Microtubule-mediated tRNA localization in cardiac homeostasis and hypertrophy

微管介导的 tRNA 在心脏稳态和肥大中的定位

• 批准号: 10750674
• 负责人: Jennifer Morgan Petrosino
• 金额: $ 6.91万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-07 至 2025-08-06
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10750674
• 关键词: Active Biological Transport; Adrenergic Agents; Atrophic; Belief; Biological Assay; Biology; CCRL2 gene; Cardiac; Cardiac Myocytes; Cardiovascular Diseases; Cardiovascular system; Cell Separation; Cell Size; Cells; Cessation of life; Chronic stress; Complement; Complex; Contractile Proteins; Cytoskeleton; Data; Defect; Dependence; Diffusion; Exercise; Functional disorder; Genetic Transcription; Growth; Heart; Heart Diseases; Heart Hypertrophy; Heart Rate; Heart failure; Homeostasis; Human; Hypertrophy; Immunofluorescence Immunologic; Immunoprecipitation; Impairment; In Vitro; Injections; Intervention; Kinesin; Kinetics; Label; Laboratories; Length; Link; Lower Organism; Malignant - descriptor; Mass Spectrum Analysis; Mediating; Messenger RNA; Microscopy; Microtubules; Modeling; Molecular; Motor; Muscle Cells; Mutation; Nocodazole; Nuclear; Pathologic; Phenylephrine; Physiological; Polymerase; Process; Property; Protein Biosynthesis; Proteins; RNA Transport; Rattus; Regulation; Research; Resolution; Role; Site; Stains; Stimulus; Structure; Surgical Models; Technology; Testing; Thick; Transfer RNA; Translations; Transport Process; United States; Untranslated RNA; Visualization; Work; aorta constriction; blood pressure elevation; cell fixing; cell motility; excessive weight gain; functional improvement; heart function; hemodynamics; improved; in vivo; knock-down; new therapeutic target; novel; novel therapeutics; pharmacologic; pressure; reconstitution; repaired; response; single molecule; spatiotemporal; superresolution microscopy; tool; trafficking

PROJECT SUMMARY In response to hemodynamic demands faced by the heart, cardiomyocytes adapt and remodel primarily through changes in myocyte thickness or length. In conditions like cardiovascular exercise, changes in physiological hypertrophy can aid in improving cardiac function. However, in conditions of prolonged elevated blood pressure, heart rate, and excessive weight gain, pathological hypertrophy occurs and ultimately can contribute to heart failure. Changes in cardiomyocyte growth and atrophy that subsequently impact physiological and pathological cardiac remodeling are dictated by changes in protein synthesis. And while there is significant progress in understanding the transcriptional and translational changes that mediate maladaptive cardiac remodeling, little is known about the changes in the most abundant noncoding RNAs that link these two processes: transfer RNAs (tRNA). Outside of the notion that Polymerase III activity, which is required for tRNA transcription, increases in response to cardiac pressure overload, almost completely nothing is known about how alterations in tRNA transcription, transport, and localization impact sites of protein synthesis and, ultimately, cardiac remodeling. Considering that heart failure and the preceding changes in myocyte size contribute to the majority of deaths in the United States, there is an unmet need for new therapies that target malignant protein synthesis in pathological cardiac hypertrophy. Hence, this need may be met by identifying new regulating transcription and translational control from a novel tRNA-centric view. In this proposal, we will examine the relationship between tRNA transcription, transport, and localization in cardiac homeostasis and hypertrophy. We have identified that tRNAs, which are believed to primarily rely on passive diffusion for appropriate localization, require the microtubule network for proper localization in the heart. We hypothesize that pathological and physiological hypertrophy induce different changes in tRNA transcription; but that both types of growth require motor protein-mediated active transport of tRNAs along the microtubule network to facilitate necessary increases in protein synthesis for cardiomyocyte growth. We will test our hypothesis by carrying out the following aims: (1) To determine the role of microtubules in tRNA trafficking and localization in the cardiomyocyte. (2) To characterize the localization and expression of mammalian tRNAs during cardiac remodeling. (3) To identify the proteins that facilitate tRNA trafficking in cardiomyocytes. This work will be carried out in the laboratory of Dr. Benjamin Prosser, an expert on microtubules, cardiomyocyte mRNA trafficking, and cardiac remodeling. Successful completion of this work will have the positive impact of defining how changes in tRNA transcription, localization, and trafficking impact cardiac homeostasis and hypertrophy and thus result in the potential new strategies that target heart failure through the regulation of maladaptive protein synthesis and compromised cardiac cell size.

项目概要 为了响应心脏面临的血流动力学需求，心肌细胞主要通过以下方式进行适应和重塑： 肌细胞厚度或长度的变化。在心血管运动等条件下，生理变化 肥厚有助于改善心脏功能。然而，在血压长期升高的情况下， 心率加快，体重过度增加，发生病理性肥大，最终会导致心脏病 失败。心肌细胞生长和萎缩的变化随后影响生理和病理 心脏重塑是由蛋白质合成的变化决定的。尽管在这方面取得了重大进展 了解介导适应不良心脏重塑的转录和翻译变化，很少 已知连接这两个过程的最丰富的非编码 RNA 的变化：转移 RNA （tRNA）。除了 tRNA 转录所需的聚合酶 III 活性在 对于心脏压力超负荷的反应，几乎完全不知道 tRNA 的变化是如何发生的 转录、运输和定位影响蛋白质合成的位点，并最终影响心脏重塑。 考虑到心力衰竭和先前的肌细胞大小变化导致了大​​多数死亡 在美国，针对病理学中恶性蛋白质合成的新疗法的需求尚未得到满足。 心脏肥大。因此，这种需求可以通过识别新的转录和翻译调节因子来满足。 从新的以 tRNA 为中心的观点进行控制。在本提案中，我们将研究 tRNA 之间的关系 心脏稳态和肥大中的转录、运输和定位。我们已经确定 tRNA， 据信主要依靠被动扩散来进行适当的定位，需要微管 网络在心脏中的正确定位。我们假设病理性和生理性肥大 诱导 tRNA 转录的不同变化；但这两种类型的生长都需要运动蛋白介导 tRNA 沿着微管网络主动运输，以促进蛋白质合成的必要增加 心肌细胞生长。我们将通过实现以下目标来检验我们的假设：（1）确定角色 微管在心肌细胞中 tRNA 运输和定位中的作用。 (2) 定位和表征 哺乳动物 tRNA 在心脏重塑过程中的表达。 (3) 鉴定促进tRNA的蛋白质 心肌细胞的贩运。这项工作将在专家Benjamin Prosser博士的实验室进行 微管、心肌细胞 mRNA 运输和心脏重塑。顺利完成本次工作 将对定义 tRNA 转录、定位和运输的变化如何影响产生积极影响 心脏稳态和肥厚，从而产生针对心力衰竭的潜在新策略 通过调节适应不良的蛋白质合成和受损的心肌细胞大小。