Denervation of nasal mucosa induced by posterior nasal neurectomy suppresses nasal secretion, not hypersensitivity, in an allergic rhinitis rat model

Pathogen-Mimicking Nanoparticles Based on Rigid Nanomaterials as an Efficient Subunit Vaccine Delivery System for Intranasal Immunization

Despite the safety profile of subunit vaccines, the inferior immunogenicity hinders their application in the nasal cavity. This study introduces a novel antigen delivery and adjuvant system utilizing mucoadhesive chitosan-catechol (Chic) on silica spiky nanoparticles (Ssp) to enhance immunity through multiple mechanisms. The Chic functionalizes the Ssp surface and incorporates with SARS-CoV-2 spike protein receptor-binding domain (RBD) and toll-like receptor (TLR)9 agonist unmethylated cytosine-guanine (CpG) motif, forming uniform virus-like nanoparticles (Ssp-Chic-RBD-CpG) via electrostatic and covalent interactions. Ssp-Chic-RBD-CpG, mimicking the morphology and function of inactive virions, effectively prolongs the retention time of RBD in the nasal mucosa by 3.92-fold compared to RBD alone, enhances the maturation of dendritic cells (DCs), and facilitates the antigen trafficking to the draining lymph nodes, which subsequently induces a stronger mucosal immunity. Mechanistically, the enhanced chemokine chemokine (C-C motif) ligand 20 (CCL20)-driven DCs recruitment and maturation by Ssp-Chic-RBD-CpG are evidenced by a cell co-culture model. In addition, the overexpression of TLR4/9 and activation of MYD88/NF-κB signaling pathway in activation of DCs are observed. Proof of principle is obtained for RBD, but similar delivery mechanisms can be applied in other protein-based subunit vaccines as well when intranasal administration is needed.

Mucoadhesive chitosan-catechol as an efficient vaccine delivery system for intranasal immunization

The mucosal barrier and scavenging effect of the mucosal layer are two main obstacles in inducing mucosal immunization. To overcome these obstacles, we synthesized a bio-inspired mucoadhesive material, chitosan-catechol (ChiC), for surface modification of inactive porcine epidemic diarrhea virus (PEDV). Studies have revealed that PEDV particles can be facilely and mildly modified by Chi-C forming Chi-C-PEDV nanoparticles (Chic-Ps) through the covalent and electrostatic bond, which effectively prolongs the retention time of PEDV in the nasal mucosa. The cell co-culture model demonstrated that Chic-Ps exhibit enhanced recruitment of dendritic cells via the secretion of stimulating chemokine CCL20 and improving antigen permeability by disruption the distribution of ZO-1 protein in epithelial cells. Additionally, the flow cytometry (FCM) analysis revealed that Chic-Ps facilitate trafficking to lymph nodes and induce stronger cellular and humoral immune responses compared to unmodified PEDV. Notably, Chic-Ps induced a higher level of PEDV neutralizing antibody was induced by Chic-Ps in the nasal washes, as confirmed by a plaque reduction neutralization test. These results demonstrate that Chi-C is a promising nasal delivery system for vaccines. Proof of principle was obtained for inactivated PEDV, but similar delivery mechanisms could be applied in other vaccines when intranasal administration is needed.

Comparing The Effects of Botulinum toxin-A and multiple surgical parasympathectomy on treatment of allergic rhinitis

OBJECTIVE

Allergic rhinitis (AR) is a common disease with a recent increasing in prevalence. Traditional treatment strategies of AR, sometimes, show limited effectiveness and side effects. Intranasal injection of Botulinum toxin type A (BTX-A) and multiple postganglionic parasympathectomy of pterygopalatine ganglion (PPG) are among the increasingly used alternative treatment options of AR. In this study, we compared the early efficacy of BTX-A and multiple surgical parasympathectomy (MSP) on treatment of uncontrolled AR.

METHODS

Sixty patients who were diagnosed with uncontrolled AR, were recruited to the study. Participants randomly underwent either intranasal injection of BTX-A (45 IU in each nostril) (Group A) or bilateral MSP (Group B). All patients were evaluated in terms of nasal hypersecretions, congestion and sneezing with visual analogue scale prior to treatment and at weeks 1, 2, 4, 8, 12 and 6 months during the follow-up period.

RESULTS

A significant difference in the degree of nasal hypersecretions and sneezing could be identified in both groups before and after the interventions. Although the significant efficacy on sneezing was documented in group A and B only in the first 4 and 8 weeks, respectively, such efficacy on nasal hypersecretions extended for 12 weeks in group A and throughout the follow-up period in group B. Nasal congestion did not differ significantly in both groups.

CONCLUSION

Both BTX-A and MSP, in patients with uncontrolled AR, may be a long-lasting therapeutic option for the treatment of nasal hypersecretions, but not as effective as for sneezing and nasal congestion.

Effect of Silver Nitrate Cauterisation of Nasal Mucosa on Quality-of-Life and Histology in Patients with Intractable Chronic Rhinitis

Patients with chronic rhinitis causing intractable sneezing which is non-responsive to conventional medication require alternative therapies. The aim of the study was to ascertain the effect of topical 10% silver nitrate solution on the inferior turbinate mucosa as well as quality of life in such patients. Patients with severe chronic rhinitis who failed conventional therapy had application of 10% silver nitrate solution to inferior turbinate mucosa. The number of sneezes/day and mini Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) score was noted before and 8 to 16 weeks after treatment. Pre- and post treatment turbinate biopsies were performed to assess histological changes. At baseline, 67 patients had a mean of 36.6 sneezes/day and mean mini RQLQ score of 4.0 ± 0.7. Pre-treatment biopsies showed epithelial denudation and hyalinization of basement membrane. Following 10% silver nitrate application, 64/67 (95.5%) patients showed significant reduction in number of sneezes both at 1 week (p < 0.001) and 8-16 weeks (mean = 5.5 ± 7.8; p < 0.001). Post- treatment mean global mini RQLQ score was also significantly reduced (mean = 1.3 ± 1.1; p < 0.001). A single application was sufficient in 70.1% patients. There were no complications. Squamous metaplasia (p = 0.005) and epithelial hyperplasia (p = 0.013) as well as epithelial and basement membrane restoration occurred following therapy. 10% silver nitrate solution application is an effective and safe office- based procedure which significantly reduces sneezing improves QoL with corresponding histological changes.

Adverse Events Associated With ClariFix Posterior Nasal Nerve Cryoablation: A MAUDE Database Analysis

Posterior nasal nerve (PNN) cryoablation is a novel surgical technique used to address chronic rhinitis. The purpose of this study is to review the medical device reports (MDRs) submitted to the Food and Drug Administration's (FDA) Manufacturer and User Device Facility Experience (MAUDE) database to identify adverse events related to the use of ClariFix, a device designed for office-based cryosurgical ablation of the PNN. A total of 12 adverse events associated with ClariFix from January 2017 to August 2020 were identified and analyzed. The most common adverse events associated with ClariFix PNN cryoablation include epistaxis and nasal swelling. Further studies are needed to clarify whether PNN cryoablation is associated with epistaxis in certain populations.

Laser ablation of posterior nasal nerves for rhinitis

BACKGROUND

Posterior nasal nerve (PNN) surgery, Radiofrequency (RF), and cryoablation have been described as alternative treatments for allergic and vasomotor rhinitis. We hypothesize that endoscopic (diode) laser ablation (ELA) is effective and less invasive than previously described methods.

METHODS

An IRB approved prospective study was performed. Thirty-two patients with chronic rhinitis and nasal congestion resistant to medical management were recruited. Total Nasal Symptom Score (TNSS) measurements were used to assess symptom severity and treatment outcomes. ELA was performed bilaterally in the clinic with a 940 nm diode laser with CW 5 W output, under topical/local anesthesia in 21 patients, while the remaining 11 were treated under sedation in the operating room. The 400-micron uninitiated diode laser fiber tip with a malleable protective shaft was specially designed for PNN ablation. The fiber was pre-shaped according to the intranasal anatomy and endoscopically advanced toward the posterior middle meatus. Patients were followed up for the first 90 days after treatment.

RESULTS

ELA was successfully completed in 97% of patients. No crusting, epistaxis, or other complications were observed. One patient could not be treated in the office due to limited endoscopic access. TNSS was reduced significantly after30 and 90 days (mean ± SD: 6.0 ± 0.7 prior to ablation, 2.3 ± 0.4 at 90 days, p < .001). Rhinitis and congestion scores decreased at 30 and 90 days after treatment compared to the baseline (p < .001).

CONCLUSION

ELA of the PNN region is safe and well tolerated both in the office and ambulatory settings. Symptom scores were significantly decreased after 30 and 90 days. This new minimally invasive method appears to be a promising treatment method.

Effect of posterior nasal neurectomy on the suppression of allergic rhinitis

OBJECTIVES

Recent guidelines have revealed that allergic rhinitis (AR) impairs quality of life. Neuropeptides play a central role in AR. The aim of this study was to determine the efficacy of posterior nasal neurectomy (PNN) for the treatment of AR and for the suppression of neuropeptides and type 2 cytokine expression.

METHODS

In total, 77 patients undergoing PNN were recruited. Subjective symptoms, including sneezing and rhinorrhea, were elicited with a questionnaire using a 10 cm visual analogue scale (VAS). Nasal lavage fluid taken from a random sample of 17 patients both preoperatively and 1 year postoperatively was screened with enzyme-linked immunosorbent assays.

RESULTS

Postoperative rhinorrhea (6.03 ± 1.31vs 2.12 ± 1.40, P < 0.001) and sneezing (5.53 ± 1.25vs 2.04 ± 1.29, P < 0.001) were significantly improved relative to the preoperative levels; the mean SP and NPY concentrations in the nasal lavage fluid were 91.6 ± 20.9 pg/ml and 71.5 ± 10.5 pg/ml, which decreased significantly to 52.9 ± 16.7 pg/ml and 31.8 ± 8.2 pg/ml, respectively, and the mean periostin and IL-5 concentrations were 215.2 ± 87.7 pg/ml and 984.5 ± 181.8 pg/ml, which decreased significantly to 146.1 ± 70.1 pg/ml and 281.6 ± 74.0 pg/ml, respectively.

CONCLUSIONS

PNN was safe and well tolerated, and the symptom (sneezing and rhinorrhea) scores were significantly decreased by 1 year postoperatively.

Effects of Cigarette Smoke on the Nasal Respiratory and Olfactory Mucosa in Allergic Rhinitis Mice

Objective

Cigarette smoke (CS) exposure reportedly enhances allergic airway inflammation. However, some studies have shown an association between current cigarette smoke exposure and a low risk for allergic rhinitis. Thus, the impact of CS exposure on allergic rhinitis remains poorly understood. The purpose of this study was to investigate the effects of CS on the respiratory mucosa (RM) and the olfactory epithelium (OE) of mice with allergic rhinitis, as the effects may differ depending on the nasal histological compartments.

Methods

Eight-week-old male BALB/c mice were used for this study. We developed a mouse model of smoking by intranasally administering 10 doses of a CS solution (CSS), and a mouse model of allergic rhinitis by sensitization with intraperitoneal ovalbumin (OVA) injection and intranasal challenge with OVA. We examined the effects of CS on the nasal RM and OE in mice with or without allergic rhinitis using histological, serum, and genetic analyses. First, we examine whether CSS exposure induces allergic responses and then, examined allergic responses in the OVA-sensitized allergic rhinitis mice with or without CSS exposure.

Results

Short-term CSS administration intensified allergic responses including increased infiltration of eosinophils and inflammatory cells and upregulation of interleukin-5 expression in the nasal RM of OVA-immunized mice, although only CSS induced neither allergic responses nor impairment of the RM and OE. Notably, repetitive OVA-immunization partially impaired the OE in the upper-lateral area, but CSS administration did not reinforce this impairment in OVA-induced allergic mice.

Conclusion

Short-term CSS exposure strengthened allergic responses in the nasal RM and did not change the structure of the OE. These results suggest that patients with allergic rhinitis could experience exacerbation of allergic symptoms after CS exposure.

Dietary Omega-3 Fatty Acid Dampens Allergic Rhinitis via Eosinophilic Production of the Anti-Allergic Lipid Mediator 15-Hydroxyeicosapentaenoic Acid in Mice

The metabolism and generation of bioactive lipid mediators are key events in the exertion of the beneficial effects of dietary omega-3 fatty acids in the regulation of allergic inflammation. Here, we found that dietary linseed oil, which contains high amounts of alpha-linolenic acid (ALA) dampened allergic rhinitis through eosinophilic production of 15-hydroxyeicosapentaenoic acid (15-HEPE), a metabolite of eicosapentaenoic acid (EPA). Lipidomic analysis revealed that 15-HEPE was particularly accumulated in the nasal passage of linseed oil-fed mice after the development of allergic rhinitis with the increasing number of eosinophils. Indeed, the conversion of EPA to 15-HEPE was mediated by the 15-lipoxygenase activity of eosinophils. Intranasal injection of 15-HEPE dampened allergic symptoms by inhibiting mast cell degranulation, which was mediated by the action of peroxisome proliferator-activated receptor gamma. These findings identify 15-HEPE as a novel EPA-derived, and eosinophil-dependent anti-allergic metabolite, and provide a preventive and therapeutic strategy against allergic rhinitis.

The effects of resection of the peripheral branches of the posterior nasal nerves in the inferior turbinate, with special focus on olfactory dysfunction

OBJECTIVE

There are few detailed studies about peripheral branch resection of the posterior nasal nerves in the inferior turbinate; thus, this study aimed to investigate this.

METHODS

Patients who underwent submucosal turbinoplasty with or without resection of the peripheral branches of posterior nasal nerves in the inferior turbinate were included.

RESULTS

The resection of the posterior nasal nerves with turbinoplasty significantly reduced detection and recognition thresholds on olfactory testing. The rhinorrhoea severity, detection threshold and recognition threshold were significantly lower after resection of the posterior nasal nerves with turbinoplasty than after turbinoplasty alone, although there were no significant differences between the two groups before surgery.

CONCLUSION

This is the first study to show that the resection of the peripheral branches of the posterior nasal nerves in the inferior turbinate with turbinoplasty more effectively inhibits allergic symptoms compared with turbinoplasty alone. It also showed that the resection of the peripheral branches of the posterior nasal nerves can inhibit olfactory dysfunction.

Cholinergic neuron-like D-U87 cells promote polarization of allergic rhinitis T-helper 2 cells

BACKGROUND

Parasympathetic nerve hypersensitivity contributes to the severity of allergic rhinitis (AR), but the precise mechanism underlying neuroimmune regulation in patients with AR remains unclear. This study investigated the effect of cholinergic nerve inhibition on AR CD4⁺ T-helper (Th)2-cell polarization and the underlying regulatory mechanism in vitro.

METHODS

An in-vitro neuroimmune coculture model of D-U87 cells and CD4⁺ T cells was established. D-U87 cells with cholinergic neuron characteristics were used as cholinergic neuron models. CD4⁺ T cells were derived from peripheral blood monocytes from AR patients (n = 60) and control subjects (n = 40). Th1- and Th2-cell percentages were measured by flow cytometry. Proteins involved in related signaling pathways were analyzed by protein chip assay and Western blotting.

RESULTS

The Th2-cell percentage among CD4⁺ T cells from AR patients was significantly increased after coculture with D-U87 cells and was decreased by ipratropium bromide (IB) treatment. In contrast, the Th1-cell percentage among control CD4⁺ T cells was significantly increased after coculture with D-U87 cells, but was unaltered by IB treatment. Furthermore, phosphorylated Akt (p-Akt) protein levels increased in CD4⁺ T cells from both controls and AR patients after coculture with D-U87 cells and decreased after IB treatment. However, higher p-Akt levels were observed in cells from AR patients than in cells from control subjects. Moreover, Akt inhibition decreased Th2-cell percentage in AR patients.

CONCLUSION

In-vitro cholinergic nerve inhibition with IB decreased AR CD4⁺ T-cell polarization into Th2 cells partially through an Akt-dependent mechanism.

Development of a rat model of patulous eustachian tube by mandibular nerve resection

OBJECTIVE

Patulous eustachian tube (PET) is currently treated using a variety of conservative or surgical approaches. To further elucidate the pathology of PET and to establish new therapies, the development of an animal model is necessary. The objective of this study was to develop a highly reproducible and sustainable rat model of PET by mandibular nerve resection.

METHODS

Sixteen rats underwent mandibular nerve resection. Following an external incision, the main trunk of the mandibular nerve at the foramen ovale was identified in the pterygoid fossa, and its branches were resected. This surgery was performed on the right side, with the unoperated left side used as the control. To determine eustachian tube (ET) function, passive opening pressure (POP) was measured using inflation method up to Week 16 post-surgery. Changes in POP were statistically compared to the preoperative level on the operated and control sides. In addition, specimens of the ET and its surrounding tissue at Week 16 post-surgery were prepared for morphological evaluation in eight rats.

RESULTS

On the control side, POP did not significantly decrease across the 16 weeks post-surgery compared to the preoperative level. In contrast, on the operated side, POP was significantly decreased at Week 2 and continued to be lower than the preoperative level until at least Week 16 post-surgery. POP dropped 10% or more on the operated side examined in thirteen rats. Histologically, the medial pterygoid muscle was atrophied on the operated side mainly.

CONCLUSION

Mandibular nerve resection in rats may be an effective method for generating an animal model of PET. It was suggested that this rat model may be useful for verifying new treatments for PET.

Glycogen depletion can increase the specificity of mucin detection in airway tissues

Objective

Mucin is an important parameter for detection and assessment in studies of airway disease including asthma and cystic fibrosis. Histochemical techniques are often used to evaluate mucin in tissues sections. Periodic acid Schiff (PAS) is a common technique to detect neutral mucins in tissue, but this technique also detects other tissue components including cellular glycogen. We tested whether depletion of glycogen, a common cellular constituent, could impact the detection of mucin in the surface epithelium of the trachea.

Results

Normal tissues stained by PAS had significantly more staining than serial sections of glycogen-depleted tissue with PAS staining (i.e. dPAS technique) based on both quantitative analysis and semiquantitative scores. Most of the excess stain by the PAS technique was detected in ciliated cells adjacent to goblet cells. We also compared normal tissues using the Alcian blue technique, which does not have reported glycogen staining, with the dPAS technique. These groups had similar amounts of staining consistent with a high degree of mucin specificity. Our results suggest that when using PAS techniques to stain airways, the dPAS approach is preferred as it enhances the specificity for airway mucin.

Catgut Implantation at Acupoint Reduces Immune Reaction in a Rat Model of Allergic Rhinitis

Allergic rhinitis (AR), an IgE-mediated response, is characterized by a Th2-type immunological pattern together with mast cells activation. Acupuncture, with the use of implanted catgut, is a traditional therapy that has been widely applied for the treatment of AR. However, the exact mechanism of the immunomodulatory effects of catgut implantation at acupoint (CIAA) remains unclear, in part due to the lack of a suitable laboratory animal model. We developed and optimized a rat model of ovalbumin- (OVA-) induced allergic inflammation, characterized by increased IL-4, sIgE, and SP and reciprocal decrease of IFN-γ. In the present study, we have further used this model to address the immunomodulatory effects of CIAA stimulation at Yingxiang (LI20) and Zusanli (ST36) acupoints and to elucidate the mechanisms involved in the regulation of SP, sIgE, IL-4, IFN-γ, TLR2, and TLR4. After AR model was established via OVA challenge, the rats were randomized as follows: control, model, sham-operated, 1-week CIAA (C1), 2-week CIAA (C2), and Budesonide nasal spray. The C1 and C2 groups were subjected to the bilateral acupoint Yingxiang (LI20) and Zusanli (ST36), respectively. Multiple analyses and quantifications were performed, which revealed that due to the persistent stimulus to acupoints by embedding catgut, the C2 group improved AR symptoms, compared to the C1 group. We conclude that CIAA at the Yingxiang (LI20) and Zusanli (ST36) acupoints effectively reduces allergic symptoms and inflammatory parameters in the rat model of AR. Thus, CIAA treatment is potentially an alternative therapeutic modality in AR.

Autonomic nervous system dysfunction and sinonasal symptoms

Background

The autonomic nervous system (ANS) richly innervates the nose and paranasal sinuses, and has a significant role in lower airway diseases, e.g., asthma. Nonetheless, its contribution to sinonasal symptoms is poorly understood. This review aimed to explore the complex relationship between the ANS and sinonasal symptoms, with reference to systemic diseases and triggers of ANS dysfunction.

Methods

A review of articles published in English was conducted by searching medical literature databases with the key words “autonomic nervous system” and (“sinusitis” or “nose” or “otolaryngology”). All identified abstracts were reviewed, and, from these, relevant published whole articles were selected.

Results

The ANS has a significant role in the pathophysiologic mechanisms that produce sinonasal symptoms. There was limited evidence that describes the relationship of the ANS in sinonasal disease with systemic conditions, e.g. hypertension. There was some evidence to support mechanisms related to physical and psychological stressors in this relationship.

Conclusion

The role of ANS dysfunction in sinonasal disease is highly complex. The ANS sits within a web of multiple factors, including personality and psychological distress, that contribute to sinonasal symptoms. Further research will help to clarify the etiology of ANS dysfunction and its contribution to common systemic conditions.

Neuroendocrine cells derived chemokine vasoactive intestinal polypeptide (VIP) in allergic diseases

Worldwide increase incidences of allergic diseases have heightened the interest of clinicians and researchers to understand the role of neuroendocrine cells in the recruitment and activation of inflammatory cells. Several pieces of evidence revealed the association of neuropeptides in the pathogenesis of allergic diseases. Importantly, one such peptide that is secreted by neuronal cells and immune cells exerts a wide spectrum of immunological functions as cytokine/chemokine is termed as Vasoactive Intestinal Peptide (VIP). VIP mediates immunological function through interaction with specific receptors namely VPAC-1, VPAC-2, CRTH2 and PAC1 that are expressed on several immune cells such as eosinophils, mast cells, neutrophils, and lymphocytes; therefore, provide the basis for the action of VIP on the immune system. Additionally, VIP mediated action varies according to target organ depending upon the presence of specific VIP associated receptor, involved immune cells and the microenvironment of the organ. Herein, we present an integrative review of the current understanding on the role of VIP and associated receptors in allergic diseases, the presence of VIP receptors on various immune cells with particular emphasis on the role of VIP in the pathogenesis of allergic diseases such as asthma, allergic rhinitis, and atopic dermatitis. Being crucial signal molecule of the neuroendocrine-immune network, the development of stable VIP analogue and/or antagonist may provide the future therapeutic drug alternative for the better treatment of these allergic diseases. Taken together, our current review summarizes the current understandings of VIP biology and further explore the significance of neuroendocrine cells derived VIP in the recruitment of inflammatory cells in allergic diseases that may be helpful to the investigators for planning the experiments and accordingly predicting new therapeutic strategies for combating allergic diseases. Summarized graphical abstract will help the readers to understand the significance of VIP in allergic diseases.

Concentration-dependent effects of PM2.5 mass on expressions of adhesion molecules and inflammatory cytokines in nasal mucosa of rats with allergic rhinitis

Allergic rhinitis (AR) represents a clinical health issue affecting approximately 500 million people worldwide. This study aimed to explore the effects of airborne fine particulate matter (PM_2.5) on the nasal mucosa of rats with AR. Seventy-five healthy male SD rats were included and randomly divided into the normal, model, low-concentration, middle-concentration, and high-concentration groups (15 rats each group). AR rat models were established using sensitized mixture and were stimulated using different concentrations of PM_2.5. Sneeze and nose-scratching events were observed. Automatic hematology analyzer was utilized to count white blood cells (WBCs). The serum IgE, ICAM-1, and VCAM-1 expressions, eosinophil (EOS) infiltration, and IFN-γ, IL-4, IL-5, IL-33, and TSLP expressions were detected by ELISA, HE staining, and qRT-PCR. Greater numbers of WBCs, increased IgE level, elevated levels of ICAM-1, VCAM-1, EOS, IFN-γ, IL-4, IL-5, IL-33, and TSLP in the model, low-concentration, middle-concentration, and high-concentration groups than the normal group. The same trend also exhibited in rats of the middle-concentration and high-concentration groups than that of the model and low-concentration groups. Comparisons between normal rats and AR rats indicated that AR rats exhibit remarkably higher cytokine expression levels of IFN-γ, IL-4, IL-5, TSLP, and IL-33. The study revealed that as stimulation is triggered by PM_2.5, AR rats result in increased levels of adhesion molecules and inflammatory cytokine expressions in a concentration-dependent manner. Analyses of PM_2.5 as well as, its effects on AR are crucial in the continued drive for both prevention and management of the disease.