Abstract：
Isoflurane, a commonly used inhaled anesthetic, has been found to have a cardioprotective effect. However, the precise mechanisms have not been fully elucidated. Here, we found that isoflurane preconditioning enhanced OGD/R-induced upregulation of miR-210, a hypoxia-responsive miRNA, in AC16 human myocardial cells. To further test the roles of miR-210 in regulating the effects of isoflurane preconditioning on OGD/R-induced cardiomyocyte injury, AC16 cells were transfected with anti-miR-210 or control anti-miRNA. Results showed that isoflurane preconditioning attenuated OGD/R-induced cardiomyocyte cytotoxicity (as assessed by cell viability, LDH and CK-MB levels), which could be reversed by anti-miR-210. Isoflurane preconditioning also prevented OGD/R-induced increase in apoptotic rate, caspase-3 and caspase-9 activities, and Bax level and decrease in Bcl-2 expression level, while anti-miR-210 blocked these effects. We also found that anti-miR-210 prevented the inhibitory effects of isoflurane preconditioning on OGD/R-induced decrease in adenosine triphosphate content; mitochondrial volume; citrate synthase activity; complex I, II, and IV activities; and p-DRP1 and MFN2 expression. Besides, the expression of BNIP3, a reported direct target of miR-210, was significantly decreased under hypoxia condition and could be regulated by isoflurane preconditioning. In addition, BNIP3 knockdown attenuated the effects of miR-210 silencing on the cytoprotection of isoflurane preconditioning. These findings suggested that isoflurane preconditioning exerted protective effects against OGD/R-induced cardiac cytotoxicity by regulating the miR-210/BNIP3 axis.
摘要：
异氟醚,一种常用的吸入麻醉剂，已经发现有心脏保护作用.然而,确切的机制尚未完全阐明。这里,我们发现异氟烷预处理增强了OGD/R诱导的miR-210的上调，在AC16人心肌细胞中。为了进一步研究miR-210在异氟烷预处理对OGD/R诱导的心肌细胞损伤的调控作用,用抗miR-210或对照抗miRNA转染AC16细胞。结果显示异氟烷预处理减弱了OGD/R诱导的心肌细胞的细胞毒性（通过细胞活力评估，LDH和CK-MB水平)，可以通过抗miR-210逆转。异氟醚预处理还可以防止OGD/R诱导的凋亡率增加，caspase-3和caspase-9活性，和Bax水平和Bcl-2表达水平的降低，而抗miR-210阻断了这些作用。我们还发现，抗miR-210阻止异氟烷预处理对OGD/R诱导的三磷酸腺苷含量降低的抑制作用;线粒体体积;柠檬酸合酶活性;复合物I,II,和IV活性;以及p-DRP1和MFN2表达。此外,报道的miR-210的直接靶标BNIP3的表达在缺氧条件下显着降低，并且可以通过异氟烷预处理进行调节。此外,BNIP3敲低减弱miR-210沉默对异氟烷预处理的细胞保护作用。这些发现表明异氟烷预处理通过调节miR-210/BNIP3轴对OGD/R诱导的心脏细胞毒性具有保护作用。
