ABSTRACT
BACKGROUND: This study aims to investigate the regulatory effect of microRNA-96-5p (miR-96-5p) in the pathophysiological process of allergic rhinitis (AR). METHODS: Nasal mucosal tissue samples were collected from AR patients and healthy controls. An in vitro AR model was established by stimulating human nasal epithelial cells (HNECs) with interleukin (IL)-13. The expressions of target genes and proteins were measured by qPCR, Western blot, or ELISA. Dual-luciferase reporter assay and pull-down assay were performed to confirm the interaction between miR-96-5p and DEP domain-containing mammalian target of rapamycin-interacting protein (DEPTOR). RESULTS: The level of miR-96-5p was increased while the expression of DEPTOR was decreased in AR patients. The expressions of proinflammatory cytokines were markedly increased and the mammalian target of rapamycin (mTOR)/NF-κB pathway was activated in HNECs following IL-13 stimulation. miR-96-5p downregulation alleviated the stimulated function by IL-13. DEPTOR was the target of miR-96-5p. Knockdown of DEPTOR reversed the function of miR-96-5p inhibitor on IL-13-stimulated HNECs. CONCLUSIONS: The current study showed that miR-96-5p and DEPTOR were aberrantly expressed in AR nasal mucosa. miR-96-5p knockdown inhibited the production of inflammatory cytokines and the activation of mTOR/NF-κB pathway via targeting DEPTOR. These findings suggested that miR-96-5p might be used as a diagnostic marker and therapeutic target for the treatment of AR.
Subject(s)
Gene Expression Regulation , Intracellular Signaling Peptides and Proteins/metabolism , MicroRNAs/genetics , NF-kappa B/metabolism , Rhinitis, Allergic/etiology , Rhinitis, Allergic/metabolism , Signal Transduction , TOR Serine-Threonine Kinases/metabolism , Cytokines/genetics , Cytokines/metabolism , Humans , Inflammation Mediators/metabolism , Nasal Mucosa/immunology , Nasal Mucosa/metabolism , Nasal Mucosa/pathology , RNA Interference , Rhinitis, Allergic/diagnosisABSTRACT
[This corrects the article on p. 2570 in vol. 12, PMID: 32655791.].
ABSTRACT
An impaired epithelial barrier is often observed in allergic rhinitis (AR), which facilitates the infiltration of allergens. The aim of this study was to investigate the role of autophagy in the impaired epithelial barrier in AR and the related signalling pathways. A human nasal epithelial cell line was treated with dust mite allergen (Derp1). Autophagy was evaluated by GFP-LC3 adenovirus transfection and measurement of autophagy-related proteins. Epithelial barrier function was evaluated by measuring tight junction protein expression, transepithelial electrical resistance, and fluorescein isothiocyanate-dextran (FD4) permeability. Next, miR-125b inhibitor, miR-125b mimics, shRNA targeting FoxP3, pcDNA3.1 expressing FoxP3, and inhibitor of C-X-C motif chemokine receptor type 4 (CXCR4) were used to investigate the roles of miR-125b, FoxP3, and CXCR4 in epithelial cell autophagy and epithelial barrier function. An in vivo AR model was generated by exposing rat nasal mucosa to an allergen. Derp1 exposure enhanced autophagy and impaired the epithelial barrier in epithelial cells. Upregulation of miR-125b expression led to enhanced autophagy and impaired epithelial barrier through inhibition of FoxP3. Derp1 exposure increased miR-125b expression by increasing the expression and activation of CXCR4, which downregulated FoxP3 expression and led to enhanced autophagy and an impaired epithelial barrier. In vivo analysis confirmed the role of the CXCR4/miR-125b/FoxP3 axis in the impaired epithelial barrier in AR. This study demonstrates that the CXCR4/miR-125b/FoxP3 axis may participate in the pathogenesis of AR by regulating autophagy in epithelial cells and dysfunction of the epithelial barrier.
ABSTRACT
Nasal epithelial cells are the first barrier against allergen infiltration in allergic rhinitis (AR), and the relationship between nasal epithelial cells and mast cell-mediated hypersensitivity remains unclear. This study aimed to investigate the possible association between allergen-challenged nasal epithelial cells (AR-HNEpC) and mast cell degranulation in AR. Our data revealed that calcium influx and degranulation were increased in AR-HNEpC-co-cultured mast cells. Expression of IL-33, a factor that binds to ST2 receptors on mast cells and regulates their degranulation, was elevated in AR-HNEpC. Blocking IL-33/ST2 pathway activated autophagy and inhibited degranulation and inflammatory factor release in mast cells. Furthermore, PI3K/mTOR was increased in IL-33-treated mast cells. Inhibition on PI3K/mTOR pathway enhanced autophagy and inhibited degranulation. Analysis using an in vivo AR model supported the above findings. In conclusion, IL-33 from epithelial cells promotes degranulation of mast cells in AR through inhibition on ST2/PI3K/mTOR-mediated autophagy, which provides a potential therapeutic target for the disease.Abbreviations: AR: allergic rhinitis; IL: interleukin; TNF-α: tumor necrosis factor-alpha; INF-γ: interferon-gamma; HNEpC: human nasal epithelial cell line; ATCC: American Type Culture Collection; C48/80: compound 48/80; 3-MA: 3-methyladenine; qPCR: quantitative PCR; AR-HNEpC: dust mite allergen-treated nasal epithelial cells; IgE: immunoglobulin E; Atg7: autophagy-related gene 7.
