Hydroxytyrosol modulates the levels of microRNA-9 and its target sirtuin-1 thereby counteracting oxidative stress-induced chondrocyte death
Hydroxytyrosol modulates the levels of microRNA-9 and its target sirtuin-1 thereby counteracting oxidative stress-induced chondrocyte death
复制标题
DOI：
10.1016/j.joca.2016.11.014
复制
发表时间：
2017-04-01
影响因子：
7
通讯作者：
Flamigni, F.
中科院分区：
文献类型：
--
作者：
D'Adamo, S.;Cetrullo, S.;Flamigni, F.
目的：已发现营养化合物，如羟基酪醇（HT），通过影响软骨细胞中的多种关键分子和细胞过程而在骨关节炎（OA）中发挥保护作用。然而，据我们所知，在OA模型中，营养品和microRNA（miR）网络之间没有关系。在这里，我们确定了一个miR的参与HT介导的软骨保护氧化应激条件下，通过靶向sirtuin-1（SIRT-1）。方法：人的主要和C-28/12软骨细胞预处理100 μ M HT 30分钟前，100 μ M H2 O2添加。利用计算机模拟分析来选择能够靶向SIRT-1 mRNA的推定候选miR。采用基于荧光素酶的基因报告分析来证明miR-9与其推定的mRNA靶标之间的直接联系。瞬时转染法检测miR-9水平对caspase活性、细胞存活率和OA相关基因表达的影响。MiR-9和SIRT-1水平在H2 O2和HT处理后的软骨细胞中显示出相反的变化。此外，miR-9沉默抑制H2 O2诱导的细胞死亡部分是通过下调SIRT-1，而miR-9过表达显著降低HT的保护作用。结论：miR-9是氧化应激对软骨细胞的损伤和OA相关效应的重要介导因子，而miR-9的表达调控可能是HT保护软骨细胞的重要机制。(C)2016国际骨关节炎研究学会。由爱思唯尔有限公司出版。保留所有权利。
Objective: Nutraceutical compounds, such as hydroxytyrosol (HT), have been found to exert protective effects in osteoarthritis (OA) by affecting a variety of key molecular and cellular processes in chondrocytes. However, to our knowledge, no relationship has been reported between nutraceuticals and microRNA (miR) network in OA models. Here, we identified a miR that is implicated in HT-mediated chondroprotection following oxidative stress condition by targeting sirtuin-1 (SIRT-1).Methods: Human primary and C-28/12 chondrocytes were pre-treated with 100 mu M HT 30 min before 100 mu M H2O2 addition. In silico analyses were exploited to select putative candidate miRs able to target SIRT-1 mRNA. Luciferase-based gene reporter assay was employed to demonstrate the direct link between miR-9 and its putative mRNA target. Transient transfection approach was performed to examine the effects of miR-9 levels on caspase activity, cell viability and expression of OA-related genes.Results: MiR-9 was identified and confirmed as a post-transcriptional regulator of SIRT-1. MiR-9 and SIRT-1 levels showed opposite changes in chondrocytes following H2O2 and HT treatment. Moreover mir-9 silencing inhibited cell death induced by H2O2 partly through down-regulation of SIRT-1, whereas miR-9 overexpression markedly reduced the protective effect of HT. The manipulation of miR-9 levels also resulted in the modulation of OA-related gene expression, including MMP-13, VEGF and RUNX-2.Conclusions: These results show that miR-9 is a critical mediator of the deleterious and OA-related effects of oxidative stress in chondrocytes and that modulation of miR expression may be a crucial mechanism underlying the protective action of HT. (C) 2016 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.