MicroRNA-217 regulates interstitial pneumonia via IL-6

Abstract

The aim of this study was to investigate the expression of miRNA-217 in pulmonary macrophages, blood mononuclear cells and serum in patients with interstitial pneumonia, and the role of miRNA-217 in interstitial pneumonia. Blood and bronchoalveolar lavage fluid specimens from 29 patients with interstitial pneumonia and 23 healthy people (controls) in the same period were collected. Lung macrophages were isolated from the bronchoalveolar lavage fluid and were cultured. The expression of miRNA-217 and IL-6 mRNA in lung macrophages, blood mononuclear cells and serum samples were detected by quantitative real-time PCR (qRT-PCR). The IL-6 protein expression levels in lung macrophages, blood mononuclear cells and serum samples were detected by Western Blot or enzyme-linked immunosorbent assay, whereas IL-6 is a direct target gene of miRNA-217 was analyzed by double-luciferase reporter assay. The results showed that IL-6 was up-regulated, whereas miRNA-217 was down-regulated in lung macrophages, blood mononuclear cells and serum samples in patients with interstitial pneumonia (P < 0.05). IL-6 was suggested to be the target gene of miRNA-217 by double-luciferase reporter assay. We speculate that the upregulation of IL-6 expression in lung macrophages, blood mononuclear cells and serum in patients with interstitial pneumonia may be related to the down-regulation of miRNA-217 expression, which may mediate interstitial pneumonia through IL-6.