Locally Delivered RNA Therapeutics for Regulating Chronic Epithelial Dysfunction of the Upper Airway

Abstract

Chronic epithelial dysfunction of the upper airway is a cornerstone in the pathogenesis of various respiratory disorders, including chronic rhinosinusitis, allergic rhinitis, and certain forms of asthma. Recent advances in RNA-based therapeutics, particularly those delivered locally, have opened promising avenues for targeted molecular intervention. This review synthesizes the latest evidence on the epidemiology, pathophysiology, clinical features, diagnosis, and management of chronic epithelial dysfunction, placing special emphasis on the clinical translation and future potential of locally administered RNA therapeutics. The review aims to provide healthcare professionals with actionable insights into mechanism-based treatment strategies and guideline-aligned care, while highlighting recent technological and pharmacological innovations in the field.

Introduction

Chronic epithelial dysfunction of the upper airway represents a complex interplay between genetic predisposition, environmental exposure, and aberrant immune responses, leading to persistent inflammation and tissue remodeling. Traditionally managed with systemic and topical pharmaceuticals, these conditions often exhibit suboptimal response rates and are associated with high morbidity. The emergence of RNA therapeutics, particularly those designed for local delivery, has ushered in a new era of precision medicine, allowing for the modulation of disease pathways at the transcriptomic level. This article provides a comprehensive overview of the clinical landscape, with a focus on the role of locally delivered RNA-based therapies for upper airway diseases.

Epidemiology / Disease Burden

Chronic upper airway diseases characterized by epithelial dysfunction, such as chronic rhinosinusitis (CRS) and allergic rhinitis (AR), affect a significant proportion of the global population. CRS alone has a prevalence of approximately 10-12% in Western populations, while AR affects up to 30% of adults and 40% of children. These conditions contribute substantially to healthcare utilization, economic burden, and impairment in quality of life. Moreover, they frequently coexist with lower airway diseases, compounding morbidity and complicating management strategies. Epidemiological studies have consistently identified the persistence of epithelial barrier dysfunction as a predictive marker for disease severity and recurrence.

Pathophysiology

The pathophysiology of chronic epithelial dysfunction in the upper airway is multifactorial. Disruption of the mucosal barrier leads to increased permeability, facilitating the ingress of allergens, pathogens, and pollutants. This triggers innate and adaptive immune responses, characterized by the release of pro-inflammatory mediators, recruitment of eosinophils and neutrophils, and subsequent tissue remodeling. Dysregulation of genes responsible for tight junction proteins, mucin production, and antimicrobial peptide expression has been implicated. RNA therapeutics, including small interfering RNAs (siRNAs) and antisense oligonucleotides (ASOs), offer the potential to silence or modulate these pathogenic gene expressions, thereby restoring epithelial integrity and attenuating inflammation.

Risk Factors

Key risk factors for chronic epithelial dysfunction include genetic susceptibility, recurrent viral or bacterial infections, environmental allergen exposure, air pollution, smoking, and occupational hazards. Polymorphisms in genes associated with epithelial junctions and immune regulation increase vulnerability. Additionally, comorbid conditions such as asthma and atopic dermatitis are linked to heightened risk and more refractory disease courses. Identification of these risk factors is crucial for early intervention and targeted preventive strategies.

Clinical Features

Patients commonly present with persistent nasal congestion, mucopurulent discharge, facial pain or pressure, anosmia, and cough. In more severe cases, there may be evidence of polyp formation, chronic mucosal thickening, and lower respiratory tract involvement. Non-specific symptoms such as fatigue and sleep disturbance are prevalent and contribute to diminished quality of life. Objective findings may include endoscopic evidence of mucosal edema, ulceration, and altered mucociliary clearance.

Diagnosis

Diagnosis is based on a combination of clinical assessment, nasal endoscopy, and radiological imaging (typically CT scan of the paranasal sinuses). Functional assessment of epithelial integrity can be performed using various biomarkers, including nasal nitric oxide, exhaled breath condensate analysis, and immunohistochemical staining for tight junction proteins. Molecular profiling is increasingly utilized to identify specific gene expression signatures amenable to RNA-based intervention. Differential diagnosis includes infectious, neoplastic, and autoimmune etiologies, necessitating a thorough workup in persistent or atypical cases.

Treatment & Management

Conventional treatment approaches include intranasal corticosteroids, saline irrigation, antihistamines, and, in selected cases, systemic corticosteroids or antibiotics. Surgical intervention may be warranted for refractory cases or in the presence of obstructive polyposis. However, these modalities often fail to address the underlying molecular drivers of epithelial dysfunction, leading to recurrence and chronicity. There is a growing need for therapies that can specifically target the pathobiological underpinnings of disease at the molecular level.

Recent Advances / Emerging Therapies

Locally delivered RNA therapeutics have emerged as a transformative strategy for upper airway disease. siRNAs and ASOs can be formulated for intranasal or topical application, achieving high local concentrations while minimizing systemic exposure and adverse effects. Preclinical studies have demonstrated the efficacy of siRNAs targeting pro-inflammatory cytokines (e.g., IL-4, IL-5, IL-13), mucin genes (MUC5AC, MUC5B), and epithelial barrier proteins (occludin, claudins) in restoring barrier function and reducing inflammation. Early-phase clinical trials show promising results, with significant reductions in symptom burden and mucosal inflammation. Challenges remain regarding delivery vehicles, stability, and off-target effects, but advances in nanoparticle-based carriers and chemical modifications are rapidly addressing these hurdles.

Guideline Recommendations

While current guidelines for chronic upper airway diseases emphasize established pharmacologic and surgical therapies, there is increasing recognition of the role of molecularly targeted treatments. Expert consensus encourages the integration of emerging RNA-based therapeutics into clinical trial frameworks and recommends molecular profiling for patients with refractory or atypical disease. Ongoing multicenter studies are likely to inform future updates and may lead to the routine adoption of locally delivered RNA therapies in specialized care settings.

Conclusion

Locally delivered RNA therapeutics represent a paradigm shift in the management of chronic epithelial dysfunction in the upper airway. By directly targeting pathogenic molecular pathways, these therapies hold promise for improved disease control, reduced recurrence, and enhanced patient outcomes. Continued translational research, alongside rigorous clinical evaluation and guideline development, will be essential to realize the full potential of these innovative interventions in routine practice.