"Connexin-Dependent Transcriptomic Networks in Controlling the Heart Rhythm"

“控制心律的连接蛋白依赖性转录组网络”

• 批准号: 7584374
• 负责人: Dumitru Andrei Iacobas
• 金额: $ 41.5万
• 依托单位: ALBERT EINSTEIN COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7584374
• 关键词: Acute; Address; Adult; Affect; Age; Algorithms; Anti-Arrhythmia Agents; Arrhythmia; Biological; Candidate Disease Gene; Cardiac; Cardiac Myocytes; Cardiology; Cause of Death; Cell Line; Cells; Chronic; Connexin 43; Connexins; Coupling; Data; Defect; Dependence; Development; Disease; Down-Regulation; Etiology; Evolution; Exhibits; Female; Gap Junctions; Gender; Gene Expression; Gene Expression Profile; Gene Expression Profiling; Genes; Goals; Hearing; Heart; Heart Atrium; Heart Diseases; Internet; Ions; Life; Link; Literature; Methods; Mission; Modeling; Mus; Muscle Cells; Mutation; Pathway interactions; Phenotype; Principal Component Analysis; Recovery; Regulation; Regulator Genes; Reporting; Resistance; Role; Sampling; Signaling Molecule; Small Interfering RNA; Testing; Time; Tissues; Up-Regulation; Ventricular; Work; analytical tool; base; gap junction channel; genome-wide; heart rhythm; insight; interest; knock-down; male; novel therapeutics; overexpression; public health relevance; research study; transcriptomics; virtual

DESCRIPTION (provided by applicant): Extensive literature has reported altered expression and/or mutation of the primary gap junction proteins (connexins, Cx) that couple myocytes in ventricles (Cx43) and atria (Cx40) among major causes of cardiac arrhythmias. We have found that numerous genes controlling a vast number of functional pathways are regulated in Cx43 null tissues and these regulations are accurately predicted from coordination with Cx43 gene (Gja1) in wildtypes. These findings suggest an additional etiology of the disease that is related to connexins but not necessarily to the intercellular coupling they provide. Our working hypothesis is that the genes encoding the heart rhythm determinants (HRD) are interconnected in connexin-dependent and connexin-independent transcriptomic networks whose topologies may change during development and exhibit slight differences between the two genders. Such regulatory networks, where linkage partners are rearranged and strength modified in disease, may explain downstream and parallel "ripples" of phenotypic change. We plan to verify this hypothesis, and build and characterize the atrial and ventricular webs of genes encoding hear rhythm determinants. In addition, we shall identify and quantify the connexin-dependent regulatory networks within these webs. Of particular interest will be to identify the gene pairs with strikingly similar or opposite coordination profiles because up-regulation of a similar one or down-regulation of an opposed are expected to compensate for the deficient expression of the counterpart (as "transcriptomic see-saws"). For these, we shall profile the atrial and ventricular transcriptomes of wildtype, Cx40 null and Cx43 conditional knockdown male and female mice at E19, 1, 2 and 4 weeks of their early life. The expression data will be also used to determine the expression variability and intercoordination of all quantifiable unigenes and study the age and gender dependence of the HRD gene webs. We have developed the Principal Gene Analysis by which to identify the heart rhythm determinants (HRD), build and characterize the webs of their encoding genes. The "see-saw" model will be tested by comparing the transcriptomes of cultured cardiomyocytes in which expression of either Cx43 or of certain positive "see-saw" partners are knocked-down through siRNA treatment. Thus, this study is expected to reveal new organizational principles of the heart transcriptome and the role of gap junction genes in this organization, with the long-term goal to open novel therapeutic horizons in the treatment of arrhythmia. PUBLIC HEALTH RELEVANCE: Gap junctions between cardiac muscle cells provide the channels for intercellular current flow that assures propagation of contraction throughout the heart. Increasing evidence attributes numerous cardiac arrhythmias to altered gap junctions and the proteins of which they are composed. We hypothesize that this role of gap junction gene expression is due in part to linkage to expression of other genes that affect the cardiac rhythm, and we propose to use gene expression profiling from microarrays to achieve a comprehensive understanding of arrhythmia and to generate hypotheses testable by more focused methods. We plan to profile the gene expressions in atria and ventricles of male and female wildtype mice and mice lacking the main cardiac gap junction proteins at four time- points during evolution to the adult state to identify and quantify on a genome-wide scale the connexin- related transcriptomic determinants of arrhythmia, analyzing their gender dependence and maturation. A major contribution will consist in identifying candidate genes whose manipulation might restore the normal cardiac rhythm based on their similar or opposed expression coordination with cardiac connexins in the sampled transcriptome and to that of other genes whose alteration generates arrhythmia. The study will reveal new organizational principles of the heart transcriptome, with the long- term goal to open novel therapeutic horizons in the treatment of arrhythmia. Our project has the unique feature of describing and quantifying the Cx40- and Cx43-dependent Gene Regulatory Networks of the heart rhythm, with the long term goal to open novel therapeutic horizons in cardiology.

描述(由申请人提供)：大量文献报道了主要的缝隙连接蛋白(连接蛋白，Cx)的表达和/或突变，该蛋白连接心室(Cx43)和心房(Cx40)的肌细胞，是导致心律失常的主要原因之一。我们已经发现，在Cx43缺失的组织中，许多控制大量功能通路的基因都受到调控，并且这些调控可以通过与野生型Cx43基因(Gja1)的协调准确地预测出来。这些发现提示了这种疾病的另一个病因，它与连接蛋白有关，但不一定与它们提供的细胞间偶联有关。我们的工作假设是，编码心率决定因素(HRD)的基因在连接蛋白依赖和连接蛋白非依赖的转录网络中相互连接，这些网络的拓扑结构在发育过程中可能会改变，并在两性之间显示出微小的差异。这样的调控网络，其中链接伙伴被重新排列，强度在疾病中被改变，可能解释了表型变化的下游和平行的“涟漪”。我们计划验证这一假设，并构建和表征心跳节律决定因素编码基因的房室网。此外，我们将识别和量化这些网络中依赖连接蛋白的调控网络。特别令人感兴趣的是确定具有惊人相似或相反配位特征的基因对，因为类似基因的上调或相反基因的下调有望弥补对应物的表达缺陷(如“转录拉锯法”)。为此，我们将描述野生型、Cx40缺失和Cx43条件性基因敲除的雄性和雌性小鼠在E19、1、2和4周早期的心房和心室转录。表达数据还将用于确定所有可量化的单基因的表达变异性和相互协调性，并研究HRD基因网络的年龄和性别相关性。我们已经开发了主基因分析，通过它来识别心率决定因素(HRD)，建立和表征其编码基因的网络。“拉锯法”模型将通过比较培养的心肌细胞的转录本进行测试，在培养的心肌细胞中，Cx43的表达或某些阳性的“拉锯法”伙伴通过siRNA处理而被下调。因此，这项研究有望揭示心脏转录组的新组织原理和缝隙连接基因在这一组织中的作用，长期目标是在治疗心律失常方面开辟新的治疗视野。公共卫生相关性：心肌细胞之间的缝隙连接为细胞间电流流动提供通道，从而确保收缩在整个心脏中的传播。越来越多的证据将许多心律失常归因于缝隙连接和构成缝隙连接的蛋白质的改变。我们假设缝隙连接基因表达的这种作用部分是由于与其他影响心律的基因表达的连锁，我们建议使用微阵列的基因表达谱来实现对心律失常的全面理解，并产生可通过更有针对性的方法验证的假设。我们计划对雄性和雌性野生型小鼠和缺乏主要心脏缝隙连接蛋白的小鼠在向成体状态进化的四个时间点的心房和心室中的基因表达进行分析，以在全基因组水平上识别和量化与连接蛋白相关的心律失常决定因素，分析它们的性别依赖性和成熟性。一个主要的贡献将在于识别候选基因，基于它们与采样转录组中的心脏连接蛋白相似或相反的表达协调，以及与其他引起心律失常的基因的改变，这些候选基因的操作可以恢复正常的心律失常。这项研究将揭示心脏转录组的新组织原则，长期目标是在治疗心律失常方面开辟新的治疗视野。我们的项目具有描述和量化依赖于Cx40和Cx43的心律基因调控网络的独特功能，长期目标是打开心脏病学的新治疗视野。