Table of Contents Author Guidelines Submit a Manuscript
Mediators of Inflammation
Volume 2014, Article ID 379537, 12 pages
http://dx.doi.org/10.1155/2014/379537
Research Article

MicroRNA-146a Decreases High Glucose/Thrombin-Induced Endothelial Inflammation by Inhibiting NAPDH Oxidase 4 Expression

1School of Medicine, China Medical University, No. 91, Hsueh-Shih Road, Taichung 40402, Taiwan
2Division of Cardiology, Department of Medicine, China Medical University Hospital, No. 2, Yuh-Der Road, Taichung 40447, Taiwan
3Department of Biotechnology, College of Medical and Health Science, Asia University, No. 500, Lioufeng Road, Wufeng, Taichung 41354, Taiwan
4Graduate Institute of Basic Medical Science, China Medical University, No. 91, Hsueh-Shih Road, Taichung 40402, Taiwan
5Department of Life Science, National Chung Hsing University, No. 250, Kuo-Kuang Road, Taichung 40227, Taiwan
6Graduate Integration of Chinese and Western Medicine, China Medical University, No. 91, Hsueh-Shih Road, Taichung 40402, Taiwan
7Department of Pediatrics, Children’s Hospital, China Medical University Hospital, No. 2, Yuh-Der Road, Taichung 40447, Taiwan
8Department of Biotechnology, Asia University, No. 500, Lioufeng Road, Wufeng, Taichung 41354, Taiwan

Received 23 May 2014; Revised 10 August 2014; Accepted 10 August 2014; Published 14 September 2014

Academic Editor: Yung-Hsiang Chen

Copyright © 2014 Huang-Joe Wang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Diabetes is associated with hyperglycemia and increased thrombin production. However, it is unknown whether a combination of high glucose and thrombin can modulate the expression of NAPDH oxidase (Nox) subtypes in human aortic endothelial cells (HAECs). Moreover, we investigated the role of a diabetes-associated microRNA (miR-146a) in a diabetic atherothrombosis model. We showed that high glucose (HG) exerted a synergistic effect with thrombin to induce a 10.69-fold increase in Nox4 mRNA level in HAECs. Increased Nox4 mRNA expression was associated with increased Nox4 protein expression and ROS production. Inflammatory cytokine kit identified that the treatment increased IL-8 and IL-6 levels. Moreover, HG/thrombin treatment caused an 11.43-fold increase of THP-1 adhesion to HAECs. In silico analysis identified the homology between miR-146a and the 3′-untranslated region of the Nox4 mRNA, and a luciferase reporter assay confirmed that the miR-146a mimic bound to this Nox4 regulatory region. Additionally, miR-146a expression was decreased to 58% of that in the control, indicating impaired feedback restraint of HG/thrombin-induced endothelial inflammation. In contrast, miR-146a mimic transfection attenuated HG/thrombin-induced upregulation of Nox4 expression, ROS generation, and inflammatory phenotypes. In conclusion, miR-146a is involved in the regulation of endothelial inflammation via modulation of Nox4 expression in a diabetic atherothrombosis model.