Regulation of Cardiac Gene Expression by the L-type Calcium Channel, CaV1.2.

L 型钙通道 CaV1.2 调节心脏基因表达。

基本信息

批准号：
7750969
负责人：
Robert Nathan Correll
金额：
$ 4.72万
依托单位：
CINCINNATI CHILDRENS HOSP MED CTR
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-09-07 至 2012-01-06
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7750969
关键词：
Adenoviruses Adenylate Cyclase Adrenergic Receptor American Animal Model Animals Arrhythmia Binding Biological Assay Calcineurin Cardiac Cardiac Muscle Contraction Cardiac Myocytes Caveolae Caveolins Cleaved cell Complex Coupling Development Diagnosis Disease Distal Event Exhibits Fellowship Gap Junctions Gases Gene Chips Gene Expression Gene Expression Regulation Genes Genetic Transcription Global Change Goals Heart Heart Diseases Heart Hypertrophy Heart failure Infection Injury L-Type Calcium Channels Language Mediating Mediator of activation protein Membrane Modeling Monomeric GTP-Binding Proteins NFAT Pathway Neurons Nuclear Pathway interactions Physiology Play Population Positioning Attribute Protein Dephosphorylation Protein phosphatase Proteins Publishing Regulation Reporter Role RyR2 Ryanodine Receptor Calcium Release Channel Ryanodine Receptors Sarcoplasmic Reticulum Signal Transduction Transcriptional Regulation Transgenic Animals Transgenic Mice Work combat in vivo inhibitor/antagonist mouse model overexpression pressure programs research study transcription factor voltage

项目摘要

DESCRIPTION (provided by applicant): 5.3 million Americans are diagnosed with heart failure, which is accompanied by altered Ca2+ handling and transcriptional changes leading to pathological cardiac remodeling. One such pathway, Ca2-t-regulated calcineurin/NFAT, is an essential regulator for the development of cardiac hypertrophy. The cardiac Ca2+ channel CaVI .2, which is required for excitation-contraction coupling, can also be localized to caveolar signaling microdomains that allow local Ca2+ influx through these channels to participate in signaling events and transcriptional regulation, perhaps via calcineurin/NFAT. To examine the contribution of caveolar CaV1.2 to cardiac gene regulation, in aim 1 we propose to create an adenovirus and transgenic animal expressing a chimeric RGK protein fused to a caveolin-binding motif. RGK proteins are small GTPases that completely inhibit high voltage-gated Ca2+ channels (such as CaV1.2) by direct association with the channel complex when overexpressed. Localization of the chimeric RGK protein to caveolae should allow targeted inhibition of caveolar CaVI .2 only, allowing us to observe changes in activity in Ca2+-regulated transcription factors using reporter assays, and global changes in gene expression by gene chip assay. Further experimentation will determine whether inhibition of caveolar CaV1.2 is protective against heart failure in an animal pressure overload model. Recently it was demonstrated in neurons that the cleaved C- terminus of CaVI .2 can function as a Ca2+-regulated transcription factor, however transcriptional activity of this fragment, termed CCAT, is unstudied in the heart. We propose creation of adenoviruses and transgenic animal models expressing CCAT to determine its contribution to transcriptional regulation in the heart by means of gene chip assay and further examination of CCAT roles in disease by examining whether it is protective or maladaptive in a pressure overload model of heart failure. Experiments proposed here will substantially increase our understanding of how Ca2+ signals initiate transcriptional changes important during heart failure. Lay language: Ca2+ signals are important for changes in gene expression that underlie heart disease. To examine the role of the cardiac L-type Ca2+ channel in transcription, we will construct a mouse model inhibiting this channel in signaling microdomains and determine the contribution of this channel population to gene transcription and heart failure. We similarly examine the role of the transcription factor encoded by the CaVI.2 C-terminus in disease by overexpression in a mouse model of heart failure. This work will help reveal the role of the cardiac L-type Ca2+ channel in regulation of gene expression related to disease and may suggest new translational strategies to combat heart failure.

描述（由申请人提供）：530万美国人被诊断出患有心力衰竭，并伴随着CA2+处理和转录变化的改变，导致病理心脏重塑。这样的途径是Ca2-T调节的钙调蛋白/NFAT，是心脏肥大发展的必要调节剂。激发反应耦合所需的心脏Ca2+通道Cavi .2也可以将其定位为洞穴信号传导微域，这些微区允许通过这些通道局部Ca2+涌入来参与信号传导事件和转录调节，也许是通过钙蛋白/NFAT参与转录。为了检查Caveolar Cav1.2对心脏基因调节的贡献，在AIM 1中，我们建议创建一种粘膜RGK蛋白融合到可穴蛋白结合基序的腺病毒和转基因动物。 RGK蛋白是小的GTP酶，它完全抑制高压门控Ca2+通道（例如CAV1.2），当时在过表达时与通道复合物直接缔合。将嵌合RGK蛋白定位到小窝中应允许靶向抑制Caveolar Cavi .2，从而使我们能够使用报告基因测定法观察Ca2+调节的转录因子的活性变化，以及基因ChIP Assay的基因表达的全球基因表达变化。进一步的实验将确定抑制Caveolol Cav1.2是否可以保护动物压力超负荷模型中的心力衰竭。最近在神经元中证明了Cavi .2的裂解C末端可以用作Ca2+调节的转录因子，但是该片段的转录活性（称为CCAT）在心脏中未被研究。我们建议通过基因CHIP测定法创建表达CCAT的腺病毒和转基因动物模型，以确定其对心脏转录调控的贡献，并通过检查心脏失败压力超负荷模型中的保护性还是适应性，通过检查疾病中的CCAT角色。此处提出的实验将大大提高我们对CA2+信号在心力衰竭过程中如何启动转录变化的理解。外行语言：CA2+信号对于基因表达的变化很重要，而基因表达是心脏病基础的基因表达。为了检查心脏L型Ca2+通道在转录中的作用，我们将构建一个小鼠模型，该模型抑制该通道在信号微区中，并确定该通道群体对基因转录和心力衰竭的贡献。我们类似地研究了由Cavi.2 C末端编码的转录因子在疾病中通过过表达在心力衰竭模型中的过表达的作用。这项工作将有助于揭示心脏L型Ca2+通道在调节与疾病有关的基因表达中的作用，并可能提出新的翻译策略来打击心力衰竭。