Therapeutic effects of intranasal cyclosporine for eosinophilic rhinosinusitis with nasal polyps in a mouse model

Which are the best murine models to study Eosinophilic Chronic Rhinosinusitis? A contemporary review

OBJECTIVE

Mechanisms that lead to Eosinophilic Chronic Rhinosinusitis (ECRS) are not fully established in the literature. It is desirable to assess ECRS in a model that embraces most of the related events. This article reviewed the murine models for ECRS and compared them regarding eosinophilic polypoid formation.

METHODS

The authors reviewed the articles that included the terms "chronic rhinosinusitis" OR "chronic sinusitis" AND "animal model". We analyzed articles in English that evaluated both the number of polyps and the number of eosinophils in the sinus mucosa of mouse models.

RESULTS

We identified a total of 15 articles describing different models of ECRS that used BALB/c or C57BL/6 mice, and different triggers/stimulants such as Staphylococcus aureus Enterotoxin B (SEB) + Ovalbumin (OVA); House Dust Mite (HDM) ± Ovalbumin (OVA); and Aspergillus oryzae Protease (AP) + Ovalbumin (OVA). OVA associated with SEB was the commonest protocol to induce ECRS in both BALB/c and C57BL/6 mice, and it produced a robust response of eosinophilic nasal polyps in both. AP + OVA protocol also led to a good ECRS response. The other models were not considered adequate to produce eosinophilic polyps in mice.

CONCLUSION

In conclusion, OVA associated with SEB seems to produce the most robust eosinophilic sinonasal inflammation.

Murine model for chronic rhinosinusitis: an interventional study

BACKGROUND

Chronic rhinosinusitis (CRS) is a complex inflammatory disease of the sinonasal tract. To understand this disease entity and develop targeted treatments, a reproducible animal model is paramount.

AIMS/OBJECTIVES

To optimize a murine model of eosinophilic CRS by establishing benchmark histological markers and validate its fidelity in evaluating intranasal treatments.

MATERIAL AND METHODS

Forty-five Balb/c mice were included in the 7-week protocol. Experimental animals (n = 20) were induced a CRS disease state upon receiving intraperitoneal sensitization with ovalbumin (OVA), followed by intranasal OVA with Aspergillus oryzae protease. Analysis of complete blood count with differential, peripheral blood smear, and histological markers from the nasal cavity mucosa were performed. CRS mice were additionally treated with intranasal saline (n = 5) or mometasone (n = 10) and compared with control groups of untreated CRS (n = 5) and healthy (n = 5) mice after week 7.

RESULTS

Histological analysis of experimental animal nasal mucosa revealed significantly higher levels of eosinophilic tissue infiltration/degranulation, hyaline droplets, Charcot-Leyden crystals, and respiratory epithelial thickness compared to healthy controls. Treatment with mometasone significantly reversed the histopathological changes observed in CRS mice.

CONCLUSION AND SIGNIFICANCE

This murine model induced substantial local eosinophilic inflammation within sinonasal mucosa, that was reversible with mometasone. This model may be used to evaluate the efficacy of therapeutics designed to target CRS.

The Efficacy of Functional Endoscopic Sinus Surgery Combined With Triamcinolone Acetonide Aqueous Nasal Spray for the Treatment of Chronic Rhinosinusitis

Objective

We aimed to investigate the efficacy of functional endoscopic sinus surgery (FESS) combined with triamcinolone acetonide aqueous nasal spray (TAA AQ) for the treatment of chronic rhinosinusitis.

Methods

From December 2019 to June 2021, 109 patients with chronic rhinosinusitis were classified into a control group (n = 50) and an experimental group (n = 59) according to the method of treatment. Subjects in the control group were treated with FESS while those in the experimental group were treated with FESS + TAA AQ. We then compared clinical indices, total effective rate, and the clinical symptoms of patients between the two groups. The pre- and postoperative serum levels of inflammatory cytokines were also determined. Before and 12 months after surgery, we analyzed the recovery of the nasal mucosa, olfactory function, and mucociliary transport rate of each patient. Postoperative complications were observed and recorded and the quality-of-life 12 months after surgery was ascertained.

Results

Clinical indices and total effective rate were higher in the experimental group. After treatment, the VAS score and serum levels of inflammatory cytokines in the two groups both decreased, although the experimental group had lower VAS scores and inflammatory cytokine levels. Six months after treatment, olfactory function, and the recovery of nasal mucosa were improved, MTR had increased, and the total incidence of complications had reduced in the experimental group when compared with the control group. No significant difference was found between the two groups in terms of quality-of-life (P > 0.05).

Conclusion

The combination of FESS and TAA AQ exerted a certain therapeutic effect on chronic rhinosinusitis.

Activation of STAT6 by intranasal allergens correlated with the development of eosinophilic chronic rhinosinusitis in a mouse model

Eosinophilic chronic rhinosinusitis (ECRS) is a chronic inflammatory disease characterized by prominent eosinophilic infiltration along with a T-helper-2 (Th2) response. It has been well documented that signal transducer and activator of transcription 6 (STAT6) is a nuclear transcription factor that mediates Th2-type immunity and is implicatory of STAT1 and STAT3 in the pathogenesis of allergic airway diseases. However, little is known about the association between STATs and ECRS. Here, we explored the relationship between STAT1, STAT3, and/or STAT6 and eosinophilic inflammation accompanied by Th2-type immunity in a mouse model of ECRS. An ovalbumin (OVA)-staphylococcal enterotoxin B (SEB)-induced ECRS murine model was first established. The mucosal histological alterations were determined using hematoxylin and eosin staining. The number of eosinophils in peripheral blood was measured using a blood cell analyzer. The cytokine (IL-4, IL-5, IL17 A and IFN-γ) expression levels in the sinonasal mucosa and total and OVA-specific IgE from serum were measured using ELISA. Then, the protein levels of STAT1, STAT3, STAT6, phosphorylated STAT1 (p-STAT1), p-STAT3, p-STAT6, T-box expressed in T-cells (T-bet), GATA binding protein 3 (GATA-3), and retinoic acid receptor-related orphan receptor γ (RORγt) in the sinonasal mucosa were examined by immunohistochemical staining or Western blotting. Local administration of OVA combined with SEB (OVA + SEB) induced multiple polyp-like lesions, accompanied by prominent eosinophilic infiltration in the sinonasal mucosa. The OVA- and OVA+SEB-treated groups showed significantly higher eosinophil counts from peripheral blood and total and OVA-specific IgE levels from serum than those in the PBS- and SEB-treated groups. The levels of p-STAT6 were markedly increased by OVA + SEB exposure, as well as GATA-3, IL-4, and IL-5, but did not affect STAT6, p-STAT1, p-STAT3, T-bet, RORγt, IFN-γ, or IL-17A. Furthermore, an eosinophil count in the sinonasal mucosa showed a positive correlation with the level of p-STAT6 in the ECRS mouse model. Signal transducer and activator of transcription 6 signaling could be activated in the OVA+SEB-induced ECRS model and might be a crucial signal transducer in the development of Th2-skewed ECRS.

Comparison of viral RNA-host protein interactomes across pathogenic RNA viruses informs rapid antiviral drug discovery for SARS-CoV-2

In contrast to the extensive research about viral protein-host protein interactions that has revealed major insights about how RNA viruses engage with host cells during infection, few studies have examined interactions between host factors and viral RNAs (vRNAs). Here, we profiled vRNA-host protein interactomes for three RNA virus pathogens (SARS-CoV-2, Zika, and Ebola viruses) using ChIRP-MS. Comparative interactome analyses discovered both common and virus-specific host responses and vRNA-associated proteins that variously promote or restrict viral infection. In particular, SARS-CoV-2 binds and hijacks the host factor IGF2BP1 to stabilize vRNA and augment viral translation. Our interactome-informed drug repurposing efforts identified several FDA-approved drugs (e.g., Cepharanthine) as broad-spectrum antivirals in cells and hACE2 transgenic mice. A co-treatment comprising Cepharanthine and Trifluoperazine was highly potent against the newly emerged SARS-CoV-2 B.1.351 variant. Thus, our study illustrates the scientific and medical discovery utility of adopting a comparative vRNA-host protein interactome perspective.

The Effect of Triamcinolone-Soaked Gelfoam in Patients with Polypoid Mucosal Change after Endoscopic Sinus Surgery

Background and Objectives: Chronic rhinosinusitis with nasal polyps (CRSwNP) recurs frequently after endoscopic sinus surgery (ESS). The aim of study was to evaluate the efficacy of triamcinolone-soaked absorbable gelatin foam (gelfoam) as a treatment for recurred polypoid changes after ESS.Subjects and Method: A total of 35 patients and 57 nasal cavities was retrospectively reviewed. All patients underwent triamcinolone- infused gelfoam packing for 1 week under nasal endoscopic guidance. Endoscopic scores were evaluated at 1 week, 1 month, and 3 months. We analyzed clinical characteristics between success and failure groups.Results: Endoscopic scores were significantly improved after triamcinolone-soaked gelfoam packing, and the effects were maintained at 3-month follow-up (1.85±0.61 vs. 0.82±0.77, p＜0.001). Duration between surgery and gelfoam packing was shorter in the success group compared to the failure group (8.2±6.9 vs. 13.7±8.4 weeks, p=0.033). Serum eosinophil cationic protein and tissue eosinophil counts were significantly higher in the failure group (p=0.025 and p=0.010, respectively).Conclusion: Triamcinolone-soaked gelfoam packing is an effective and safe method for managing recurrent polypoid change in patients with CRSwNP after ESS. Early intervention contributed to a successful result, and eosinophilic inflammation was associated with poor outcomes.

Models for the study of nasal and sinus physiology in health and disease: A review of the literature

Objective

Chronic sinusitis is a very common yet poorly understood medical condition with significant morbidity. Hence, it remains an entity that is difficult to treat with unsatisfactory outcomes of current management options. This necessitates research into the etiology and pathophysiology of the condition to enhance our knowledge and the therapeutic options. Unfortunately, this kind of research is not always feasible on human subjects due to practical and ethical limitations. Therefore, an alternative model that simulates the disease had to be found in order to overcome these limitations. These models could either be in vivo or in vitro. The aim of our review is to summarize the research findings and key discoveries of both in vivo and in vitro models of chronic sinusitis that have enhanced our understanding of the condition today and have paved the way for the future research of tomorrow.

Data Sources: PubMed literature review.

Methods

A review of the literature was conducted to identify the main successful in vivo and in vitro models for chronic sinusitis.

Results

Creating a successful model for chronic sinusitis is no easy task. Over the years, both in vivo animal models and in vitro tissue culture models were proposed, with each model having its accolades and pitfalls, with the ideal model remaining elusive to this day. However, advancing three‐dimensional cell culturing techniques seems to be a promising new way to find a more accurate model.

Conclusion

None of the current models is perfect for a thorough study of chronic sinusitis. However, three‐dimensional cell cultures have the potential to bridge the gap between in vivo and in vitro studies.

Level of Evidence

NA

Animal Models in CRS and Pathophysiologic Insights Gained: A Systematic Review

OBJECTIVE

Chronic rhinosinusitis (CRS) is a multifactorial inflammatory disease. In particular, CRS with eosinophilic features and/or nasal polyps (NPs) is often recalcitrant to current treatment; thus, appropriate animal models are mandatory to elucidate the pathogenesis of CRS and develop novel and efficient treatment modalities. The author reviewed the recently proposed animal models in CRS and discussed the pathophysiologic insights gained. Data Sources: Articles in the English language referenced in MEDLINE/PubMed from the year 2006 onward (for last 10 years). Review Methods: Review of the literature regarding animal models and related pathologic insights in CRS.

RESULTS

Mouse, rabbit, and sheep models of CRS have been used for studying the pathogenesis of CRS. Most of researchers adopted animal models of CRS to prove any molecular mechanisms or therapeutic efficacy. In vitro or human findings and related hypothesis were evaluated in vivo using these models. In addition, novel therapeutic candidates for CRS with or without NP have been applied to animal models.

CONCLUSION

Animal models have elicited insights into the pathogenesis of CRS and also have been useful in testing new treatment modalities. Although there are still clear limitations in the animal studies, newly proposed or revised animal models would be helpful to understand the exact pathophysiology of CRS.

Prolonged allergen exposure is associated with increased thymic stromal lymphopoietin expression and Th2-skewing in mouse models of chronic rhinosinusitis

OBJECTIVES/HYPOTHESIS

Chronic rhinosinusitis (CRS) is characterized by a dysfunctional host-environment interaction at the nasal mucosa. Contributions of host susceptibility factors such as atopy and aspirin sensitivity to CRS pathophysiology are well established. However, clinical studies on the effects of environmental factors are limited. This study investigates the histological and immunological effects of allergen exposure duration in animal models.

STUDY DESIGN

Animal study.

METHODS

A murine model for CRS with nasal polypoid lesions was induced by instilling ovalbumin/staphylococcal enterotoxin B (SEB) into murine nasal cavities for 12 (short term) or 24 weeks (long term). Histopathological changes were observed. Interleukin (IL)-4, IL-17A, IL-10, and interferon (INF)-γ levels from nasal lavage fluid were measured using enzyme-linked immunosorbent assay. Gene expressions of IL-25, thymic stromal lymphopoietin (TSLP), IL-4, IL-5, INF-γ, C-C motif chemokine ligand (CCL)-11, CCL-24, C-X-C motif chemokine ligand (CXCL)-1, CXCL-2, intercellular adhesion molecule 1, vascular cell adhesion molecule 1, matrix metallopeptidase (MMP)-7, and tissue inhibitor of metalloproteinase (TIMP)-3 were analyzed from the nasal mucosa.

RESULTS

Long-term CRS models exhibited increased polypoid lesions, edematous mucosal thickness, and eosinophil infiltration compared with short-term models and showed a higher IL-10 level but lower IFN-γ and IL-17A protein levels. Moreover, CCL-24 and MMP-7 gene expressions increased whereas TIMP-3 expression decreased in long-term models compared to controls and short-term models. IL-25 and TSLP expressions were upregulated at mRNA and protein levels in short-term and long-term CRS models, respectively. Furthermore, TSLP mRNA expression was positively associated with IL-5 (r = 0.8754) and inversely correlated to IFN-γ (r = -0.7212) in CRS models.

CONCLUSIONS

Prolonged allergen exposure in ovalbumin/SEB-induced CRS models maintains Th2 inflammation and reduces Th1 inflammation, which was associated with upregulation of TSLP.

LEVEL OF EVIDENCE

NA Laryngoscope, 126:E265-E272, 2016.

Pathogenesis of eosinophilic chronic rhinosinusitis

Eosinophilic chronic rhinosinusitis (ECRS) is considered a refractory and intractable disease. Patients with ECRS present with thick mucus production, long-term nasal congestion, loss of sense of smell, and intermittent acute exacerbations secondary to bacterial infections. Despite medical and surgical interventions, there is a high rate of recurrence with significant impairment to quality of life. The recent increasing prevalence of ECRS in south Asian countries and the strong tendency of ECRS to reoccur after surgery should be considered. The majority of cases need repeat surgery, and histological examinations of these cases show eosinophilic-dominant inflammation. The degradation and accumulation of eosinophils, release of cytokines, and mucus secretion have important roles in the pathogenesis of ECRS. ECRS differs from non-ECRS, in which eosinophils are not involved in the pathogenesis of the disease, and also in terms of many clinical characteristics, blood examination and nasal polyp histological findings, clinical features of the disease after surgery, efficacy of medications, and computed tomography findings. This review describes the clinical course, diagnosis, and treatment of ECRS as well as its pathophysiology and the role of eosinophils, mucus, cytokines, and other mediators in the pathogenesis of ECRS.