MicroRNA-146a-5p Mediates High Glucose-Induced Endothelial Inflammation via Targeting Interleukin-1 Receptor-Associated Kinase 1 Expression.

Wan-Yu Lo,Ching-Tien Peng,Huang-Joe Wang

doi:10.3389/fphys.2017.00551

Abstract

Background and Aims: Interleukin-1 receptor-associated kinase-1 (IRAK-1) is critical for mediating toll-like receptor and interleukin-1 receptor signaling. In this study, we have examined whether IRAK-1 expression is altered in high glucose (HG)-stimulated human aortic endothelial cells (HAECs), and whether microRNAs (miRs) target IRAK-1 to regulate HG-induced endothelial inflammation.Methods: HAECs were treated with HG for 24 and 48 h. Real-time PCR, Western blot, monocyte adhesion assay, bioinformatics analysis, TaqMan® arrays, microRNA mimic or inhibitor transfection, luciferase reporter assay and siRNA IRAK-1 transfection were performed. The aortic tissues from db/db type 2 diabetic mice were examined by immunohistochemistry staining.Results: HG time-dependently increased IRAK-1 mRNA and protein levels in HAECs, and was associated with increased VCAM-1/ICAM-1 gene expression and monocyte adhesion. Bioinformatic analysis, TaqMan® arrays, and real-time PCR were used to confirm that miR-146a-5p, miR-339-5p, and miR-874-3p were significantly downregulated in HG-stimulated HAECs, suggesting impaired feedback restraints on HG-induced endothelial inflammation via IRAK-1. However, only miR-146a-5p mimic transfection reduced the HG-induced upregulation of IRAK-1 expression, VCAM-1/ICAM-1 expression, and monocyte adhesion. Additionally, IRAK-1 depletion reduced HG-induced VCAM-1/ICAM-1 gene expression, and monocyte adhesion, indicating that HG-induced endothelial inflammation was mediated partially through IRAK-1. In vivo, intravenous injections of miR-146a-5p mimic prevented endothelial IRAK-1 and ICAM-1 expression in db/db mice.Conclusion: These results suggest that miR-146a-5p is involved in the regulation of HG-induced endothelial inflammation via modulation of IRAK-1; indicating that miR-146a-5p may be a novel target for the treatment of diabetic vascular complications.

Highlights

The increasing number of people with obesity, advanced age, and physically inactive lifestyles contributes to the increased incidence of diabetes, which had an estimated global prevalence of 6.4% in 2010 (Shaw et al, 2010)
Following the recruitment of adaptor molecules, including myeloid differentiation primary response protein (MYD88), the downstream signaling pathways involve the interaction of interleukin-1 receptor-associated kinase 1 (IRAK-1) and TNF receptor-associated factor 6 (TRAF-6) (Flannery and Bowie, 2010)
We first determined the effects of high glucose (HG) on endothelial Interleukin-1 receptor activated kinases (IRAKs)-1 expression

Summary

Introduction

The increasing number of people with obesity, advanced age, and physically inactive lifestyles contributes to the increased incidence of diabetes, which had an estimated global prevalence of 6.4% in 2010 (Shaw et al, 2010). Interleukin-1 receptor activated kinases (IRAKs) are the key mediators of innate immunity. IRAK-1 was the first to be identified; its role as an adaptor and kinase is essential for the toll-like receptor (TLR) and interleukin-1 receptor (IL-1R) signaling pathways, which regulate cellular inflammation (Gottipati et al, 2008). Following the recruitment of adaptor molecules, including myeloid differentiation primary response protein (MYD88), the downstream signaling pathways involve the interaction of interleukin-1 receptor-associated kinase 1 (IRAK-1) and TNF receptor-associated factor 6 (TRAF-6) (Flannery and Bowie, 2010). Innate immunity-induced inflammation is important for the pathogenesis and disease progression of both type 1 and type 2 diabetes (Prajapati et al, 2014; Cabrera et al, 2016; Wada and Makino, 2016; Mistry et al, 2017). We have examined whether IRAK-1 expression is altered in high glucose (HG)-stimulated human aortic endothelial cells (HAECs), and whether microRNAs (miRs) target IRAK-1 to regulate HG-induced endothelial inflammation

Methods

Results

Conclusion