraepithelial MCs (p = 0.002). The histological cut-off of 6 intraepithelial MCs was identified to detect severe CRSwNP (p < 0.001). MCs have been shown to be located in the lamina propria of almost all eosinophilic nasal polyps without significantly affecting their severity. Intraepithelial MCs are associated with greater severity of CRSwNP. Histopathological criteria of the eosinophil-MC form of CRSwNP in addition to the eosinophilic one, should be defined to guarantee patients effective and tailored treatments.

Crocin Inhibits the Type 2 Inflammatory Response Produced by ILC2s in Eosinophilic Nasal Polyps.

Chronic rhinosinusitis with nasal polyps (CRSwNP) is subdivided into type 1 and type 2 inflammatory responses according to the mucosal inflammatory patterns. Crocin can reduce the level of T-helper type 2 cell (Th2) cytokines, such as interleukin-4 (IL-4), and inhibit the nuclear factor kappa-B (NF-κB) signaling pathway. This study aimed to investigate the role of group 2 innate lymphoid cells (ILC2s) in type 2 inflammation in eosinophilic nasal polyps and the inhibitory effect of crocin on this inflammation. Immunohistochemistry and immunofluorescence were used to detect the expression of transcription factors and the infiltration of ILC2s in tissues. An ILC2 stimulation model in vitro was constructed based on IL-33 stimulation and treated with crocin. The explant models were constructed and treated with crocin to detect the expression of type 2 inflammation-related factors. Significantly more GATA-binding protein-3 (GATA3)-positive cells and chemoattractant receptor-homologous molecule expressed on T-helper type 2 cell (CRTH2)-positive cells, but fewer T-box expressed in T cell (T-bet)-positive cells, were found in eosinophilic nasal polyps (NPwEos). The expression levels of GATA3 and CRTH2 were significantly higher in NPwEos. Recombinant IL-33 stimulation increased the expression of GATA3, CRTH2, and type 2 cytokines (IL-4, IL-5, and IL-13) in ILC2s. In an IL-33-stimulated in vitro ILC2 culture model, crocin inhibited the type 2 inflammatory response, especially at lower concentrations (10 µM). The explant organoids of NPwEos were constructed in vitro, and Staphylococcus aureus enterotoxin B (SEB) was used to construct the type 2 inflammation model. Crocin at 10 µM concentration inhibited type 2 inflammation induced by SEB-stimulated explants. Crocin inhibited type 2 inflammation induced by ILC2 activation at low concentrations via inhibiting the activation of NF-κB.

MEX3B inhibits collagen production in eosinophilic nasal polyps by downregulating epithelial cell TGFBR3 mRNA stability.

Although the expression of Mex3 RNA-binding family member B (MEX3B) is upregulated in human nasal epithelial cells (HNECs) predominately in the eosinophilic chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP) subtype, its functions as an RNA binding protein in airway epithelial cells remain unknown. Here, we revealed the role of MEX3B based on different subtypes of CRS and demonstrated that MEX3B decreased the TGF-β receptor III (TGFBR3) mRNA level by binding to its 3' UTR and reducing its stability in HNECs. TGF-βR3 was found to be a TGF-β2-specific coreceptor in HNECs. Knocking down or overexpressing MEX3B promoted or inhibited TGF-β2-induced phosphorylation of SMAD2 in HNECs, respectively. TGF-βR3 and phosphorylated SMAD2 levels were downregulated in CRSwNP compared with controls and CRS without nasal polyps with a more prominent downregulation in the eosinophilic CRSwNP. TGF-β2 promoted collagen production in HNECs. Collagen abundance decreased and edema scores increased in CRSwNP compared with control, again more prominently in the eosinophilic type. Collagen expression in eosinophilic CRSwNP was negatively correlated with MEX3B but positively correlated with TGF-βR3. These results suggest that MEX3B inhibits tissue fibrosis in eosinophilic CRSwNP by downregulating epithelial cell TGFBR3 expression; consequently, MEX3B might be a valuable therapeutic target against eosinophilic CRSwNP.

Analysis of Nasal Polyp Neutrophils by Single Cell RNA-Sequencing

Chronic rhinosinusitis with nasal polyps (CRSwNP) is characterized by type 2 (T2) inflammation. Recent studies, including our own, suggest that neutrophils are also elevated in eosinophilic T2 nasal polyps (NPs) and that elevated neutrophils display an activated phenotype. However, the actual roles of neutrophils in NP pathogenesis in T2 CRSwNP are still largely unclear. In this study, we aimed to reveal the characteristics of NP neutrophils by single cell RNA-Sequencing (scRNA-Seq).

Impact of Chronic Rhinosinusitis with Nasal Polyposis on IL-12 and IL-8.

The pathophysiology of Chronic Rhinosinusitis is coordinated by distinct inflammatory reactions in different individuals. Inflammatory environments with a predominance of Th2 lymphocytes tend also to be rich in eosinophils. These environments are common during the formation of nasal polyps associated with aspirin intolerance, which is also marked by an increase in inflammatory mediators, especially IL-4, IL-5, and IL-13. Despite the significance of these inflammatory mediators, the relevance of IL-12 subunits' presence within eosinophilic nasal polyps, however, has been less studied. The current study aims to evaluate the presence of IL-12 subunits, IL-12p40 and IL-12p70, in eosinophilic nasal polyps and their correlations with IL-8 presence. We compared the concentrations of IL-8, IL12p40, and IL12p70 among samples of eosinophilic nasal polypoid tissue, eosinophilic nasal polypoid tissue associated with aspirin intolerance, and healthy nasal mucosa, using an indirect immunoassay (ELISA) kit. When compared to healthy nasal mucosa, there was a lower concentration of IL-8 in Chronic Rhinosinusitis with Nasal Polyp (CRSwNP) tissue. Aspirin Intolerant polypoid tissue also presented a lower concentration of IL-12 subunits compared to healthy nasal mucosa. There was no significant correlation between IL-8 and IL-12 in the eosinophilic polypoid conditions. In CRSwNP, there is a reduction in IL-8 and IL-12 subunits compared to control, with a lack of correlation between IL-12 and IL-8. The lack of correlation can be justified by a type two inflammatory storm environment.

Central Compartment Atopic Disease and Its Surgical Outcomes: Olfactory Changes and Technical Notes.

Central compartment atopic disease (CCAD) is a recent, novel phenotype of chronic rhinosinusitis. Only a few studies have assessed olfactory function in patients with CCAD. We aimed to investigate olfactory function changes after functional endoscopic sinus surgery (FESS) in patients with CCAD and proposed some surgical techniques to enhance the postoperative olfactory outcomes in such patients. A retrospective cohort study. We collected data from 23 patients (8 men and 15 women) with CCAD who underwent FESS performed by a surgeon in Taiwan, between June 2018 and December 2021. The demographic data, olfactory function, and serum and tissue eosinophil percentages of the included patients were analyzed. The Top International Biotech Smell Identification Test (TIBSIT; Top International Biotech, Taipei, Taiwan) was used to assess olfactory function. Of the 23 patients, most (95%) showed a positive reaction to aeroallergens, and 2 patients (8.7%) had asthma. Ten patients (43.5%) had peripheral eosinophilia, and 9 (39%) had eosinophilic nasal polyps. Moreover, the patients presented with variable olfactory dysfunction; the mean preoperative TIBSIT (pr-TIBSIT) score was 12.8 ± 2.3 (range: 0-43), whereas the mean postoperative TIBSIT (po-TIBSIT) score was 29.2 ± 1.9 (range: 16-44). The po-TIBSIT score was significantly better than the pre-TIBSIT score (paired t test, P < .0001). The improvement in olfactory function was not significantly correlated with the patients' age, serum eosinophil percentages, and nasal polyp eosinophil counts. Our findings indicate that CCAD is significantly associated with olfactory dysfunction and that FESS can effectively improve olfactory function. To optimize postoperative olfactory outcomes, precise removal of polyps from the olfactory cleft without damaging the neuroepithelium is recommended. Our study provides valuable insights into the management of CCAD patients undergoing FESS and can guide surgical decision-making to achieve optimal olfactory function outcomes.

Histone deacetylase activity is a novel target for epithelial barrier defects in patients with eosinophilic chronic rhinosinusitis with nasal polyps.

Studies have independently indicated that eosinophils and histone deacetylases (HDACs) may compromise the integrity of the epithelial barrier in nasal polyps; however, the underlying mechanisms are not clear. In this study, we aimed to investigate the role of eosinophilia and HDACs in regulation of tight junctions (TJs) and nasal epithelial barrier integrity in chronic rhinosinusitis with nasal polyps (CRSwNP) patients. Expression of mRNAs and proteins of TJs and HDACs of biopsy specimens and air-liquid interface (ALI) human nasal epithelial cell cultures (HNECs) from eosinophilic and noneosinophilic CRSwNP patients and healthy controls was assessed. The ALI HNECs were also assessed for changes in transepithelial electrical resistance (TER) and paracellular flux of fluorescein isothiocyanate (FITC)-labelled dextran. Meanwhile, the assessments for the effect of HDAC inhibitor in eosinophilic nasal polyps were also conducted. Decreased TER and increased paracellular flux of FITC-labelled dextran in the ALI cultures were found in both eosinophilic and noneosinophilic CRSwNP, along with irregular, patchy and reduced expression of claudin-1, 4, 7, occludin, zonula occludens (ZO)-1 and ZO-2 and increased expression of HDAC1, 9 and SIRT7 for both ALI culture cells and biopsy specimens, especially for the eosinophilic CRSwNP group. Treatment of eosinophilic CRSwNP ALI-HNECs with an HDAC inhibitor improved the TJs expression and epithelial barrier integrity. Our data suggest that eosinophilia and HDACs influence epithelial barrier function in CRSwNP patients by regulating TJ protein expression. Targeting HDACs with specific inhibitors may be a potential treatment option for patients with eosinophilic CRSwNP.

The Roles of Autophagy, Mitophagy, and the Akt/mTOR Pathway in the Pathogenesis of Chronic Rhinosinusitis with Nasal Polyps.

The pathogenesis of CRSwNP is complex and unclear. CRSwNP is subdivided into two types based on the infiltration of EOSs: eCRSwNP and noeCRSwNP. This study was designed to seek the role of autophagy, mitophagy, and Akt/mTOR pathway in these two subtypes of CRSwNP. This study included 29 patients with CRSwNP and 9 controls. The levels of autophagy, mitophagy, and Akt/mTOR pathway-related proteins in nasal tissues were quantified using western blot analysis. Levels of eosinophilic inflammation-related cytokines in nasal tissues were quantified by enzyme-linked immunosorbent assay. Immunohistochemistry was also used to evaluate autophagy, mitophagy, and Akt/mTOR pathway-related protein expression and distribution in nasal polyps and control tissues. Transmission electron microscopy was used to detect the formation of autophagosomes and mitochondrial autophagosomes. Masson's trichrome and periodic acid–Schiff Alcian blue staining were used to evaluate the severity of tissue remodeling. The expression of p-Akt/Akt and p-mTOR/mTOR was upregulated in patients with eCRSwNP or noeCRSwNP. Beclin 1, PINK1, BNIP3, and FUNDC1 levels were significantly reduced in the nasal polyps of patients with eCRSwNP or noeCRSwNP. Autophagosomes and mitochondrial autophagosomes formed less frequently in the nasal polyps of patients with eCRSwNP or noeCRSwNP. Levels of IL-4, IL-5, IL-13, and ECP and the eotaxins CCL11, CCL24, and CCL26 were elevated in the nasal polyps of patients with eCRSwNP or noeCRSwNP. Tissue remodeling is enhanced in patients with eCRSwNP or noeCRSwNP. The Akt/mTOR pathway, eosinophilic inflammation, and tissue remodeling are activated in the nasal polyps of patients with eCRSwNP or noeCRSwNP. The downregulation of autophagy and mitophagy is also observed in eosinophilic and noneosinophilic nasal polyps. The targeting of mitophagy may provide new therapeutic options for different endotypes of CRSwNP.

Expression and Role of Calcitonin Gene-Related Peptide in Patients With Chronic Rhinosinusitis With Nasal Polyposis

Background and Objectives A recent study revealed that calcitonin gene-related protein (CGRP) plays an important role in inflammatory airway diseases. However, the influence of CGRP on chronic rhinosinusitis (CRS) has not been studied. This study investigated the expression, activity, and potential pathogenic role of CGRP in patients with CRS with nasal polyposis (CRSwNP).Subjects and Method Patients with CRSwNP and control subjects were enrolled. The CRSwNP group was divided according to the presence of eosinophilic polyps and non-eosinophilic polyps. Nasal polyps (NPs) and uncinate tissues (UTs) from patients with CRSwNP and UTs from control subjects were obtained to investigate the expression of α-/β-CGRP and chromogranin A. In addition, the expression patterns of cytokines following exposure to exogenous CGRP were analyzed in dispersed nasal polyp cells (DNPCs) from patients with eosinophilic or non-eosinophilic CRSwNP. The effects of CGRP on lipopolysaccharide (LPS)-induced nuclear factor-kappa light chain enhancer of activated B cells (NF-κB) signaling change were evaluated in THP-1 cells.Results The expression of α-/β-CGRP and number of CGRP-producing cells were significantly higher in NPs from patients with CRSwNP than in UTs from controls. Exogenous CGRP decreased the expression of inflammatory cytokines and increased that of the anti-inflammatory cytokines in DNPCs from patients with eosinophilic nasal polyps (EPs) and also increased the expression of tissue remodeling-related and anti-inflammatory cytokines in DNPCs from patients with non-eosinophilic nasal polyps (N-EPs). CGRP inhibited the nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor (IκB) phosphorylation and NF-κB translocation in LPS-stimulated M1 macrophages.Conclusion CGRP expression in NPs may play a significant role in nasal polypogenesis through inflammatory modulation, and it could be a future target to modulate certain aspects of CRSwNP.

Viral stimulation modulates endotype-related ACE2 expression in eosinophilic chronic rhinosinusitis.

Angiotensin-converting enzyme 2 (ACE2), a receptor targeted by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is highly expressed in the nasal mucosa. Chronic rhinosinusitis (CRS) shows diverse endotypes and is aggravated by viral infection. Whether viral stimulation and CRS endotype influence ACE2 expression remains unclear. We investigated the expression of ACE2 and the transmembrane protease, serine 2 (TMPRSS2), which mediate the entry of SARS-CoV-2 into cells, and assessed polyinosinic:polycytidylic acid (poly[I:C])-induced changes based on CRS endotype. ACE2 and TMPRSS2 expression was evaluated based on CRS phenotype, endotype, and tissue type. Correlations between ACE2/TMPRSS2 expression and inflammatory mediators in nasal polyps (NP) were examined. Air-liquid interface culture experiments were performed to assess the effects of major cytokines or poly(I:C) stimulation on ACE2/TMPRSS2 expression in primary epithelial cells from healthy nasal mucosa, eosinophilic NP (ENP), and non-eosinophilic NP (NENP). In primary nasal epithelial cells, interleukin (IL)-13 decreased ACE2 expression but increased TMPRSS2. Eosinophilic CRS showed lower ACE2 expression than non-eosinophilic CRS, regardless of CRS phenotype. CRS endotype was an independent factor associated with ACE2/TMPRSS2 expression in NP. Serum and tissue eosinophilic marker levels were inversely correlated with ACE2 expression, whereas tissue neutrophilic marker levels and ACE2 expression were positively correlated in NP. ACE2 expression was suppressed in ENP tissues; however, a combination of poly(I:C) and IL-13 induced ACE2/TMPRSS2 upregulation in ENP. ENP tissues have lower ACE2 expression than NENP; however, viral stimulation promotes ACE2/TMPRSS2 upregulation in ENP.