Divergent Effects of miR-181 Family Members on Myocardial Function Through Protective Cytosolic and Detrimental Mitochondrial microRNA Targets.
Divergent Effects of miR-181 Family Members on Myocardial Function Through Protective Cytosolic and Detrimental Mitochondrial microRNA Targets.
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DOI：
10.1161/jaha.116.004694
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发表时间：
2017-02-27
影响因子：
5.4
通讯作者：
Steenbergen C
中科院分区：
文献类型：
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作者：
Das S;Kohr M;Dunkerly-Eyring B;Lee DI;Bedja D;Kent OA;Leung AK;Henao-Mejia J;Flavell RA;Steenbergen C
MicroRNA(MiRNA)是一种非编码RNA，可以通过转录后调节抑制靶基因的表达。除了miRNAs的众多生理作用外，它们在影响心血管健康的病理生理过程中也发挥着重要作用。此前，我们报道了心肌线粒体中存在核编码的microRNA(miR-181c)，重要的是，它的过度表达通过调节线粒体基因的表达来影响线粒体的功能。为了进一步研究miR-181家族如何影响心脏，我们使用包含10个重复的互补miR-181“种子”序列的miR-181-海绵抑制miR-181，并通过稳定表达扰乱的或miR-181-海绵序列产生了一组H9c2细胞，这是一种来自大鼠成肌细胞的细胞系。海绵-H9c2细胞显示活性氧产生减少，线粒体基础呼吸减少，并对阿霉素诱导的氧化应激具有保护作用。我们还发现miR-181a/b靶向磷酸酶和张力蛋白同源蛋白(PTEN)，海绵表达的稳定细胞增加了PTEN的活性，降低了PI3K信号转导。此外，我们还使用了miR-181a/b−/−和miR-181c/d−/−基因敲除小鼠，并对它们进行了缺血再灌注损伤。我们的结果表明不同的miR-181家族成员的作用不同：miR-181a/b靶向胞浆中的PTEN，由于PTEN信号的增加而导致MIR-181a/b−/−小鼠的梗塞面积增加，而MIR-181c靶向线粒体中的mt-COX1，导致MIR-181c/d−/−小鼠的梗塞面积减小。MiR-181家族通过靶向Mt-COX1(miR-181c)或靶向PTEN(miR-181a/b)来改变心肌对氧化应激的反应，特别是具有有害影响。
MicroRNA (miRNA) is a type of noncoding RNA that can repress the expression of target genes through posttranscriptional regulation. In addition to numerous physiologic roles for miRNAs, they play an important role in pathophysiologic processes affecting cardiovascular health. Previously, we reported that nuclear encoded microRNA (miR‐181c) is present in heart mitochondria, and importantly, its overexpression affects mitochondrial function by regulating mitochondrial gene expression. To investigate further how the miR‐181 family affects the heart, we suppressed miR‐181 using a miR‐181‐sponge containing 10 repeated complementary miR‐181 “seed” sequences and generated a set of H9c2 cells, a cell line derived from rat myoblast, by stably expressing either a scrambled or miR‐181‐sponge sequence. Sponge‐H9c2 cells showed a decrease in reactive oxygen species production and reduced basal mitochondrial respiration and protection against doxorubicin‐induced oxidative stress. We also found that miR‐181a/b targets phosphatase and tensin homolog (PTEN), and the sponge‐expressing stable cells had increased PTEN activity and decreased PI3K signaling. In addition, we have used miR‐181a/b−/− and miR‐181c/d−/− knockout mice and subjected them to ischemia‐reperfusion injury. Our results suggest divergent effects of different miR‐181 family members: miR‐181a/b targets PTEN in the cytosol, resulting in an increase in infarct size in miR‐181a/b−/− mice due to increased PTEN signaling, whereas miR‐181c targets mt‐COX1 in the mitochondria, resulting in decreased infarct size in miR‐181c/d−/− mice. The miR‐181 family alters the myocardial response to oxidative stress, notably with detrimental effects by targeting mt‐COX1 (miR‐181c) or with protection by targeting PTEN (miR‐181a/b).