Na Jingtao, Jin Haifeng, Wang Xin, Huang Kan, Sun Shuang, Li Qiang, Zhang Wenting
Department of Cardiology, The Third Affiliated Hospital of Qiqihar Medical University, No. 27, Taishun Street, Tiefeng District, Qiqihar, 161099, Heilongjiang Province, P.R. China.
Department of Anatomy, Qiqihar Medical University, Qiqihar, 161006, P.R. China.
Cell Biosci. 2021 Feb 6;11(1):31. doi: 10.1186/s13578-020-00523-y.
Heart failure (HF) is a clinical syndrome characterized by left ventricular dysfunction or elevated intracardiac pressures. Research supports that microRNAs (miRs) participate in HF by regulating targeted genes. Hence, the current study set out to study the role of HDAC3-medaited miR-18a in HF by targeting ADRB3.
Firstly, HF mouse models were established by ligation of the left coronary artery at the lower edge of the left atrial appendage, and HF cell models were generated in the cardiomyocytes, followed by ectopic expression and silencing experiments. Numerous parameters including left ventricular posterior wall dimension (LVPWD), interventricular septal dimension (IVSD), left ventricular end diastolic diameter (LVEDD), left ventricular end systolic diameter (LVESD), left ventricular ejection fraction (LVEF), left ventricular fractional shortening (LVFS), left ventricular systolic pressure (LVSP), left ventricular end diastolic pressure (LEVDP), heart rate (HR), left ventricular pressure rise rate (+ dp/dt) and left ventricular pressure drop rate (-dp/dt) were measured in the mice. In addition, apoptosis in the mice was detected by means of TUNEL staining, while RT-qPCR and Western blot analysis were performed to detect miR-18a, HDAC3, ADRB3, cMyb, MMP-9, Collagen 1 and TGF-β1 expression patterns. Dual luciferase reporter assay validated the targeting relationship between ADRB3 and miR-18a. Cardiomyocyte apoptosis was determined by means of flow cytometry.
HDAC3 and ADRB3 were up-regulated and miR-18a was down-regulated in HF mice and cardiomyocytes. In addition, HDAC3 could reduce the miR-18a expression, and ADRB3 was negatively-targeted by miR-18a. After down-regulation of HDAC3 or ADRB3 or over-expression of miR-18a, IVSD, LVEDD, LVESD and LEVDP were found to be decreased but LVPWD, LVEF, LVFS, LVSP, + dp/dt, and -dp/dt were all increased in the HF mice, whereas fibrosis, hypertrophy and apoptosis of HF cardiomyocytes were declined.
Collectively, our findings indicate that HDAC3 silencing confers protection against HF by inhibiting miR-18a-targeted ADRB3.
心力衰竭（HF）是一种以左心室功能障碍或心腔内压力升高为特征的临床综合征。研究支持微小RNA（miRs）通过调控靶基因参与心力衰竭。因此，本研究旨在通过靶向β3肾上腺素能受体（ADRB3）研究组蛋白去乙酰化酶3（HDAC3）介导的miR-18a在心力衰竭中的作用。
首先，通过结扎左心耳下缘的左冠状动脉建立心力衰竭小鼠模型，并在心肌细胞中建立心力衰竭细胞模型，随后进行异位表达和沉默实验。测量小鼠的多个参数，包括左心室后壁厚度（LVPWD）、室间隔厚度（IVSD）、左心室舒张末期内径（LVEDD）、左心室收缩末期内径（LVESD）、左心室射血分数（LVEF）、左心室短轴缩短率（LVFS）、左心室收缩压（LVSP）、左心室舒张末期压力（LEVDP）、心率（HR）、左心室压力上升速率（+dp/dt）和左心室压力下降速率（-dp/dt）。此外，通过TUNEL染色检测小鼠的细胞凋亡，同时进行逆转录-定量聚合酶链反应（RT-qPCR）和蛋白质免疫印迹分析以检测miR-18a、HDAC3、ADRB3、c-Myb、基质金属蛋白酶-9（MMP-9）、胶原蛋白-1和转化生长因子-β1（TGF-β1）的表达模式。双荧光素酶报告基因实验验证了ADRB3与miR-18a之间的靶向关系。通过流式细胞术测定心肌细胞凋亡。
在心力衰竭小鼠和心肌细胞中，HDAC3和ADRB3上调，而miR-18a下调。此外，HDAC3可降低miR-18a的表达，且ADRB3是miR-18a的负向靶标。下调HDAC3或ADRB3或过表达miR-18a后，发现心力衰竭小鼠的IVSD、LVEDD、LVESD和LEVDP降低，但LVPWD、LVEF、LVFS、LVSP、+dp/dt和-dp/dt均升高，而心力衰竭心肌细胞的纤维化、肥大和凋亡减少。
总体而言，我们的研究结果表明，沉默HDAC3通过抑制miR-18a靶向的ADRB3对心力衰竭具有保护作用。
