Genes and miRNAs controlled by ORAI3 in cardiovascular remodeling

 描述(由申请人提供)不利的心血管重构在老年患者中尤其普遍，导致生活质量低下和毁灭性的后果。为了应对各种生理和病理压力，心脏和血管系统会随着形状和功能的改变而重塑，逐渐导致不利的心血管结果1。在细胞水平上，这种病理重塑是由细胞内信号通路的异常启动和维持的，尤其是那些由钙(Ca~(2+))2控制的信号通路。我们两个实验室最近的研究发现了心血管心肌细胞(即心肌细胞、CMS和血管平滑肌细胞)3-5钙离子进入的新来源。这一来源由基质相互作用分子1(STIM1)组成的复合体控制，STIM1是一种主要在内质网(ER)膜上表达的钙离子感受器，它与新的钙离子选择性质膜(PM)通道家族Orai家族(Orai1至Orai3)相互作用并激活。STIM1/Orai1-3信号模式可以形成：i)由内质网钙离子储存耗竭(Orai1同聚体)激活的质膜钙离子通道，称为钙释放激活的钙通道(CRAC)；或ii)由花生四烯酸代谢产物白三烯C4(LTC4)激活并由Orai1和Orai3的异源多聚体(LRC，LTC4调节的钙离子)3-7激活的非储存非依赖性钙通道。在心脏和血管疾病的不同细胞和动物模型中，我们已经证明了STIM/Orai介导的钙信号的出现，该信号特异性地耦合到基因转录，并支持与心脏和血管重构相关的表型变化(分别是CM生长-心肌肥厚和VSMC增殖-血管狭窄)3-5。这种局部钙源的靶向操作防止了不利的心脏和血管重构，从而提供了新的治疗角度3-5。该项目的目标是表征由心血管系统中STIM1/ORAI复合体的不同元件具体控制的分子过程。我们最近的数据表明，与Orai1一样，Orai3是病理性心血管细胞中STIM1依赖的钙离子选择性电流的关键组成部分，Orai3是哺乳动物独有的。因此，我们假设Orai3通道更具特异性地调节心血管重塑过程中激活的关键通路和基因网络，以促进细胞的生长、增殖和存活。我们建议比较STIM1和Orai3组织特异性基因敲除小鼠和野生型小鼠分离的心血管肌细胞(即心肌细胞和动脉平滑肌细胞)在正常和病理条件下心脏和血管重塑的转录特征。总之，这些探索性结果将支持Orai3靶向治疗与年龄相关的心血管重塑。

 DESCRIPTION (provided by applicant) Adverse cardiovascular remodeling is particularly prevalent in elderly patients, resulting in poor quality of life and devastating consequences. In response to various physiological and pathological stressors, the cardiac and vascular systems remodel with changes in shape and function that progressively lead to adverse cardiovascular outcomes1. At the cellular level, this pathological remodeling is initiated and sustained by abnormalities in intracellular signaling pathways especially those controlled by calcium (Ca2+)2. Recent studies from both our laboratories have identified a new source of Ca2+ entry in cardiovascular myocytes (i.e., cardiac myocytes; CMs and vascular smooth muscle cells; VSMCs)3-5. This source is controlled by a complex composed of STromal Interaction Molecule 1 (STIM1), a Ca2+ sensor mainly expressed at the endoplasmic reticulum (ER) membrane, which interacts with and activates a new family of Ca2+ selective plasma membrane (PM) channels, the Orai family (Orai1 through 3). The STIM1/Orai1-3 signaling paradigm can either form: i) PM Ca2+ channels activated by ER Ca2+ store depletion (Orai1 homomers) termed Ca2+ release-activated Ca2+ (CRAC) channels, or ii) store-independent Ca2+ channels activated from the cytosolic side by the arachidonate metabolite, leukotrieneC4 (LTC4) and mediated by heteromultimers of Orai1 and Orai3 (named LRC for LTC4-regulated Ca2+)3-7. In different cellular and animal models of cardiac and vascular disorders, we have demonstrated the emergence of the STIM/Orai-mediated Ca2+ signaling that specifically couples to gene transcription and underlies phenotypic changes associated with cardiac and vascular remodeling (i.e. CM growth - cardiac hypertrophy and VSMC proliferation - vascular stenosis respectively)3-5. The targeted manipulation of this local calcium source prevents adverse cardiac and vascular remodeling thus offering new therapeutic perspectives3-5. The goal of this project is the characterization of the molecular processes that are specifically controlled by the different elements of the STIM1/Orai complex in the cardiovascular system. Our recent data indicate that along with Orai1, Orai3, which is exclusive to mammals, is a key component of the STIM1-dependent store- independent Ca2+ selective currents that emerge in pathological cardiovascular myocytes. We thus hypothesize that Orai3 channels more specifically regulate key pathways and gene networks that are activated during cardiovascular remodeling in order to promote cell growth, proliferation and survival. We propose to compare the transcriptional signature of isolated cardiovascular myocytes (i.e., cardiac myocytes and arterial smooth muscle cells) from Stim1 and Orai3 tissue-specific knockout mice and from wild-type mice under normal and pathological conditions of cardiac and vessel remodeling. Together, these exploratory results will support Orai3 targeting in age-related cardiovascular remodeling.