Background: Allergic rhinitis (AR) is an allergic disease of nasal mucosa. LncRNAs are key modulators affecting AR development. Neverthelss, the impact of lncRNA ANRIL in AR is not clear.
Objective: This work decided to study the mechanism underlying the impact of ANRIL on TLR4 expression through targeting miR-16-5p during autophagy and epithelial barrier dysfunction in the progression of AR.
Methods: Human nasal epithelial cells were exposed to TNF-α to establish AR cell model, AR mice model was constructed by ovalbumin (OVA) treatment. QRT-PCR or western blot assays were applied to measure the levels of mRNA and proteins. Dual-luciferase reporter gene detection and RIP assay were conducted to verify the association between ANRIL and miR-16-5p. Autophagy flux assessment by mRFP-GFP-LC3 method was performed to detect autophagy level.
Results: AR progression could induce the autophagy, and the expressions of tight junction proteins were downregulated in AR cell model. Moreover, knockdown of ANRIL reversed the effect of AR on autophagy-related protein and tight junction proteins MiR-16-5p was found to be bound with ANRIL and miR-16-5p inhibitor could reverse ANRIL knockdown-induced downregulation of autophagy-related proteins and epithelial barrier dysfunction. In addition, miR-16-5p directly targeted TLR4. Furthermore, knockdown of ANRIL reversed miR-16-5p and TLR4 expression, autophagy level, and tight junction protein levels in nasal mucosa of AR mice.
Conclusion: This study illustrated that ANRIL acted as a promotion factor in AR induced autophagy and epithelial barrier dysfunction by enhancing the expression of TLR4 via interacting with miR-16-5p.
Keywords: ANRIL; LncRNAs; TLR4; allergic rhinitis; miR-16-5p.