Oxidative Stress-Induced miR-200c Disrupts the Regulatory Loop Among SIRT1, FOXO1, and eNOS
Oxidative Stress-Induced miR-200c Disrupts the Regulatory Loop Among SIRT1, FOXO1, and eNOS
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DOI：
10.1089/ars.2016.6643
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发表时间：
2017-08-20
影响因子：
6.6
通讯作者：
Magenta, Alessandra
中科院分区：
文献类型：
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作者：
Carlomosti, Fabrizio;D'Agostino, Marco;Magenta, Alessandra
目的：活性氧（ROS）在不同的病理状况（包括缺血，糖尿病和衰老）中起关键作用。我们先前表明ROS增强了miR-200c表达，从而导致内皮细胞（EC）凋亡和衰老。在此，我们在调节EC功能和ROS产生的三种严格相关的蛋白质中剖析了相互作用：SIRTUIN 1（SIRT1），内皮一氧化氮合酶（ENOS）（ENOS）和Forkhead Box O1（FoxO1）。此外，还研究了miR-200c在ROS调制中的作用。逆转：我们证明miR-200c直接靶向SIRT1，ENOS和FOXO1。通过这种机制，miR-200c降低了NO并增加了SIRT1靶标的乙酰化，即FOXO1和p53。 FOXO1乙酰化抑制了其对靶基因的转录活性，即SIRT1和ROS清除剂，过氧化氢酶和锰超氧化物歧化酶。在保持时，miR-200C增加了ROS的产生，并在Ser-36中诱导P66SHC蛋白磷酸化；该机制上调ROS并抑制FOXO1转录，从而加强了该分子电路。这些体外结果在三个体内氧化应激模型中得到了验证，即来自旧供体的人体皮肤成纤维细胞，来自老鼠的股骨动脉和一种后肢缺血的鼠模型。在所有情况下，miR-200c与对照相比较高，即SIRT1，ENOS和FOXO1的靶标被下调。在小鼠后肢缺血模型中，抗MIR-200C治疗挽救了这些靶标并改善了肢体灌注。结论和结论：miR-200C破坏SIRT1/FOXO1/ENOS调节循环。该事件促进ROS的产生并减少NO，在氧化应激（如衰老和缺血）的情况下导致内皮功能障碍。
Aims: Reactive oxygen species (ROS) play a pivotal role in different pathologic conditions, including ischemia, diabetes, and aging. We previously showed that ROS enhance miR-200c expression, causing endothelial cell (EC) apoptosis and senescence. Herein, we dissect the interaction among miR-200c and three strictly related proteins that modulate EC function and ROS production: sirtuin 1 (SIRT1), endothelial nitric oxide synthase (eNOS), and forkhead box O1 (FOXO1). Moreover, the role of miR-200c on ROS modulation was also investigated.Results: We demonstrated that miR-200c directly targets SIRT1, eNOS, and FOXO1; via this mechanism, miR-200c decreased NO and increased the acetylation of SIRT1 targets, that is, FOXO1 and p53. FOXO1 acetylation inhibited its transcriptional activity on target genes, that is, SIRT1 and the ROS scavengers, catalase and manganese superoxide dismutase. In keeping, miR-200c increased ROS production and induced p66Shc protein phosphorylation in Ser-36; this mechanism upregulated ROS and inhibited FOXO1 transcription, reinforcing this molecular circuitry. These in vitro results were validated in three in vivo models of oxidative stress, that is, human skin fibroblasts from old donors, femoral arteries from old mice, and a murine model of hindlimb ischemia. In all cases, miR-200c was higher versus control and its targets, that is, SIRT1, eNOS, and FOXO1, were downmodulated. In the mouse hindlimb ischemia model, anti-miR-200c treatment rescued these targets and improved limb perfusion.Innovation and Conclusion: miR-200c disrupts SIRT1/FOXO1/eNOS regulatory loop. This event promotes ROS production and decreases NO, contributing to endothelial dysfunction under conditions of increased oxidative stress such as aging and ischemia.