Heart Center, The First Hospital of Lanzhou University, Lanzhou, Gansu, China.
Gansu Clinical Medical Research Center for Cardiovascular Diseases, The First Hospital of Lanzhou University, Lanzhou, Gansu, China.
Cell Prolif. 2020 Jun;53(6):e12818. doi: 10.1111/cpr.12818. Epub 2020 May 28.
Myocardial ischaemia/reperfusion (MI/R) injury is associated with adverse cardiovascular outcomes after acute myocardial infarction. However, the molecular mechanisms underlying MI/R injury are unclear. This study investigated the role of long non-coding RNA (lncRNA) Oip5-as1 in regulating mitochondria-mediated apoptosis during MI/R injury.
Sprague-Dawley rats were subjected to MI/R induced by ligation of the left anterior descending coronary artery followed by reperfusion. H9c2 cells were incubated under oxygen-glucose deprivation/reoxygenation (OGD/R) conditions to mimic in vivo MI/R. RT-qPCR and Western blot were used to evaluate gene and protein levels. CCK-8 assay, biochemical assay and flow cytometric analysis were performed to assess the function of Oip5-as1. The dual-luciferase gene reporter assay and RIP assay were conducted as needed.
Oip5-as1 expression was downregulated in the hearts of rats with MI/R and in H9c2 cells treated with OGD/R. Oip5-as1 overexpression alleviated reactive oxygen species-driven mitochondrial injury and consequently decreased apoptosis in MI/R rats and H9c2 cells exposed to OGD/R. Mechanistically, Oip5-as1 acted as a competing endogenous RNA of miR-29a and thus decreased its expression. Inhibition of miR-29a reduced the oxidative stress and cytotoxicity induced by OGD/R. Overexpression of miR-29a reversed the anti-apoptotic effect of Oip5-as1 in H9c2 cells treated with OGD/R. Further experiments identified SIRT1 as a downstream target of miR-29a. Oip5-as1 upregulated SIRT1 expression and activated the AMPK/PGC1α pathway by targeting miR-29a, thus reducing the apoptosis triggered by OGD/R. However, these effects were reversed by a selective SIRT1 inhibitor, EX527.
Oip5-as1 suppresses miR-29a leading to activation of the SIRT1/AMPK/PGC1α pathway, which attenuates mitochondria-mediated apoptosis during MI/R injury. Our findings thus provide new insights into the molecular mechanisms of MI/R injury.
心肌缺血/再灌注（MI/R）损伤与急性心肌梗死（AMI）后不良心血管结局有关。然而，MI/R 损伤的分子机制尚不清楚。本研究探讨了长链非编码 RNA（lncRNA）Oip5-as1 在调节 MI/R 损伤中线粒体介导的细胞凋亡中的作用。
结扎左前降支冠状动脉后再灌注，建立 Sprague-Dawley 大鼠 MI/R 模型。在氧葡萄糖剥夺/复氧（OGD/R）条件下孵育 H9c2 细胞，模拟体内 MI/R。采用 RT-qPCR 和 Western blot 检测基因和蛋白水平。采用 CCK-8 测定、生化测定和流式细胞术分析评估 Oip5-as1 的功能。根据需要进行双荧光素酶基因报告实验和 RIP 实验。
MI/R 大鼠心脏和 OGD/R 处理的 H9c2 细胞中 Oip5-as1 表达下调。Oip5-as1 过表达减轻了活性氧驱动的线粒体损伤，从而减少了 MI/R 大鼠和暴露于 OGD/R 的 H9c2 细胞的凋亡。机制上，Oip5-as1 作为 miR-29a 的竞争性内源性 RNA，从而降低其表达。抑制 miR-29a 减轻了 OGD/R 诱导的氧化应激和细胞毒性。在 OGD/R 处理的 H9c2 细胞中，过表达 miR-29a 逆转了 Oip5-as1 的抗凋亡作用。进一步的实验确定 SIRT1 是 miR-29a 的下游靶标。Oip5-as1 通过靶向 miR-29a 上调 SIRT1 表达并激活 AMPK/PGC1α 通路，从而减少 OGD/R 触发的细胞凋亡。然而，这些作用被 SIRT1 选择性抑制剂 EX527 逆转。
Oip5-as1 抑制 miR-29a 导致 SIRT1/AMPK/PGC1α 通路激活，减轻 MI/R 损伤中线粒体介导的细胞凋亡。我们的研究结果为 MI/R 损伤的分子机制提供了新的见解。
