Translation initiation in cardiac intercellular communication and stress-induced remodeling

心脏细胞间通讯和应激诱导重塑中的翻译起始

基本信息

批准号：
9384399
负责人：
James William Smyth
金额：
$ 39.37万
依托单位：
VIRGINIA POLYTECHNIC INST AND ST UNIV
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-07-01 至 2022-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9384399
关键词：
5&apos Untranslated Regions Animals Arrhythmia Attention Cardiac Cardiac Myocytes Cardiovascular Diseases Cause of Death Cell model Cells Code Communication Connexin 43 Coupling Data Defect Elements Event Gap Junctions Genes Genetic Transcription Genetic Translation Goals Heart Heart Diseases Heart Hypertrophy Human Hypertrophy Hypoxia Intercalated disc Internal Ribosome Entry Site Ion Channel Ischemia Isoproterenol Knowledge Laboratories Lead Maintenance Messenger RNA Mus Myocardial Ischemia Myocardium Pathologic Pathway interactions Process Protein Biosynthesis Protein Isoforms Proteins Proteome RNA-Binding Proteins Recruitment Activity Regulation Regulatory Element Regulatory Pathway Research Ribosomes Role Slice Stress Structure System Testing Therapeutic Tissues Trans-Activators Transcript Transforming Growth Factor beta Translating Translation Initiation Translational Regulation Translations United States Viral Work base biological adaptation to stress epithelial to mesenchymal transition heart cell insight intercellular communication polypeptide prevent programs sudden cardiac death

项目摘要

SUMMARY Reductions in intercellular communication occur in almost all forms of heart disease and lead to the arrhythmias of sudden cardiac death. The most intensely studied component of the intercalated disc of the working cardiomyocyte is the connexin 43 (Cx43) gap junction. The Cx43 gene, GJA1, encodes a polycistronic mRNA that undergoes internal translation events yielding truncated polypeptides capable of modulating gap junction formation and subject to altered regulation during stress such as ischemia and hypertrophy. Such internal translation within protein coding sequences of mammalian mRNAs has only recently been identified, and a substantial gap in the knowledge exists as to how this process is regulated by the cell and if manipulation of upstream regulatory pathways and associated proteins can be harnessed therapeutically to restore normal intercellular communication in diseased hearts. The objective of this application is to provide mechanistic insight into the role of altered translation initiation in pathological Cx43 gap junction regulation and remodeling. This work is significant because it will identify altered translation initiation as a common stress response in the heart and provide fundamental understanding of regulation of electrical communication through rapid alteration of the proteome by ribosomal initiation. Our central hypothesis is that dynamic regulation of the translational landscape of the cell governs intercellular communication, is vital in maintenance of proper cardiac electrical coupling, and is altered by the integrated stress response during pathological remodeling of the heart. We will test our central hypothesis with the following specific aims: AIM 1: Determine the role of altered translation initiation in gap junction regulation. The working hypothesis for this aim is that a cellular program exists at the level of translation initiation which regulates transition from a `junctional' to a `non- junctional' state. AIM 2: Delineate the regulatory elements of GJA1 mRNA critical for internal translation initiation. The working hypothesis for this aim is that GJA1 mRNA harbors sequence- and structure-based elements necessary for internal translation to occur via recruitment of specific RNA binding proteins. AIM 3: Test if modulation of translation initiation protects against pathological cardiac remodeling. Our working hypothesis for this aim is that the integrated stress response (ISR) alters translation initiation of GJA1, reducing GJA1-20k expression and limiting gap junction formation in stressed and hypertrophic myocardium. The work outlined in this proposal is significant because it will (i) provide mechanistic insight into the role of internal translation in regulation of gap junctions and intercellular communication during stress (ii) determine how this relates to pathological remodeling in hypertrophic and ischemic hearts, and (iii) test if modulation of internal translation is a viable therapeutic strategy for human heart disease.

概括细胞间通讯的减少几乎发生在所有形式的心脏病中，并导致心源性猝死的心律失常。闰盘中研究最深入的部分工作心肌细胞是连接蛋白 43 (Cx43) 间隙连接。 Cx43 基因 GJA1 编码多顺反子经历内部翻译事件的 mRNA 产生能够调节间隙的截短多肽连接的形成，并在缺血和肥大等应激过程中受到调节的改变。这样的哺乳动物 mRNA 的蛋白质编码序列内的内部翻译直到最近才被鉴定，关于细胞如何调节这一过程以及是否上游调控途径和相关蛋白质的操纵可以在治疗上利用恢复患病心脏的正常细胞间通讯。该应用程序的目的是提供改变翻译起始在病理性 Cx43 间隙连接调节中的作用的机制洞察重塑。这项工作意义重大，因为它将把改变的翻译起始识别为一种常见的压力心脏反应并通过以下方式提供对电通讯调节的基本理解通过核糖体起始快速改变蛋白质组。我们的中心假设是动态调节细胞的翻译景观控制着细胞间的通讯，对于维持正常的细胞间通讯至关重要心脏电耦合，并且在病理重塑过程中被综合应激反应改变心脏。我们将通过以下具体目标来检验我们的中心假设：目标 1：确定改变间隙连接调节中的翻译起始。该目标的工作假设是细胞程序存在于翻译启动的层面，它调节从“连接”到“非”的转换。结'状态。目标 2：描述对内部翻译至关重要的 GJA1 mRNA 调控元件引发。该目标的工作假设是 GJA1 mRNA 具有基于序列和结构的通过招募特定的 RNA 结合蛋白进行内部翻译所必需的元件。目标 3：测试翻译起始的调节是否可以防止病理性心脏重塑。我们的这一目标的工作假设是综合应激反应（ISR）改变了 GJA1 的翻译起始，减少 GJA1-20k 表达并限制应激和肥厚心肌中间隙连接的形成。该提案中概述的工作意义重大，因为它将 (i) 提供对该角色的机械洞察应激期间间隙连接和细胞间通讯调节中的内部翻译 (ii) 确定这与肥厚和缺血心脏的病理重塑有何关系，以及（iii）测试是否调节内翻译是人类心脏病的一种可行的治疗策略。