CpG oligodeoxynucleotides enhance airway epithelial barrier integrity

Decoding the role of DNA methylation in allergic diseases: from pathogenesis to therapy

Allergic diseases, characterized by a broad spectrum of clinical manifestations and symptoms, encompass a significant category of IgE-mediated atopic disorders, including asthma, allergic rhinitis, atopic dermatitis, and food allergies. These complex conditions arise from the intricate interplay between genetic and environmental factors and are known to contribute to socioeconomic burdens globally. Recent advancements in the study of allergic diseases have illuminated the crucial role of DNA methylation (DNAm) in their pathogenesis. This review explores the factors influencing DNAm in allergic diseases and delves into their mechanisms, offering valuable perspectives for clinicians. Understanding these epigenetic modifications aims to lay the groundwork for improved early prevention strategies. Moreover, our analysis of DNAm mechanisms in these conditions seeks to enhance diagnostic and therapeutic approaches, paving the way for more effective management of allergic diseases in the future.

Role of airway epithelial barrier dysfunction in pathogenesis of asthma

Bronchial asthma is characterized by persistent cough, increased sputum, and repeated wheezing. The pathophysiology underlying these symptoms is the hyper-responsiveness of the airway along with chronic airway inflammation. Repeated injury, repair, and regeneration of the airway epithelium following exposure to environmental factors and inflammation results in histological changes and functional abnormalities in the airway mucosal epithelium; such changes are believed to have a significant association with the pathophysiology of asthma. Damage to the barrier functions of the airway epithelium enhances mucosal permeability of foreign substances in the airway epithelium of patients with asthma. Thus, epithelial barrier fragility is closely involved in releasing epithelial cytokines (e.g., TSLP, IL-25, and IL-33) because of the activation of airway epithelial cells, dendritic cells, and innate group 2 innate lymphoid cells (ILC2). Functional abnormalities of the airway epithelial cells along with the activation of dendritic cells, Th2 cells, and ILC2 form a single immunopathological unit that is considered to cause allergic airway inflammation. Here we use the latest published literature to discuss the potential pathological mechanisms regarding the onset and progressive severity of asthma with regard to the disruption of the airway epithelial function.