Simvastatin Treatment Protects Myocardium in Noncoronary Artery Cardiac Surgery by Inhibiting Apoptosis Through miR-15a-5p Targeting
Simvastatin Treatment Protects Myocardium in Noncoronary Artery Cardiac Surgery by Inhibiting Apoptosis Through miR-15a-5p Targeting
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辛伐他汀治疗通过 miR-15a-5p 靶向抑制细胞凋亡来保护非冠状动脉心脏手术中的心肌
DOI：
10.1097/fjc.0000000000000611
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发表时间：
2018-10-01
影响因子：
3
通讯作者：
Ou，Jing-Song
中科院分区：
文献类型：
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作者：
Zhou，Li;Liu，Xiang;Ou，Jing-Song
摘要：辛伐他汀治疗对非冠状动脉心脏手术患者具有心脏保护作用。然而，辛伐他汀治疗在这些情况下保护心肌的机制尚不完全清楚。我们的临床研究纳入了70例接受非冠状动脉心脏手术的患者，其中35例来自辛伐他汀治疗组，35例来自对照治疗组。术前给予辛伐他汀（20mg /d） 5-7天。术前、术后分别行心肌组织活检。TUNEL染色检测细胞凋亡。免疫印迹法检测心肌组织中Bcl-2、Bak的表达。采用实时定量聚合酶链反应法检测miRNA和Bcl-2 mRNA的表达。分离大鼠心肌细胞，培养细胞。将MiR-15a-5p mimic转染到心肌细胞中，通过免疫印迹法检测Bcl-2。TUNEL染色显示，辛伐他汀治疗组心肌细胞凋亡明显少于对照组。辛伐他汀治疗组术前Bcl-2蛋白表达升高，对照组术后Bak蛋白表达升高。进一步比较发现，术后对照治疗组Bcl-2/Bak比值降低，辛伐他汀治疗组Bcl-2/Bak比值无明显变化。此外，微阵列检测显示，辛伐他汀治疗显著降低了miR-15a-5p。通过实时定量聚合酶链反应分析证实了这一点。预测MiR-15a-5p在核苷酸位置2529-2536靶向Bcl-2 mRNA。荧光素酶结合实验证实了这一点。与miR-15a-5p的变化一致，辛伐他汀治疗组Bcl-2 mRNA表达升高。MiR-15a-5p mimic显著抑制心肌细胞Bcl-2表达。我们的研究结果强烈表明，辛伐他汀术前治疗可以通过抑制miR-15a-5p表达抑制细胞凋亡，从而增加Bcl-2的表达，降低Bak的表达，至少在一定程度上保护非冠状动脉心脏手术患者的心肌。
Abstract: Simvastatin treatment is cardioprotective in patients undergoing noncoronary artery cardiac surgery. However, the mechanisms by which simvastatin treatment protects the myocardium under these conditions are not fully understood. Seventy patients undergoing noncoronary cardiac surgery, 35 from a simvastatin treatment group and 35 from a control treatment group, were enrolled in our clinical study. Simvastatin (20 mg/d) was administered preoperatively for 5–7 days. Myocardial tissue biopsies were taken before and after surgery. Apoptosis was detected by TUNEL staining. The expressions of Bcl-2 and Bak in myocardial tissue were detected by immunoblotting. The expressions of miRNA and Bcl-2 mRNA were detected by quantitative real-time polymerase chain reaction assays. Cardiomyocytes were isolated from rat and cultured cells. MiR-15a-5p mimic was transfected into cardiomyocytes, and the Bcl-2 was detected by immunoblotting. TUNEL staining showed significantly less myocardial apoptosis in the simvastatin treatment group when compared with the control treatment group. Protein expression of Bcl-2 was increased in the simvastatin treatment group before surgery, and Bak expression was increased in the control treatment group after surgery. Further comparisons showed that Bcl-2/Bak ratios were reduced in the control treatment group but were not significantly changed in the simvastatin treatment group after surgery. Furthermore, microarray assays revealed that miR-15a-5p was significantly decreased by simvastatin treatment. This was validated by quantitative real-time polymerase chain reaction analysis. MiR-15a-5p was predicted to target Bcl-2 mRNA at nucleotide positions 2529–2536. This was validated by luciferase binding assays. Coincident with the change in miR-15a-5p, the mRNA expression of Bcl-2 was increased in the simvastatin treatment group. MiR-15a-5p mimic significantly inhibited Bcl-2 expression in cardiomyocytes. Our findings strongly suggest that simvastatin treatment preoperatively protected the myocardium in patients undergoing noncoronary artery cardiac surgery, at least in part, by inhibiting apoptosis via suppressing miR-15a-5p expression, leading to increasing expression of Bcl-2 and decreasing expression of Bak.