Mechanical stress induces pre-B-cell colony-enhancing factor/NAMPT expression via epigenetic regulation by miR-374a and miR-568 in human lung endothelium

• Published in: American journal of respiratory cell and molecular biology Vol. 50; no. 2; pp. 409 - 418
• Main Authors: Adyshev, Djanybek M, Elangovan, Venkateswaran Ramamoorthi, Moldobaeva, Nurgul, Mapes, Brandon, Sun, Xiaoguang, Garcia, Joe G N
• Format: Journal Article
• Language: English
• Published: United States American Thoracic Society 01.02.2014
• Subjects: Apoptosis; Biomarkers; Biomedical research; Cell division; Cytokines - metabolism; DNA methylation; DNA repair; Endothelium; Endothelium - metabolism; Epigenesis, Genetic; Epigenetics; Experiments; Gene expression; Gene Expression Regulation - drug effects; Humans; Inflammation - genetics; Lipopolysaccharides - pharmacology; Lung - metabolism; Metabolic disorders; MicroRNAs; MicroRNAs - drug effects; MicroRNAs - genetics; MicroRNAs - metabolism; Nicotinamide Phosphoribosyltransferase - metabolism; Original Research; Pathogenesis; Permeability; Proteins; Pulmonary arteries; Respiratory distress syndrome; Respiratory Distress Syndrome, Adult - genetics; RNA, Messenger - genetics; RNA, Messenger - metabolism; Stress, Mechanical; Ventilator-Induced Lung Injury - genetics; Ventilator-Induced Lung Injury - metabolism
• ISSN: 1044-1549; 1535-4989
• DOI: 10.1165/rcmb.2013-0292oc

Increased lung vascular permeability and alveolar edema are cardinal features of inflammatory conditions such as acute respiratory distress syndrome (ARDS) and ventilator-induced lung injury (VILI). We previously demonstrated that pre-B-cell colony-enhancing factor (PBEF)/NAMPT, the proinflammatory cytokine encoded by NAMPT, participates in ARDS and VILI inflammatory syndromes. The present study evaluated posttranscriptional regulation of PBEF/NAMPT gene expression in human lung endothelium via 3'-untranslated region (UTR) microRNA (miRNA) binding. In silico analysis identified hsa-miR-374a and hsa-miR-568 as potential miRNA candidates. Increased PBEF/NAMPT transcription (by RT-PCR) and expression (by Western blotting) induced by 18% cyclic stretch (CS) (2 h: 3.4 ± 0.06 mRNA fold increase (FI); 10 h: 1.5 ± 0.06 protein FI) and by LPS (4 h: 3.8 ± 0.2 mRNA FI; 48 h: 2.6 ± 0.2 protein FI) were significantly attenuated by transfection with mimics of hsa-miR-374a or hsa-miR-568 (40-60% reductions each). LPS and 18% CS increased the activity of a PBEF/NAMPT 3'-UTR luciferase reporter (2.4-3.25 FI) with induction reduced by mimics of each miRNA (44-60% reduction). Specific miRNA inhibitors (antagomirs) for each PBEF/NAMPT miRNA significantly increased the endogenous PBEF/NAMPT mRNA (1.4-3.4 ± 0.1 FI) and protein levels (1.2-1.4 ± 0.1 FI) and 3'-UTR luciferase activity (1.4-1.7 ± 0.1 FI) compared with negative antagomir controls. Collectively, these data demonstrate that increased PBEF/NAMPT expression induced by bioactive agonists (i.e., excessive mechanical stress, LPS) involves epigenetic regulation with hsa-miR-374a and hsa-miR-568, representing novel therapeutic strategies to reduce inflammatory lung injury.