Nonylphenol Exacerbates Allergic Rhinitis in Vitro and Mice

Description

In previous studies, we verified that nonylphenols (NPs) facilitate the occurrence of allergic rhinitis (AR). By analyzing data from the Gene Expression Omnibus database and subsequent verification with clinical samples, we confirmed that the A3SS alternative splicing of TRAF2 and NCK-interacting kinase (TNIK) plays a significant role in AR. Meanwhile, we discovered that NP could suppress the expression of hnRNPUL1 and increase the alternative splicing ratio of TNIK in the nasal mucosa of mice. Further studies revealed that downregulation of the splicing factor hnRNPUL1 promoted A3SS alternative splicing in TNIK, leading to the deposition of β-catenin in nasal mucosa tissue and enhanced binding of β-catenin with TCF1 and TCF4. This binding, in turn, increased the cell ratio of Th2 cells, decreased the ratio of Th1 and Treg cells, and shifted the Th1/Th2 ratio in favor of Th2, driving the immune response toward Th2 cell proliferation and differentiation. A mere increase in β-catenin expression sufficiently promoted promotes general proliferation but does not drive subset differentiation. Under NP intervention, the expression of hnRNPUL1 was reduced, Th2 proliferation and differentiation in local tissues were more pronounced, and symptoms in mice were more severe than under non-NP intervention. These findings confirm that NP intake can interfere with the transcription process and exacerbate the development of AR.

Steps to reproduce

1 Clinical Samples nasal exfoliated cells from 77 AR patients and 16 controls, plus mucosal tissues from 9 AR and 5 non-AR patients, were collected and stored at –80°C. AR was diagnosed clinically and via IgE testing. No corticosteroids were used 4 weeks prior. Ethics approval was obtained. Patient details are in Table 1. 2 Murine Model 30 female C57BL/6 mice were grouped into control, OVA, and NP+OVA. AR was induced with OVA/alum injections and nasal challenges. NP group received 5 µg/kg/day NP via gavage. Symptoms were scored after final challenge. Approved by animal ethics committee. 3 Histopathology Nasal tissues were fixed, decalcified, sectioned, and HE-stained for morphological analysis. 4 Cell Culture and Transfection HNEpCs were cultured per standard protocols. Transfection with β-catenin plasmid or hnRNPUL1 siRNA was performed using jetPRIME. 5 RNA Detection RNA was extracted, reverse transcribed, and quantified via qPCR with GAPDH as reference. 6 Immunoblotting Proteins were blotted with antibodies against hnRNPUL1, β-catenin, TCFs, T-bet, GATA-3, Foxp3, and GAPDH, then visualized and quantified. 7 Immunoprecipitation Lysates were incubated with anti-β-catenin and beads, followed by washing and immunoblotting. 8 PBMC Co-culture PBMCs from human blood were activated and co-cultured with transfected HNEpCs for 5 days. 9 Flow Cytometry Cells were stained for CD4, IFN-γ, IL-4, CD25, and Foxp3 to identify Th1, Th2, and Treg subsets. 10 Statistical Analysis RNA-seq data were analyzed for DEGs and AS events. Functional enrichment and statistical comparisons were performed with appropriate tests. Significance was set at p<0.05

Institutions

• Shengjing Hospital of China Medical University

Categories

Funders

• Science and technology plan projects of Liaoning Province

  Grant ID: 2023JH2/20200079
• Science and technology plan projects of Liaoning Province

  Grant ID: 2023JH6/100100011
• Natural Science Foundation of Liaoning Province

  Grant ID: 2024-MS-061

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