Non-cardiomyocyte miR-34a Mediates Susceptibility to Right Heart Failure

非心肌细胞 miR-34a 介导右心衰竭的易感性

• 批准号: 8870024
• 负责人: Sushma Reddy
• 金额: $ 13.17万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-03-05 至 2020-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8870024
• 关键词: Angiotensin-Converting Enzyme Inhibitors; Antioxidants; Attenuated; Binding; Biological Markers; Biology; Cardiac; Cardiac Myocytes; Cardiovascular system; Cell Aging; Cell Death; Child; Chronic; Coculture Techniques; Collaborations; Communication; Conditioned Culture Media; Critical Thinking; Data; Disease Progression; Down-Regulation; Endothelial Cells; Environment; Failure; Fibroblasts; Foundations; Future; Gene Expression Profile; Gene Targeting; Genes; Heart failure; Histopathology; Hypertrophy; In Vitro; Laboratories; Left ventricular structure; Link; Mediating; Mediator of activation protein; Medical; Mentors; Mentorship; MicroRNAs; Mitochondria; Modeling; Molecular; Mus; Myocardial; Operative Surgical Procedures; Oxidants; Pathway interactions; Patients; Phenotype; Physicians; Plasma; Predisposition; Production; RNA-Induced Silencing Complex; Reactive Oxygen Species; Research; Right Ventricular Hypertrophy; Role; Scientist; Site; Stress; Testing; Training; Training Programs; Untranslated RNA; Vascular Endothelial Growth Factors; Work; angiogenesis; base; career; career development; cohort; congenital heart disorder; in vivo; interest; novel; overexpression; oxidant stress; paracrine; pressure; programs; public health relevance; research study; response; senescence; skills; small molecule; therapeutic target; transcriptome sequencing; vector

 DESCRIPTION (provided by applicant): This proposal describes a five-year career development program to prepare the candidate, Dr. Sushma Reddy, for a career as an independent scientist evaluating the mechanisms of right heart failure. This program will expand Dr. Reddy's scientific background in cardiovascular research by providing technical training and expertise in myocardial, mitochondrial and endothelial biology through focused course work, technical training and targeted externships. In addition, Dr. Reddy's successful transition from a mentored clinician scientist to an independent scientist will be accomplished by strengthening skills in critical thinking, communication, collaboration, mentorship and laboratory management. MicroRNAs (miRs) are small non-coding RNAs that have emerged as crucial regulators of cardiac remodeling. However, there is minimal data on their role in right ventricular hypertrophy (RVH) and failure (RVF). Understanding the mechanisms of RV remodeling is a critical question for many patients with congenital heart disease, given that the afterload stressed RV is more likely to fail compared to the left ventricle (LV), and that standard heart failure therapies fail o work in patients with RVF. Although the molecular responses of the RV and LV to pressure overload are largely similar, there are key differences in regulators of oxidant stress and angiogenesis which could explain the enhanced vulnerability of the RV. Dr. Reddy's objective is to elucidate the role of miRs as a mechanism for these RV-LV differences. Using a murine model, she has identified miRs 34a, 28, 93 and 148a as unique to RVH/RVF. Of interest, all four miRs are expressed only in non-cardiomyocytes yet may have their greatest effects in cardiomyocytes. She hypothesizes that RV-specific non-cardiomyocyte miR-34a, through crosstalk with cardiomyocytes, is responsible for the early failure of antioxidant defenses and the attenuated angiogenic response in RVF. Aim 1 will evaluate the mechanisms by which miR-34a regulates the transition from RVH to RVF. Overexpression of miR-34a in fibroblasts, endothelial cells and cardiomyocytes will evaluate effects on ROS production, antioxidant defenses, and mediators of cell death and angiogenesis, as well as the mechanism of miR-34a crosstalk with cardiomyocytes and the paracrine role of exosomes. Aim 2 will evaluate the in vivo functional significance of miR-34a using LNA antimiRs to rescue RVF in her murine model, identify novel target genes using transcriptome and RISCome sequencing, and identify plasma biomarkers of disease progression in children with RVH/RVF. Future studies will evaluate (i) the mechanism of action of miRs 28, 93 and 148a, either singly or in concert in the RV susceptibility to heart failure; (ii) the role of these miRs in a model of chronic pressure overload and (iii) validate plasma biomarkers in a larger cohort of children. In summary, these studies will aid in developing RV-specific heart failure therapies and identify biomarkers of RV failure, allowing earlier medical or surgical intervention.

 描述（由申请人提供）：该提案描述了一个为期五年的职业发展计划，旨在为候选人苏什玛·雷迪博士（Dr. Sushma Reddy）做好准备，成为评估右心衰竭机制的独立科学家。该项目将通过重点课程、技术培训和有针对性的实习，提供心肌、线粒体和内皮生物学方面的技术培训和专业知识，从而扩大雷迪博士在心血管研究方面的科学背景。此外，雷迪博士从一名受指导的临床科学家成功转变为一名独立科学家，将通过加强批判性思维、沟通、协作、指导和实验室管理方面的技能来实现。 MicroRNA (miR) 是一种小型非编码 RNA，已成为心脏重塑的关键调节因子。然而，关于它们在右心室肥厚 (RVH) 和衰竭 (RVF) 中的作用的数据很少。了解 RV 重塑机制对于许多先天性心脏病患者来说是一个关键问题，因为与左心室 (LV) 相比，后负荷应激的 RV 更容易衰竭，并且标准心力衰竭治疗对 RVF 患者无效。尽管右心室和左心室对压力超负荷的分子反应在很大程度上相似，但氧化应激和血管生成的调节因子存在关键差异，这可以解释右心室脆弱性增强的原因。 Reddy 博士的目标是阐明 miR 作为这些 RV-LV 差异机制的作用。利用小鼠模型，她确定了 RVH/RVF 特有的 miR 34a、28、93 和 148a。有趣的是，所有四种 miR 均仅在非心肌细胞中表达，但可能在心肌细胞中发挥最大作用。她推测 RV 特异性非心肌细胞 miR-34a 通过与心肌细胞的相互作用，导致了 RVF 中抗氧化防御的早期失败和血管生成反应的减弱。目标 1 将评估 miR-34a 调节 RVH 向 RVF 转变的机制。成纤维细胞、内皮细胞和心肌细胞中 miR-34a 的过表达将评估对 ROS 产生、抗氧化防御、细胞死亡和血管生成介质的影响，以及 miR-34a 与心肌细胞串扰的机制以及外泌体的旁分泌作用。目标 2 将使用 LNA antimiR 评估 miR-34a 在小鼠模型中拯救 RVF 的体内功能意义，使用转录组和 RISCome 测序鉴定新的靶基因，并鉴定 RVH/RVF 儿童疾病进展的血浆生物标志物。未来的研究将评估 (i) miR 28、93 和 148a 的作用机制，无论是单独还是协同作用，对 RV 对心力衰竭的易感性； (ii) 这些 miR 在慢性压力超负荷模型中的作用，以及 (iii) 在更大的儿童群体中验证血浆生物标志物。 总之，这些研究将有助于开发 RV 特异性心力衰竭疗法并确定 RV 衰竭的生物标志物，从而实现早期医疗或手术干预。