m6A mRNA methylation-mediated MAPK signaling modulates the nasal mucosa inflammatory response in allergic rhinitis.

Background: Allergic rhinitis (AR) is a complex disease in which gene-environment interactions contribute to its pathogenesis. Epigenetic modifications, such as N6-methyladenosine (m6A) modification of mRNA, play important roles in regulating gene expression in multiple physiological and pathological processes. However, the function of m6A modification in AR and the inflammatory response is poorly understood. Methods: We used the ovalbumin (OVA) and aluminum hydroxide to induce an AR mouse model. Nasal symptoms, histopathology, and serum cytokines were examined. We performed combined m6A and RNA sequencing to analyze changes in m6A modification profiles. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and methylated RNA immunoprecipitation sequencing qPCR (MeRIP-qPCR) were used to verify differential methylation of mRNAs and the m6A methylation level. Knockdown or inhibition of Alkbh5 in nasal mucosa of mice was mediated by lentiviral infection or IOX1 treatment. Results: We showed that m6A was enriched in a group of genes involved in MAPK signaling pathway. Moreover, we identified a MAPK pathway involving Map3k8, Erk2, and Nfκb1 that may play a role in the disrupted inflammatory response associated with nasal inflammation. The m6A eraser, Alkbh5, was highly expressed in the nasal mucosa of AR model mice. Furthermore, knockdown of Alkbh5 expression by lentiviral infection resulted in high MAPK pathway activity and a significant nasal mucosa inflammatory response. Our findings indicate that ALKBH5-mediated m6A dysregulation likely contributes to a nasal inflammatory response via the MAPK pathway. Conclusion: Together, our data show that m6A dysregulation mediated by ALKBH5, is likely to contribute to inflammation of the nasal mucosa via the MAPK signaling pathway, suggesting that ALKBH5 is a potential biomarker for AR treatment.

Deciphering the Interplay between the Epithelial Barrier, Immune Cells, and Metabolic Mediators in Allergic Disease.

Chronic exposure to harmful pollutants, chemicals, and pathogens from the environment can lead to pathological changes in the epithelial barrier, which increase the risk of developing an allergy. During allergic inflammation, epithelial cells send proinflammatory signals to group 2 innate lymphoid cell (ILC2s) and eosinophils, which require energy and resources to mediate their activation, cytokine/chemokine secretion, and mobilization of other cells. This review aims to provide an overview of the metabolic regulation in allergic asthma, atopic dermatitis (AD), and allergic rhinitis (AR), highlighting its underlying mechanisms and phenotypes, and the potential metabolic regulatory roles of eosinophils and ILC2s. Eosinophils and ILC2s regulate allergic inflammation through lipid mediators, particularly cysteinyl leukotrienes (CysLTs) and prostaglandins (PGs). Arachidonic acid (AA)-derived metabolites and Sphinosine-1-phosphate (S1P) are significant metabolic markers that indicate immune dysfunction and epithelial barrier dysfunction in allergy. Notably, eosinophils are promoters of allergic symptoms and exhibit greater metabolic plasticity compared to ILC2s, directly involved in promoting allergic symptoms. Our findings suggest that metabolomic analysis provides insights into the complex interactions between immune cells, epithelial cells, and environmental factors. Potential therapeutic targets have been highlighted to further understand the metabolic regulation of eosinophils and ILC2s in allergy. Future research in metabolomics can facilitate the development of novel diagnostics and therapeutics for future application.

Mechanistic study of acupuncture on the pterygopalatine ganglion to improve allergic rhinitis: analysis of multi-target effects based on bioinformatics/network topology strategie.

One of the prevalent chronic inflammatory disorders of the nasal mucosa, allergic rhinitis (AR) has become more widespread in recent years. Acupuncture pterygopalatine ganglion (aPPG) is an emerging alternative therapy that is used to treat AR, but the molecular mechanisms underlying its anti-inflammatory effects are unclear. This work methodically demonstrated the multi-target mechanisms of aPPG in treating AR based on bioinformatics/topology using techniques including text mining, bioinformatics, and network topology, among others. A total of 16 active biomarkers and 108 protein targets related to aPPG treatment of AR were obtained. A total of 345 Gene Ontology terms related to aPPG of AR were identified, and 135 pathways were screened based on Kyoto Encyclopedia of Genes and Genomes analysis. Our study revealed for the first time the multi-targeted mechanism of action of aPPG in the treatment of AR. In animal experiments, aPPG ameliorated rhinitis symptoms in OVA-induced AR rats; decreased serum immunoglobulin E, OVA-sIgE, and substance P levels; elevated serum neuropeptide Y levels; and modulated serum Th1/Th2/Treg/Th17 cytokine expression by a mechanism that may be related to the inhibition of activation of the TLR4/NF-κB/NLRP3 signaling pathway. In vivo animal experiments once again validated the results of the bioinformatics analysis. This study revealed a possible multi-target mechanism of action between aPPG and AR, provided new insights into the potential pathogenesis of AR, and proved that aPPG was a promising complementary alternative therapy for the treatment of AR.

Long non-coding RNA NEAT1 exacerbates NLRP3-mediated pyroptosis in allergic rhinitis through regulating the PTBP1/FOXP1 cascade.

BACKGROUND: Allergic Rhinitis (AR) is a prevalent chronic non-infectious inflammation affecting the nasal mucosa. NLRP3-mediated pyroptosis of epithelial cells plays a pivotal role in AR pathogenesis. Herein, we evaluated the impact of the long non-coding RNA nuclear paraspeckle assembly transcript 1 (lncRNA NEAT1) on NLR family pyrin domain containing 3 (NLRP3)-mediated pyroptosis in AR. METHODS: Nasal inflammation levels in ovalbumin (OVA)-induced AR mice were assessed using HE staining, and NLRP3 expression was evaluated through immunohistochemistry. ELISA was utilized to detect OVA-specific IgE, IL-6, IL-5, and inflammatory cytokines (IL-1ß, IL-18). Human nasal epithelial cells (HNEpCs) stimulated with IL4/IL13 were used to analyze the mRNA and protein levels of associated genes utilizing RT-qPCR and western blot, respectively. Cell viability and pyroptosis were assessed by CCK-8 and flow cytometry. The targeting relationship between NEAT1, PTBP1 and FOXP1 were analyzed by RIP and RNA pull down assays. FISH and IF analysis were performed to assess the co-localization of NEAT1 and PTBP1. RESULTS: In both the AR mouse and cellular models, increased levels of NEAT1, PTBP1 and FOXP1 were observed. AR mice exhibited elevated inflammatory infiltration and pyroptosis, evidenced by enhanced expressions of OVA-specific IgE, IL-6, and IL-5, NLRP3, Cleaved-caspase 1, GSDMD-N, IL-1ß and IL-18. Functional assays revealed that knockdown of PTBP1 or NEAT1 inhibited pyroptosis while promoting the proliferation of IL4/IL13-treated HNEpCs. Mechanistically, NEAT1 directly interacted with PTBP1, thereby maintaining FOXP1 mRNA stability. Rescue assays demonstrated that FOXP1 upregulation reversed the inhibitory effects of silencing NEAT1 or PTBP1 on IL4/IL13-stimulated pyroptosis activation in HNEpCs. CONCLUSION: NEAT1 acts as a RNA scaffold for PTBP1, activating the PTBP1/FOXP1 signaling cascade, subsequently triggering NLRP3-mediated pyroptosis in HNEpCs, and ultimately promoting AR progression. These findings highlight some new insights into the pathogenesis of AR.

An observational analysis on the influence of parental allergic rhinitis, asthma and smoking on exhaled nitric oxide in offspring.

BACKGROUND: Parental allergic diseases and smoking influence respiratory disease in the offspring but it is not known whether they influence fractional exhaled nitric oxide (FeNO) in the offspring. We investigated whether parental allergic diseases, parental smoking and FeNO levels in parents were associated with FeNO levels in their offspring. METHODS: We studied 609 offspring aged 16-47 years from the Respiratory Health in Northern Europe, Spain and Australia generation (RHINESSA) study with parental information from the Respiratory Health in Northern Europe (RHINE) III study and the European Community Respiratory Health Survey (ECRHS) III. Linear regression models were used to assess the association between offspring FeNO and parental FeNO, allergic rhinitis, asthma and smoking, while adjusting for potential confounding factors. RESULTS: Parental allergic rhinitis was significantly associated with higher FeNO in the offspring, both on the paternal and maternal side (percent change: 20.3 % [95%CI 5.0-37.7], p = 0.008, and 13.8 % [0.4-28.9], p = 0.043, respectively). Parental allergic rhinitis with asthma in any parent was also significantly associated with higher offspring FeNO (16.2 % [0.9-33.9], p = 0.037). However, parental asthma alone and smoking were not associated with offspring FeNO. Parental FeNO was not associated with offspring FeNO after full adjustments for offspring and parental factors. CONCLUSIONS: Parental allergic rhinitis but not parental asthma was associated with higher levels of FeNO in offspring. These findings suggest that parental allergic rhinitis status should be considered when interpreting FeNO levels in offspring beyond childhood.

Integration of bioinformatics analysis, molecular docking and animal experiments to study the therapeutic mechanisms of berberine against allergic rhinitis.

Allergic rhinitis is a prevalent inflammatory condition that impacts individuals of all age groups. Despite reports indicating the potential of berberine in alleviating allergic rhinitis symptoms, the specific molecular mechanisms and therapeutic targets of berberine remain unclear. This research aims to explore the pharmacological mechanism of berberine in the treatment of allergic rhinitis through bioinformatic analyses and experimental validation. The research utilized public databases to identify potential targets of berberine. Furthermore, differentially expressed genes (DEGs) related to allergic rhinitis were pinpointed from the GSE52804 dataset. Through bioinformatics techniques, the primary targets were discovered and key KEGG and GO-BP pathways were established. To confirm the therapeutic mechanisms of berberine on allergic rhinitis, an OVA-induced allergic rhinitis model was developed using guinea pigs. We identified 32 key genes responsible for the effectiveness of berberine in treating allergic rhinitis. In addition, five central genes (Alb, Il6, Tlr4, Ptas2, and Il1b) were pinpointed. Further examination using KEGG and GO-BP pathways revealed that the main targets were primarily involved in pathways such as NF-kappa B, IL-17, TNF, and inflammatory response. Molecular docking analysis demonstrated that berberine exhibited strong affinity towards these five key targets. Furthermore, the expression levels of IL-6, TLR4, PTGS2, and IL-1ß were significantly upregulated in the model group but downregulated following berberine treatment. This research has revealed the mechanism through which berberine combats allergic rhinitis and has identified its potential to regulate pathways linked to inflammation. These discoveries provide valuable insights for the development of novel medications for the treatment of allergic rhinitis.

[H3K27 acetylation promotes lncRNA OIP5-AS1 transcription and induces apoptosis of nasal epithelial cells in allergic rhinitis through up-regulation of TLR4].

Objective To investigate the effect of lysine 27 residue of histone H3 (H3K27) acetylation modification on the transcriptional promotion of long noncoding RNA OPA interacting protein 5-antisense RNA 1 (lncRNA OIP5-AS1) and apoptosis of nasal epithelial cells (NECs) in allergic rhinitis (AR) via regulating Toll-like receptor 4 (TLR4). Methods Interleukin-13 (IL-13) was used to treat NECs to establish an AR cell model. Real-time quantitative PCR was utilized to detect the expressions of OIP5-AS1 and TLR4 in nasal mucosal tissues of AR patients and in the in vitro cell model. The concentrations of macrophage colony-stimulating factor (GM-CSF), eotaxin-1, and mucin 5AC (MUC5AC) were detected by ELISA. The apoptosis of NECs was determined by terminal deoxynucleotidyl transferase mediated dUTP-biotin nick end labeling (TUNEL). A dual-luciferase report experiment was carried out to verify the relationship between OIP5-AS1 and TLR4. Chromatin immunoprecipitation (ChIP) assay was performed to verify H3K27 acetylation of histones in the OIP5-AS1 promoter region. Results Compared with healthy controls and untreated NECs, OIP5-AS1 and TLR4 were both up-regulated in nasal mucosal tissues from AR patients and IL-13-stimulated NECs. Knockdown of OIP5-AS1 decreased the level of TLR4 in IL-13-treated NECs, while overexpression of OIP5-AS1 increased the level of TLR4. Inhibition of OIP5-AS1 reduced the apoptosis rate, and inhibited the secretion of GM-CSF, eotaxin-1, and MUC5AC from IL-13-treated NECs, while overexpression of TLR4 partially reversed the effects of OIP5-AS1 knockdown on NEC apoptosis and the secretion of GM-CSF, eotaxin-1, and MUC5AC. In addition, H3K27 acetylation was markedly enriched in the promoter region of OIP5-AS1, and H3K27 acetylation promoted the expression of OIP5-AS1 in IL-13-treated NECs. Conclusion H3K27 acetylation promotes OIP5-AS1 transcription and induces NEC apoptosis in AR via upregulation of TLR4.

Nasal mucosal fibroblasts produce IL-4 to induce Th2 response.

Th2 polarization is essential for the pathogenesis of allergic rhinitis (AR). Th2 polarization's mechanism requires further understanding. IL-4 is the primary cytokine involved in Th2 response. Fibroblasts play a role in immune regulation. This study aims to elucidate the role of nasal mucosal fibroblast-derived IL-4 in the induction of Th2 responses. Nasal mucosal tissues were obtained from surgically removed samples from patients with nasal polyps, whether with or without AR. Fibroblasts were isolated from the tissues by flow cytometry cell sorting, and analyzed by RNA sequencing (RNAseq). The data from RNAseq showed that nasal fibroblasts expressed genes of GATA3, CD80, CD83, CD86, STAT6, IL2, IL4, IL5, IL6, IL13 and costimulatory factor. The data were verified by RT-qPCR. The level of gene activity was positively correlated with those of AR-related cytokines present in nasal secretions. Nasal fibroblasts release IL-4 upon activation. Nasal fibroblasts had the ability to transform naive CD4+ T cells into Th2 cells, which can be eliminated by inhibiting IL-4 receptor or CD28 in CD4+ T cells. To sum up, nasal mucosal fibroblasts produce IL-4, which can induce Th2 cell development. The data implicate that nasal fibroblasts are involved in the pathogenesis of nasal allergy.

Acupuncture at "Die E acupoint" alleviates inflammatory reaction via inhibiting TLR4/MyD88/NF-κB signaling in rats with allergic rhinitis. / 基于Tollæ ·å—ä½“4/é«“æ ·åˆ†åŒ–å› å­88/æ ¸è½¬å½•å› å­κB信号通路探讨针刺"è¶è ­ç©´"æ”¹å–„å˜åº”æ€§é¼»ç‚Žå¤§é¼ å ç–«ç‚Žæ€§ååº”çš„æœºåˆ¶.

OBJECTIVES: To observe effects of acupuncture at "Die E acupoint" on the protein expression levels of Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), nuclear transcription factor κB (NF-κB), transcription factor T-bet (T-bet), and GATA-binding protein-3 (GATA-3) in the nasal mucosa and the serum contents of related inflammatory cytokines in rats with allergic rhinitis, so as to explore the mechanism of acupuncture in treating allergic rhinitis. METHODS: Twenty-four healthy SD rats were randomly divided into blank, model, acupuncture, and sham acupuncture groups, with 6 rats in each group. The rat model of allergic rhinitis was established by using ovalbumin induction. The rats in the acupuncture group received bilateral acupuncture at the "Die E acupoint" with a depth of 15-20 mm, while the rats in the sham acupuncture group received only sham acupuncture (light and shallow acupunture of the skin at the "Die E acupoint" ). Both interventions were performed once daily for a total of 6 days. Behavioral scores of rats in each group were recorded. Pathological changes of nasal mucosa were observed by H.E. staining. Serum contents of IgE, ovalbumin-specific IgE (OVA-sIgE), interferon(IFN)-γ, interleukin(IL)-4, IL-10 and IL-17 were measured by ELISA and the protein expression levels of T-bet, GATA-3, TLR4, MyD88 and NF-κB p65 in the nasal mucosa were detected by Western blot. RESULTS: After modeling, compared with the blank group, rats in the model group showed increased behavioral scores, serum IgE, OVA-sIgE, IL-4, and IL-17 contents, and nasal mucosal GATA-3, TLR4, MyD88, and NF-κB p65 protein expression levels (P<0.05), whereas the contents of serum IFN-γ, IL-10 and the protein expression level of T-bet in the nasal mucosa were decreased (P<0.05). Comparison between the EA and model groups showed that acupuncture intervention can decrease the behavioral scores of rats with allergic rhinitis, the contents of serum IgE, OVA-sIgE, IL-4, IL-17, and the protein expression levels of GATA-3, TLR4, MyD88, and NF-κB p65 in the nasal mucosa (P<0.05), and up-regulate the contents of serum IFN-γ, IL-10, and the nasal mucosal T-bet protein expression level. Sham acupuncture did not have a significant modulating effect on the above indicators. Inflammatory infiltration of nasal mucosa was seen in the model group and sham acupuncture, and the inflammatory reaction was milder in the acupuncture group. CONCLUSIONS: Acupuncture at "Die E acupoint" can alleviate the symptoms of allergic rhinitis and suppress the inflammation of nasal mucosa in rats, which may be related to inhibiting the TLR4/MyD88/NF-κB signaling and balancing the levels of cytokines of Th1/Th2 and Treg/Th17, and T-bet/GATA-3.

Sex Dimorphism in Pain Threshold and Neuroinflammatory Response: The Protective Effect of Female Sexual Hormones on Behavior and Seizures in an Allergic Rhinitis Model.

Our previous research demonstrated that allergic rhinitis could impact behavior and seizure threshold in male mice. However, due to the complex hormonal cycles and hormonal influences on behavior in female mice, male mice are more commonly used for behavioral tests. In this study, we aimed to determine whether these findings were replicable in female mice and to explore the potential involvement of sexual hormones in regulating neuroinflammation in an allergic model. Our results indicate that pain threshold was decreased in female mice with allergic rhinitis and the levels of IL-23/IL-17A/IL-17R were increased in their Dorsal root ganglia. However, unlike males, female mice with AR did not display neuropsychological symptoms such as learning and memory deficits, depression, and anxiety-like behavior. This was along with decreased levels of DNA methyl transferase 1 (DNMT1) and inflammatory cytokines in their hippocampus. Ovariectomized mice were used to mitigate hormonal effects, and the results showed that they had behavioral changes and neuroinflammation in their hippocampus similar to male mice, as well as increased levels of DNMT1. These findings demonstrate sex differences in how allergic rhinitis affects behavior, pain sensitivity, and seizure thresholds. Furthermore, our data suggest that DNMT1 may be influenced by sexual hormones, which could play a role in modulating inflammation in allergic conditions.

MiR-4454 in Combined Allergic Rhinitis and Asthma Syndrome (CARAS): Clinical significance and mechanistic insights into airway inflammation.

Abnormal expression of non-coding microRNA is associated with the development of combined allergic rhinitis and asthma syndrome (CARAS). However, the function of miR-4454 in CARAS is unknown. Our study aimed to reveal the clinical significance and related mechanism of miR-4454 in CARAS. Blood samples from 38 cases of CARAS and 43 cases of healthy subjects were collected to detect the expression of miR-4454. House dust mite (HDM) sensitization and challenge-induced bronchial epithelial cells to simulate the asthma state model in vitro, miR-4454 mimics and inhibitor transfection to detect the expression level of pro-inflammatory cytokines, cell survival rate and migration ability, flow cytometry and western blot (WB) Detection of cell cycle, apoptosis and inflammation-related protein levels. Compared with healthy controls, the expression of miR-4454 in the blood of CARAS patients was significantly up-regulated, and IL-6 and IL-8 were significantly up-regulated in the HDM treatment group, indicating that the model induction was successful. After overexpression of miR-4454, cell proliferation and migration in the HDM-treated group were significantly inhibited, and the levels of early apoptosis and inflammation-related proteins (IL-17, IL-17RD, TNF-α, GCSF and NF-κB) were increased High; after inhibiting miR-4454, cell proliferation and migration were significantly enhanced, and the levels of apoptosis and inflammation-related proteins were decreased. This study found that inhibiting the expression of miR-4454 can improve HDM-induced cell injury, which may be related to miR-4454 regulating the activation of IL-17/NF-кB inflammatory axis.

IL-6 mediates olfactory dysfunction in a mouse model of allergic rhinitis.

BACKGROUND: Immune-inflammatory response is a key element in the occurrence and development of olfactory dysfunction (OD) in patients with allergic rhinitis (AR). As one of the core factors in immune-inflammatory responses, interleukin (IL)-6 is closely related to the pathogenesis of allergic diseases. It may also play an important role in OD induced by diseases, such as Sjögren's syndrome and coronavirus disease 2019. However, there is no study has reported its role in OD in AR. Thus, this study aimed to investigate the role of IL-6 in AR-related OD, in an attempt to discover a new target for the prevention and treatment of OD in patients with AR. METHODS: Differential expression analysis was performed using the public datasets GSE52804 and GSE140454 for AR, and differentially expressed genes (DEGs) were obtained by obtaining the intersection points between these two datasets. IL-6, a common differential factor, was obtained by intersecting the DEGs with the General Olfactory Sensitivity Database (GOSdb) again. A model of AR mice with OD was developed by sensitizing with ovalbumin (OVA) to verify the reliability of IL-6 as a key factor of OD in AR and explore the potential mechanisms. Furthermore, a supernatant and microglia co-culture model of nasal mucosa epithelial cells stimulated by the allergen house dust mite extract Derp1 was established to identify the cellular and molecular mechanisms of IL-6-mediated OD in AR. RESULTS: The level of IL-6 in the nasal mucosa and olfactory bulb of AR mice with OD significantly increased and showed a positive correlation with the expression of olfactory bulb microglia marker Iba-1 and the severity of OD. In-vitro experiments showed that the level of IL-6 significantly increased in the supernatant after the nasal mucosa epithelial cells were stimulated by Derp1, along with significantly decreased barrier function of the nasal mucosa. The expression levels of neuroinflammatory markers IL-1ß and INOS increased after a conditioned culture of microglia with the supernatant including IL-6. Then knockdown (KD) of IL-6R by small interfering RNA (siRNA), the expression of IL-1ß and INOS significantly diminished. CONCLUSION: IL-6 plays a key role in the occurrence and development of OD in AR, which may be related to its effect on olfactory bulb microglia-mediated neuroinflammation.

LncRNA ZFAS1 Alleviated NLRP3 Inflammasome-Mediated Pyroptosis through Regulating miR-96-5p/Smad7 Signaling in Allergic Rhinitis.

INTRODUCTION: The NLR family pyrin domain containing 3 (NLRP3)-mediated pyroptosis was positively correlated with the allergic rhinitis progression and was reported to be regulated by SMAD family member 7 (Smad7). Bioinformatics analysis revealed that Smad7 might be targeted by miR-96-5p, and miR-96-5p might be targeted by long noncoding RNA zinc finger antisense 1 (ZFAS1). However, the effects and regulatory mechanisms of the ZFAS1/miR-96-5p/Smad7 functional axis in allergic rhinitis have not been investigated. METHODS: Human nasal mucosa epithelial cell line RPMI 2650 and C57BL/6 mice were obtained for in vitro and in vivo studies. Dual-luciferase reporter assay and RNA immunoprecipitation were implemented for detecting molecular interactions. Cell counting kit-8 and flow cytometry were used for measuring cell viability and pyroptosis. ELISA was obtained for monitoring cytokine secretion. RT-qPCR and Western blot were examined for determining RNA and protein expression. RESULTS: In vitro studies revealed that ZFAS1 was downregulated in interleukin (IL)-13-treated RPMI 2650 cells, while overexpression of ZFAS1 enhanced cell viability and inhibited NLRP3-mediated pyroptosis and inflammatory response. ZFAS1 directly inhibited miR-96-5p to suppress NLRP3-mediated pyroptosis in IL-13-treated RPMI 2650 cells. MiR-96-5p bound to the 3'-untranslated region of Smad7 and knockdown of Smad7 significantly reversed the effects of miR-96-5p depletion. Moreover, in vivo experiments further confirmed the findings of in vitro studies and showed ZFAS1 overexpression or miR-96-5p inhibition alleviated allergic rhinitis in vivo. CONCLUSION: ZFAS1 downregulated the expression of miR-96-5p to upregulate Smad7 level, which subsequently inhibited NLRP3-mediated pyroptosis and inflammatory response to ameliorate allergic rhinitis.

Nasal hyperreactivity in allergic rhinitis and chronic rhinosinusitis with polyps: a role for neuronal pathways.

BACKGROUND: Nasal hyperreactivity (NHR) is prevalent in all chronic upper airway inflammatory phenotypes, including allergic rhinitis (AR) and chronic rhinosinusitis with nasal polyps (CRSwNP). Although NHR in patients with non-allergic rhinitis is mediated by neuronal pathways, AR and CRSwNP are mainly characterized by type 2 inflammation. METHODS: Eighteen healthy controls and 45 patients with symptomatic AR/CRSwNP underwent a cold, dry air (CDA) provocation test for objective diagnosis of NHR. Before and after, questionnaires were filled out and nasal secretions and biopsies were collected. Markers for neurogenic inflammation (substance P, calcitonin gene-related peptide, neurokinin A), epithelial activation (IL-33), and histamine were measured in secretions by ELISA; and expression of neuronal markers PGP9.5, TRPV1, and TRPM8 was studied in biopsies by RT-q-PCR. Effects of histamine on TRPV1/A1 were studied with Ca2+-imaging using murine trigeminal neurons. RESULTS: CDA-provocation reduced peak nasal inspiratory flow (PNIF) of patients with subjective NHR but not of non-NHR controls/patients CDA-provocation reduced peak nasal inspiratory flow (PNIF) of patients with subjective NHR but not of non-NHR controls/patients. Subjective (subjectively reported effect of CDA) and objective (decrease in PNIF) effects of CDA were significantly correlated. Levels of neuropeptides and histamine in nasal secretions and mRNA expression of PGP9.5, TRPV1, and TRPM8 correlated with CDA-induced PNIF-reduction. CDA-provocation induced an increase in IL-33-levels. Both TRPV1 and TRPA1 expressed on afferent neurons were sensitized by exposure to histamine. CONCLUSION: NHR is not an on/off phenomenon but spans a continuous spectrum of reactivity. A neurogenic inflammatory background and increased histamine-levels are risk factors for NHR in AR/CRSwNP.

Quercetin-crosslinked chitosan nanoparticles: a potential treatment for allergic rhinitis.

Allergic rhinitis (AR) remains a major health problem worldwide. Compared with traditional oral drugs, nasal administration avoids first-pass metabolism and achieve faster and more effective efficacy. In this study, we used the ion crosslinking method to prepare quercetin-chitosan nasal adaptive nanomedicine (QCS) delivery system and evaluated in the treatment of allergic rhinitis mice models. The obtained positively charged nanoparticles with a particle size of 229.2 ± 0.2 nm have excellent characteristics in encapsulation efficiency (79.604%), drug loading rate (14.068%), drug release (673.068 µg) and stability(> 7 days). Excitingly, QCS treatment significantly reduced the number of sneezing and nasal rubbing events in AR mice, while reducing the levels of inflammatory factors such as immunoglobulin E (IgE), interleukin (IL)-17, tumor necrosis factor (TNF)-α, and (IL)-6 to alleviate AR symptoms. Hematoxylin-eosin (HE) staining also showed the damaged nasal mucosa was improved. These experimental results suggest that QCS can effectively suppress allergic inflammation in a mouse model and hold promise as a therapeutic option for allergic rhinitis.

15-Hydroxyeicosatrienoic acid induces nasal congestion by changing vascular functions in mice.

BACKGROUND: Nasal congestion in allergic rhinitis (AR) is caused by vascular hyperpermeability and vascular relaxation of the nasal mucosa. We previously detected high levels of a lipoxygenation metabolite of dihomogammalinolenic acid, 15-hydroxy-8Z,11Z,13E-eicosatrienoic acid (15-HETrE) in the nasal lavage fluid of AR model mice. Here, we investigated the effects of 15-HETrE on vascular functions associated with nasal congestion. METHODS: We measured 15-HETrE levels in the nasal lavage fluid of ovalbumin-induced AR model mice and nasal discharge of patients with AR. We also assessed nasal congestion and vascular relaxation in mice. Vascular contractility was investigated using isolated mouse aortas. RESULTS: Five ovalbumin challenges increased 15-HETrE levels in AR model mice. 15-HETrE was also detected in patients who exhibiting AR-related symptoms. Intranasal administration of 15-HETrE elicited dyspnea-related behavior and decreased the nasal cavity volume in mice. Miles assay and whole-mount immunostaining revealed that 15-HETrE administration caused vascular hyperpermeability and relaxation of the nasal mucosa. Intravital imaging demonstrated that 15-HETrE relaxed the ear vessels that were precontracted via thromboxane receptor stimulation. Moreover, 15-HETrE dilated the isolated mouse aortas, and this effect was attenuated by K+ channel inhibitors and prostaglandin D2 (DP) and prostacyclin (IP) receptor antagonists. Additionally, vasodilatory effects of 15-HETrE were accompanied by an increase in intracellular cAMP levels. CONCLUSIONS: Our results indicate that 15-HETrE, whose levels are elevated in the nasal cavity upon AR, can be a novel lipid mediator that exacerbates nasal congestion. Moreover, it can stimulate DP and IP receptors and downstream K+ channels to dilate the nasal mucosal vasculature.

Neutrophil extracellular traps in upper respiratory tract secretions: insights into infectious and allergic rhinitis.

Introduction: Neutrophil extracellular traps (NETs) are structures released by neutrophils in response to various infections. NETs have a biocidal role and have been demonstrated to be effective against bacteria, fungi, viruses, and parasites. Depending on the situation, NETs can protect the host from pathogen invasion or contribute to the development of autoimmune diseases such as cystic fibrosis and rheumatoid arthritis. In this study, we aimed to investigate the occurrence of NET as one of the components in upper respiratory tract secretions in infectious and allergic diseases. Methods: Nasal mucus was collected from donors diagnosed with infectious rhinitis or allergic rhinitis. The extracellular DNA content was determined using SytoxGreen staining, and the total protein pool was determined using the microBCA method. Micrococcal nuclease was used to digest the samples and ELISA was employed to identify the NET proteins. The enzymatic activity of elastase was determined. Results: Our findings showed that nasal mucus collected from patients with infectious rhinosinusitis contained extracellular DNA that could come from a variety of sources, responsible for increasing the density and viscosity of secretions, as well as NETs proteins. The identified enzymatic activity of NET elastase indicates the possible irritation of nasal tissues. However, the DNA content was not identified in the samples from allergic patients. In addition, we have shown in preliminary studies that therapy using N-acetylcysteine can liquefy nasal secretions. Discussion: The study suggests that the composition of nasal mucus varies according to the cause of mucosal irritation. The presence of DNA and NET proteins can have severe consequences for the therapeutic process prolonging treatment. The low viscosity of nasal mucus in allergic patients facilitates mucosal flushing and the removal of allergens. Understanding the occurrence and role of NETs in various respiratory diseases is critical for developing effective treatment strategies that consider the complex interaction between the immune system and pathogens. The results of this study suggest that NETs may be present in upper respiratory tract secretions with an infectious background, supporting basic defense mechanisms using eosinophils and EETs. Further research is needed to explore the potential of NETs as a therapeutic target in respiratory diseases.

[Upregulation of IL-18 expression in blood CD4+ Th2 cells of patients with allergic rhinitis].

Objective To investigate the expressions of IL-18, IL-18 binding protein isoform a (IL-18BPa) and IL-18 receptor α (IL-18Rα) in blood CD4+ Th2 cells of patients with allergic rhinitis (AR) and the effects of allergens on their expressions. Methods Blood samples of AR patients and healthy control subjects (HCs) were collected. Peripheral blood mononuclear cells (PBMCs) and CD4+ T cells sorted by immunomagnetic beads were stimulated by crude extract of Artemisia sieversiana wild allergen (ASWE), Platanus pollen (PPE) and house dust mite extract (HDME). Flow cytometry was used to detect the expression of IL-18, IL-18BPa and IL-18Rα in CD4+ Th2 cells, and BioPlex was used to detect the level of plasma IL-4 and analyze its correlation with the proportion of IL-18+ Th2 cells. Results Compared with HCs, the proportion of IL-18+ cells was increased in Th2 cells of AR patients; MFI of IL-18 was increased, while that of IL-18Rα was decreased. Moreover, allergens induced IL-18 and IL-18Rα expression in sorted CD4+ Th2 cells of HCs and induced IL-18Rα in that of AR patients. Additionally, elevated plasma IL-4 level was found in AR patients, which was moderately correlated with the percentage of IL-18+ Th2 cells. Conclusion Allergens may be involved in the pathogenesis of AR by inducing expression of IL-18 in peripheral blood CD4+ Th2 cells.