Decreased Epithelial and Plasma miR-181b-5p Expression Associates with Airway Eosinophilic Inflammation in Asthma.
Clin Exp Allergy. 2016 May 18;
Authors: Huo X, Zhang K, Yi L, Mo Y, Liang Y, Zhao J, Zhang Z, Xu Y, Zhen G
BACKGROUND: Airway eosinophilic inflammation is a pivotal feature of asthma. Epithelial cells play critical roles in airway eosinophilia. We hypothesized that epithelial microRNAs (miRNAs) are involved in airway eosinophilia.
OBJECTIVE: This study investigated the associations between epithelial and plasma miR-181b-5p and airway eosinophilic inflammation, and the possible mechanism by which miR-181b-5p participates in eosinophilic inflammation.
METHODS: Epithelial miRNAs expression was profiled by miRNA array in 8 subjects with asthma and 4 healthy controls. Epithelial miR-181b-5p expression was confirmed by quantitative PCR in the subjects for array experiment and another cohort including 21 subjects with asthma and 10 controls. Plasma miR-181b-5p was determined by quantitative PCR in 72 subjects with asthma and 35 controls. Correlation assays between epithelial or plasma miR-181b-5p expression and airway eosinophilia were performed. The target of miR-181b-5p, SPP1, was predicted by online algorithms and verified in BEAS-2B cells. The role of miR-181b-5p in epithelial proinflammatory cytokine expression was examined in an in vitro system.
RESULTS: Epithelial miR-181b-5p expression was decreased in subjects with asthma. Epithelial miR-181b-5p levels were inversely correlated with sputum and bronchial submucosal eosinophilia. Plasma miR-181b-5p was decreased and correlated with epithelial miR-181b-5p in subjects with asthma. There was a strong inverse correlation between plasma miR-181b-5p and airway eosinophilia in subjects with asthma. Plasma miR-181b-5p was increased after inhaled corticosteroids treatment. We verified that SPP1 is a target of miR-181b-5p. In human bronchial epithelial cells, miR-181b-5p regulated IL-13-induced IL-1? and CCL11 expression by targeting SPP1. Dexamethasone restored IL-13-induced miR-181b-5p downregulation and suppressed IL-13-induced SPP1, IL-1? and CCL11 expression.
CONCLUSIONS AND CLINICAL RELEVANCE: Epithelial and plasma miR-181b-5p are potential biomarkers for airway eosinophilia in asthma. MiR-181b-5p may participate in eosinophilic airway inflammation by regulating proinflammatory cytokines expression via targeting SPP1. This article is protected by copyright. All rights reserved.
PMID: 27192552 [PubMed – as supplied by publisher]
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