Graduate Institute of Basic Medical Science, China Medical University, Taichung 404, Taiwan.
Division of Cardiovascular Surgery, Department of Surgery, Taichung Armed Force General Hospital, Taichung 411, Taiwan.
Int J Mol Sci. 2019 Sep 2;20(17):4288. doi: 10.3390/ijms20174288.
Cardiovascular diseases have a high prevalence worldwide and constitute the leading causes of mortality. Recently, malfunctioning of β-catenin signaling has been addressed in hypertensive heart condition. Ang-II is an important mediator of cardiovascular remodeling processes which not only regulates blood pressure but also leads to pathological cardiac changes. However, the contribution of Ang-II/β-catenin axis in hypertrophied hearts is ill-defined. Employing in vitro H9c2 cells and in vivo spontaneously hypertensive rats (SHR) cardiac tissue samples, western blot analysis, luciferase assays, nuclear-cytosolic protein extracts, and immunoprecipitation assays, we found that under hypertensive condition β-catenin gets abnormally induced that co-activated LEF1 and lead to cardiac hypertrophy changes by up-regulating the IGF-IIR signaling pathway. We identified putative LEF1 consensus binding site on IGF-IIR promoter that could be regulated by β-catenin/LEF1 which in turn modulate the expression of cardiac hypertrophy agents. This study suggested that suppression of β-catenin expression under hypertensive condition could be exploited as a clinical strategy for cardiac pathological remodeling processes.
心血管疾病在全球范围内高发,是导致死亡的主要原因。最近,β-连环蛋白信号通路的功能障碍已被确定为高血压性心脏病变的原因之一。血管紧张素 II(Ang-II)是心血管重塑过程的重要介质,不仅可以调节血压,还会导致病理性的心脏改变。然而,Ang-II/β-连环蛋白轴在心肌肥厚中的作用尚未明确。通过体外 H9c2 细胞和体内自发性高血压大鼠(SHR)心脏组织样本的 Western blot 分析、荧光素酶报告基因检测、核质蛋白提取物和免疫沉淀实验,我们发现高血压条件下β-连环蛋白异常诱导,与 LEF1 协同激活,通过上调 IGF-IIR 信号通路导致心肌肥厚改变。我们在 IGF-IIR 启动子上鉴定到了可能的 LEF1 结合位点,该位点受β-连环蛋白/LEF1 调控,进而调节心肌肥厚相关因子的表达。本研究表明,在高血压条件下抑制β-连环蛋白的表达可能成为治疗心脏病理性重塑的一种临床策略。