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.

项目摘要 为了响应心脏所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， 肥大可以帮助改善心脏功能。然而，在长期血压升高的情况下， 心率加快，体重增加过多，病理性肥大发生，最终可导致心脏 失败心肌细胞生长和萎缩的变化，随后影响生理和病理 心脏重塑由蛋白质合成的变化决定。虽然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， 已知连接这两个过程的最丰富的非编码RNA的变化： （tRNA）。除了tRNA转录所需的聚合酶III活性增加的概念之外， 对于心脏压力超负荷的反应，几乎完全不知道tRNA的改变是如何发生的。 转录、转运和定位影响蛋白质合成的位点，并最终影响心脏重塑。 考虑到心力衰竭和心肌细胞大小的先前变化导致了大多数死亡， 在美国，对于靶向病理性肿瘤中的恶性蛋白质合成的新疗法存在未满足的需求。 心脏肥大因此，这种需要可以通过鉴定新的调节转录和翻译来满足。 从一种新的以tRNA为中心的观点来控制。在这个建议中，我们将研究tRNA与 转录、运输和心脏稳态和肥大中的定位。我们已经确定了tRNA， 其被认为主要依赖于被动扩散以进行适当的定位，需要微管 在心脏中进行适当定位的网络。我们假设病理性和生理性肥大 在tRNA转录中诱导不同变化;但是这两种类型的生长都需要运动蛋白介导 tRNA沿着微管网络的主动转运，以促进蛋白质合成的必要增加， 心肌细胞生长我们将通过以下目标来检验我们的假设：（1）确定角色 微管在心肌细胞tRNA运输和定位中的作用。(2)为了表征本地化和 哺乳动物tRNA在心脏重塑过程中的表达。(3)为了鉴定促进tRNA合成的蛋白质 心肌细胞的运输。这项工作将在专家本杰明·普罗瑟博士的实验室进行 对微管、心肌细胞mRNA运输和心脏重塑的影响。圆满完成这项工作 将对确定tRNA转录、定位和运输的变化如何影响 心脏稳态和肥大，从而导致潜在的新的战略，目标心力衰竭 通过调节适应不良的蛋白质合成和受损的心脏细胞大小。