MicroRNA-146b inhibition augments hypoxia-induced cardiomyocyte apoptosis
MicroRNA-146b inhibition augments hypoxia-induced cardiomyocyte apoptosis
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MicroRNA-146b 抑制增强缺氧诱导的心肌细胞凋亡
DOI：
10.3892/mmr.2015.4333
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发表时间：
2015-11-01
影响因子：
3.4
通讯作者：
Xiao, Ying-Bin
中科院分区：
文献类型：
--
作者：
Li, Jing-Wei;He, Si-Yi;Xiao, Ying-Bin
MicroRNAs(MiRs)调节许多生理和病理过程，包括心肌慢性缺氧。以往的研究表明，在体外和体内，miR-146b的表达随着缺氧的诱导而增加。本研究探讨了miR-146b在低氧心肌细胞中的作用及其作用机制。采用逆转录-定量聚合酶链式反应检测先天性心脏病患者组织中miR-146b的表达。将miR-146b抑制剂导入大鼠心肌细胞系H9c2，培养72 h后，发现在低氧条件下，miR-146b的表达增加。末端脱氧核苷酸转移酶dUTP缺口末端标记、Hoechst 33258染色、JC-1分析(线粒体膜通透性测定)和Annexin V/碘化丙啶分析表明，miR-146b抑制物可增加乳酸脱氢酶的释放，增加缺氧诱导的细胞凋亡。Bcl2表达降低，Caspase3和Bax表达增强。Western印迹分析和双荧光素酶报告实验证实，核糖核酸酶L是miR-146b的直接靶点。此外，抑制miR-146b可增加核因子-kappaB和信号转导及转录激活子3的激活。结论：抑制miR-146b可能增加缺氧诱导的心肌细胞凋亡。
MicroRNAs (miRs) regulate a number of physiological and pathological processes, including myocardial chronic hypoxia. Previous studies revealed that the expression of miR-146b is increased in vitro and in vivo following the induction of hypoxia. In the present study, the role of miR-146b in hypoxic cardiomyocytes, and the mechanisms underlying its activity, were investigated. The expression of miR-146b was measured in tissue samples from patients with congenital heart disease by reverse transcription-quantitative polymerase chain reaction. The rat H9c2 cardiomyocyte cell line was transfected with an miR-146b inhibitor or the experimental controls, and the cells were maintained under hypoxic conditions for 72 h. The expression of miR-146b increased following the induction of hypoxia. Transfection with the miR-146b inhibitor enhanced the release of lactate dehydrogenase and increased hypoxia-induced apoptosis, as determined by terminal deoxynucleotidyl transferase dUTP nick-end labeling, Hoechst 33258 staining, JC-1 assay (measuring mitochondrial membrane permeability) and annexin V/propidium iodide analysis. A decreased expression of Bcl-2 was observed, whereas the expression levels of cleaved-caspase 3 and Bax were increased. Western blot analysis and a dual luciferase reporter assay confirmed that ribonuclease L is a direct target of miR-146b. Furthermore, inhibition of miR-146b increased the activation of nuclear factor-kappa B and signal transducer and activator of transcription 3. In conclusion, the inhibition of miR-146b may increase hypoxia-induced cardiomyocyte apoptosis.