Pan Liming, Sheng Mengting, Huang Zirui, Zhu Zhilin, Xu Chunli, Teng Lin, He Ling, Gu Chen, Yi Cai, Li Junming
Department of Cardiology, the People's Hospital of Three Gorges University/the First People's Hospital of Yichang, Yichang, China.
Department of Intensive Care Unit(ICU), the People's Hospital of Three Gorges University/the First People's Hospital of Yichang, Yichang, China.
PLoS One. 2017 Oct 24;12(10):e0186635. doi: 10.1371/journal.pone.0186635. eCollection 2017.
This study aimed to investigated the effect and mechanism of zinc-finger protein 418 (ZNF418) on cardiac hypertrophy caused by aortic banding (AB), phenylephrine (PE) or angiotensin II (Ang II) in vivo and in vitro.
The expression of ZNF418 in hearts of patients with dilated cardiomyopathy (DCM) or hypertrophic cardiomyopathy (HCM) and AB-induced cardiac hypertrophy mice, as well as in Ang II- or PE-induced hypertrophic primary cardiomyocytes was detected by western blotting. Then, the expression of ZNF418 was up-regulated or down-regulated in AB-induced cardiac hypertrophy mice and Ang II -induced hypertrophic primary cardiomyocytes. The hypertrophic responses and fibrosis were evaluated by echocardiography and histological analysis. The mRNA levels of hypertrophy markers and fibrotic markers were detected by RT-qPCR. Furthermore, the phosphorylation and total levels of c-Jun were measured by western blotting.
ZNF418 was markedly down-regulated in hearts of cardiac hypertrophy and hypertrophic primary cardiomyocytes. Down-regulated ZNF418 exacerbated the myocyte size and fibrosis, moreover increased the mRNA levels of ANP, BNP, β-MHC, MCIP1.4, collagen 1a, collagen III, MMP-2 and fibronection in hearts of AB-treated ZNF418 knockout mice or Ang II-treated cardiomyocytes with AdshZNF418. Conversely, these hypertrophic responses were reduced in the ZNF418 transgenic (TG) mice treated by AB and the AdZNF418-transfected primary cardiomyocytes treated by Ang II. Additionally, the deficiency of ZNF418 enhanced the phosphorylation level of c-jun, and overexpression of ZNF418 suppressed the phosphorylation level of c-jun in vivo and in vitro.
ZNF418 maybe attenuate hypertrophic responses by inhibiting the activity of c-jun/AP-1.
本研究旨在探讨锌指蛋白418（ZNF418）在体内外对主动脉缩窄（AB）、去甲肾上腺素（PE）或血管紧张素II（Ang II）所致心肌肥大的影响及其机制。
采用蛋白质免疫印迹法检测扩张型心肌病（DCM）或肥厚型心肌病（HCM）患者心脏、AB诱导的心肌肥大小鼠心脏以及Ang II或PE诱导的原代肥大心肌细胞中ZNF418的表达。然后，在AB诱导的心肌肥大小鼠和Ang II诱导的原代肥大心肌细胞中上调或下调ZNF418的表达。通过超声心动图和组织学分析评估肥大反应和纤维化。采用逆转录定量聚合酶链反应（RT-qPCR）检测肥大标志物和纤维化标志物的mRNA水平。此外，通过蛋白质免疫印迹法检测c-Jun的磷酸化水平和总水平。
在心肌肥大心脏和原代肥大心肌细胞中，ZNF418明显下调。下调ZNF418会加剧心肌细胞大小和纤维化，此外还会增加AB处理的ZNF418基因敲除小鼠心脏或AdshZNF418处理的Ang II心肌细胞中ANP、BNP、β-MHC、MCIP1.4、胶原蛋白1a、胶原蛋白III、基质金属蛋白酶-2和纤连蛋白的mRNA水平。相反，在AB处理的ZNF418转基因（TG）小鼠和Ang II处理的AdZNF418转染原代心肌细胞中，这些肥大反应减弱。此外，ZNF418缺乏会增强c-jun的磷酸化水平，而ZNF418过表达在体内外均会抑制c-jun的磷酸化水平。
ZNF418可能通过抑制c-jun/AP-1的活性来减轻肥大反应。
