Department of Internal Medicine and Cardiology, China‑Japan Union Hospital of Jilin University, Changchun, Jilin 130033, P.R. China.
Department of Orthopedics, China‑Japan Union Hospital of Jilin University, Changchun, Jilin 130033, P.R. China.
Mol Med Rep. 2018 Mar;17(3):3898-3904. doi: 10.3892/mmr.2017.8357. Epub 2017 Dec 27.
The pathogenesis and progression of heart failure (HF) involves multiple mechanisms, including the increased activity of the renin-angiotensin-aldosterone system, apoptosis and differential expression of microRNAs (miRNAs/miRs). Our previous study revealed an increase in miR‑31a‑5p levels in the failing hearts of a rat HF model. In the present study, whether and how miR‑31a‑5p mediates angiotensin II (AngII)‑induced apoptosis in the cardiac H9C2 cell line, was investigated using molecular biological approaches, including reverse transcription followed by quantitative polymerase chain reaction, western blotting, RNA arrays, and mutagenesis. It was demonstrated that AngII stimulation increased apoptosis and decreased miR‑31a‑5p expression, which coincided with increased tumor protein p53 (Tp53) levels. Overexpression of miR‑31a‑5p significantly suppressed the AngII‑induced apoptotic rate and caspase‑3 activity, while suppression of miR‑31a‑5p did the opposite. A total of 16 proapoptotic genes that were downregulated and 4 antiapoptotic genes that were upregulated in the miR‑31a‑5p‑overexpressed cells were identified. It was also revealed that Tp53 mRNA contained the seed sequence in its 3'‑untranslated region for miR‑31a‑5p binding. The luciferase reporter analysis showed that miR‑31a‑5p repressed the luciferase activity of the wild‑type seed sequence, but not the mutated seed sequence fused to a reporter construct. Thus, it was demonstrated that miR‑31a‑5p mediated AngII‑triggered apoptosis in myocardial cells at least partially through targeting Tp53. These findings advance the understanding of the functional interaction between miRNAs and Tp53 in the setting of cardiac diseases. Further work is required to explore whether miR‑31a‑5p can serve as a therapeutic target for HF treatment in vivo.
心力衰竭（HF）的发病机制和进展涉及多种机制，包括肾素-血管紧张素-醛固酮系统活性增加、细胞凋亡和微小 RNA（miRNA/miRs）的差异表达。我们之前的研究表明，在大鼠 HF 模型的衰竭心脏中，miR-31a-5p 的水平增加。在本研究中，使用分子生物学方法，包括逆转录定量聚合酶链反应、western blot、RNA 阵列和突变，研究了 miR-31a-5p 是否以及如何介导血管紧张素 II（AngII）诱导的心肌 H9C2 细胞系凋亡。结果表明，AngII 刺激增加了凋亡并降低了 miR-31a-5p 的表达，同时肿瘤蛋白 p53（Tp53）水平升高。miR-31a-5p 的过表达显著抑制了 AngII 诱导的细胞凋亡率和半胱天冬酶-3 活性，而抑制 miR-31a-5p 则产生相反的作用。在 miR-31a-5p 过表达的细胞中，有 16 个促凋亡基因下调，4 个抗凋亡基因上调。还揭示了 Tp53 mRNA 在其 3'-非翻译区含有与 miR-31a-5p 结合的种子序列。荧光素酶报告分析表明，miR-31a-5p 抑制了野生型种子序列融合到报告载体构建体的荧光素酶活性，但不抑制突变型种子序列的活性。因此，证明了 miR-31a-5p 通过靶向 Tp53 介导心肌细胞中 AngII 触发的凋亡。这些发现提高了对 miRNA 和 Tp53 在心脏疾病中功能相互作用的理解。需要进一步的工作来探讨 miR-31a-5p 是否可以作为体内 HF 治疗的治疗靶点。
