Interleukin‐4‒induced posttranscriptional gene regulation of CCL26 by the RNA‐binding protein HuR in primary human nasal polyp‒derived epithelial cells

Abstract

Background: Much a ention on the pathophysiology of nasal polyp (NP) has focused on eosinophils. Interleukin (IL)-4 and eotaxin-3 (C-C motif chemokine ligand 26, or CCL26) levels have been reported to be increased in eosinophilic nasal polyps. The aim of this study was to characterize CCL26 pos ranscriptional regulation by the RNAbinding protein HuR in primary human nasal polyp-derived epithelial cells (hNPDECs) challenged with IL-4. Methods:A prospective, observational study was conducted. Nasal polyp tissues were obtained from eosinophilic (n = 12) and non-eosinophilic (n = 10) NP patients, and inferior turbinate (IT) tissues were taken from control subjects (n = 9) and cultured into hNPDECs. Expression of HuR and CCL26 were measured by immunohistochemistry, Western blot analysis, enzyme-linked immunoassay, and real-time polymerase chain reaction (PCR). The nucleocytoplasmic shu ling of HuR in hNPDECs was detected by immunofluorescence. Pos ranscriptional regulation of CCL26 by HuR was tested by ribonucleoprotein immunoprecipitation assay (RIP) and dual-luciferase reporter assay. CCL26 mRNA stabilization was measured by quatititative PCR a er treatment with actinomycin D. Student's t test and one-way analysis of variance were used.Results: Immunohistochemical data show that both HuR and CCL26 were highly expressed in NP tissues, especially eosinophilic NP tissues (p < 0.05). IL-4 stimulation increased CCL26 mRNA stability, and overexpression and knockdown of HuR affected CCL26 expression. Immunofluorescence data indicate that IL-4 altered the subcellular distribution of HuR. The RIP and dual-luciferase reporter assay results supply strong evidence for HuR binding to CCL26. Conclusion:Our results provide strong support for the hypothesis that IL-4-induced expression of CCL26 in hN-PDECs relies partly on CCL26 mRNA stabilization mediated by the interaction of HuR with CCL26 3'UTR. C 2018 ARS-AAOA, LLC.

15-Lipoxygenase 1 in nasal polyps promotes CCL26/eotaxin 3 expression through extracellular signal-regulated kinase activation

“…24 At the protein level and in contrast to the RNA data, CCL26 was previously reported throughout the epithelial layer. 41 In the present study both CCL26 mRNA and protein levels were upregulated in NEC lysates of MT tissue and NPs from patients with CRSwNP. However, consistent with the mRNA data, in ex vivo samples CCL26 was largely colocalized with CK5, confirming their mRNA association at the protein level.…”

Correlation of Bromodomain Protein BRD4 Expression With Epithelial–Mesenchymal Transition and Disease Severity in Chronic Rhinosinusitis With Nasal Polyps

“…For the investigation of BRD4, E-cadherin, vimentin, and Snai1 mRNA expression from primary hNPDECs and primary human nasal epithelial cells (hNECs) cultures, fresh endonasal tissues were utilized. Primary hNPDECs were collected by gently scraping the epithelial surface of the NP tissues with a convex surgical blade and cultured as described in a previous study (25). In brief, disassociated epithelial cells were first transferred to the 50-mL conical tube and then centrifuged at 200 g for 5 min and resuspended in the bronchial epithelial cell growth medium (Lonza, Basel, Switzerland).…”

Unraveling the Role of Epithelial Cells in the Development of Chronic Rhinosinusitis

“…The release of CCL24 and CCL26 by AECs is stimulated by epithelial differentiation in response to Th2 cytokines [ 161 ]. Elevated levels of IL-4 and CCL26 have been found in ECRSwNP [ 162 ]. The stimulation of IL-4 has been found to lead to an increase in the stability of CCL26 mRNA, and the expression of CCL26 has been observed to be affected by the overexpression or knockdown of the human antigen R (HuR) [ 162 ], an RNA-binding protein of the ELAV protein family.…”

“…Elevated levels of IL-4 and CCL26 have been found in ECRSwNP [ 162 ]. The stimulation of IL-4 has been found to lead to an increase in the stability of CCL26 mRNA, and the expression of CCL26 has been observed to be affected by the overexpression or knockdown of the human antigen R (HuR) [ 162 ], an RNA-binding protein of the ELAV protein family. HuR plays a crucial role in various biological processes such as immune responses, cell proliferation, and differentiation [ 162 ].…”