MiR-155 Promotes ox-LDL-Induced Autophagy in Human Umbilical Vein Endothelial Cells.

Zhaozhi Zhang,Yuan Wang,Aijun Ma,Shaonan Yang,Kun Wang,Xudong Pan,Shihai Liu,Ting Li

doi:10.1155/2017/9174801

Abstract

As an evolutionarily conserved metabolic process, autophagy is involved in the process of atherosclerosis (AS). MicroRNA-155 (miR-155), a multifunctional miRNA, plays an important role in many physiological and pathological conditions, including AS and autophagy. However, the effect of miR-155 on the regulation of autophagy in endothelial cells has not been reported to date. Therefore, the objective of our study was to investigate the role of miR-155 in autophagy induced by oxidized low-density lipoprotein (ox-LDL) in human umbilical vein endothelial cells (HUVECs). Our results demonstrated that ox-LDL induced autophagy in HUVECs and increased the expression of miR-155 significantly. Overexpression of miR-155 improved autophagic activity, whereas low expression of miR-155 inhibited autophagic activity. Therefore, the data demonstrated that miR-155 has a modulating effect on the autophagy of vascular endothelial cells.

Highlights

Autophagy is an evolutionarily conserved metabolic process in which denatured proteins and damaged organelles are degraded through the lysosomal system for the maintenance of intracellular homeostasis during various stress conditions [1, 2]
Previous studies have indicated that oxidized low-density lipoprotein (ox-LDL) can result in autophagy in endothelial cells
Nowicki et al [20] reported that many autophagosomes with double membranes were observed in the EA.hy926 endothelial cells treated with ox-LDL for 6 h

Summary

Introduction

Autophagy is an evolutionarily conserved metabolic process in which denatured proteins and damaged organelles are degraded through the lysosomal system for the maintenance of intracellular homeostasis during various stress conditions [1, 2]. MicroRNAs (miRNAs) are a class of endogenous noncoding small RNA molecules that regulate gene expression and mediate posttranscriptional gene silencing by combining with the 3′-untranslaed region (3′-UTR) of the target mRNAs [7]. These RNAs are involved in the regulation of multiple cellular processes, including proliferation, differentiation, development, and apoptosis, [8] and have been associated with AS [9,10,11] and autophagy [12, 13]. Some studies have demonstrated that miR-155 could regulate the autophagy of tumor cells [16] and macrophages [17]. The goal of this study was to investigate the role of miR-155 in autophagy mediated by ox-LDL in HUVECs

Objectives

Results

Conclusion