抑制 miR-23a 通过靶向 PGC-1α/Drp1 通路减轻阿霉素诱导的线粒体依赖性心肌细胞凋亡。
Inhibition of miR-23a attenuates doxorubicin-induced mitochondria-dependent cardiomyocyte apoptosis by targeting the PGC-1α/Drp1 pathway.
机构信息
Institute of Clinical Pharmacology, the Second Affiliated Hospital of Harbin Medical University (The University Key Laboratory of Drug Research, Heilongjiang Province), Harbin 150086, PR China; Department of Clinical Pharmacology, College of Pharmacy, Harbin Medical University, Harbin 150081, PR China.
Institute of Clinical Pharmacology, the Second Affiliated Hospital of Harbin Medical University (The University Key Laboratory of Drug Research, Heilongjiang Province), Harbin 150086, PR China; State Key Laboratory of Quality Research in Chinese Medicines, Macau University of Science and Technology, Macau, PR China; Department of Clinical Pharmacology, College of Pharmacy, Harbin Medical University, Harbin 150081, PR China.
出版信息
Toxicol Appl Pharmacol. 2019 Apr 15;369:73-81. doi: 10.1016/j.taap.2019.02.016. Epub 2019 Mar 1.
BACKGROUND AND PURPOSE
Doxorubicin (Dox)-induced cardiotoxicity limits its clinical use. A number of microRNAs (miRs) have been found essential in Dox-induced cardiotoxicity. The aim of the present study was to elucidate the effects of miR-23a on Dox-induced cardiomyocyte apoptosis and underlying mechanisms.
EXPERIMENTAL APPROACH
Dox-induced cardiotoxicity model was established in primary neonatal rat ventricular myocytes (NRVMs). MTT assay, Live/Dead staining was employed to examine the viability and cell death of NRVMs. Mitochondrial membrane potential (MMP) and reactive oxygen species (ROS) were measured. Protein levels of mitochondria biogenesis and fission/fusion associated factors including peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α), dynamin-related protein-1 (Drp1) and mitofusin 2 (Mfn2) were detected. Meanwhile, apoptosis-related cytochrome c (Cyt c) and caspase-3 expression were examined by western blot. PGC-1α siRNA was employed to validate the role of miR-23a in Dox-induced cardiotoxicity.
KEY RESULTS
MiR-23a expression was significantly increased by Dox concentration-dependently. Inhibition of miR-23a markedly increased viability and MMP, reduced cell death and ROS production of NRVMs. MiR-23a mimic significantly inhibited expression of its target PGC-1α. MiR-23a inhibitor significantly diminished phosphorylation of Drp1 without affecting Mfn2 expression. Protein expression of Cyt c and cleaved caspase-3 were markedly inhibited by miR-23a inhibitor. The protective effects of miR-23a inhibitor were reversed by PGC-1α siRNA.
CONCLUSIONS AND IMPLICATIONS
Increased miR-23a promoted mitochondrial injury in the Dox-induced cellular model. Inhibition of miR-23a attenuated cardiomyocyte damage by directly targeting PGC-1α/p-Drp1, thereby inhibiting mitochondria-dependent apoptosis. These findings may provide a new potential target for the treatment of Dox-induced cardiotoxicity.
背景与目的
多柔比星（Dox）诱导的心脏毒性限制了其临床应用。许多 microRNAs（miRs）已被发现对 Dox 诱导的心脏毒性至关重要。本研究旨在阐明 miR-23a 对 Dox 诱导的心肌细胞凋亡的影响及其潜在机制。
实验方法
在原代新生大鼠心室肌细胞（NRVMs）中建立 Dox 诱导的心脏毒性模型。MTT 法、Live/Dead 染色检测 NRVMs 的活力和细胞死亡。测量线粒体膜电位（MMP）和活性氧（ROS）。检测线粒体生物发生和分裂/融合相关因子的蛋白水平，包括过氧化物酶体增殖物激活受体γ共激活因子 1α（PGC-1α）、动力相关蛋白 1（Drp1）和线粒体融合蛋白 2（Mfn2）。同时，Western blot 检测凋亡相关细胞色素 c（Cyt c）和半胱天冬酶-3 的表达。用 PGC-1α siRNA 验证 miR-23a 在 Dox 诱导的心脏毒性中的作用。
主要结果
Dox 浓度依赖性地上调了 miR-23a 的表达。抑制 miR-23a 显著增加了 NRVMs 的活力和 MMP，降低了细胞死亡和 ROS 产生。miR-23a 模拟物显著抑制了其靶基因 PGC-1α 的表达。miR-23a 抑制剂显著降低了 Drp1 的磷酸化而不影响 Mfn2 的表达。miR-23a 抑制剂明显抑制了 Cyt c 和 cleaved caspase-3 的蛋白表达。miR-23a 抑制剂的保护作用被 PGC-1α siRNA 逆转。
结论和意义
miR-23a 的上调促进了 Dox 诱导的细胞模型中线粒体的损伤。抑制 miR-23a 通过直接靶向 PGC-1α/p-Drp1 减轻心肌细胞损伤，从而抑制线粒体依赖性凋亡。这些发现可能为治疗 Dox 诱导的心脏毒性提供一个新的潜在靶点。
Zotero 插件