Heart Function Decline and Aging

心脏功能衰退与衰老

• 批准号: 10427227
• 负责人: Wolfgang H Dillmann
• 金额: --
• 依托单位: VA SAN DIEGO HEALTHCARE SYSTEM
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-01-01 至 2022-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10427227
• 关键词: 3' Untranslated Regions; 5' Untranslated Regions; ATP Hydrolysis; Age; Aging; Animals; Antibodies; Biological Assay; Calcium; Cardiac; Cardiac Muscle Contraction; Cardiac Myocytes; Cessation of life; ChIP-seq; Chromatin; Collaborations; Complex; Consumption; Contracts; DNA; DNA Probes; Data; Development; Dominant-Negative Mutation; Elderly; Equipment; Gene Expression; Gene Expression Profile; General Population; Genes; Genetic Transcription; Health; Healthcare; Heart; Heart Mitochondria; Heart failure; Impairment; Ischemia; Knowledge; Lead; Link; Mediating; Messenger RNA; Metabolic; Metabolism; MicroRNAs; Mitochondria; Mitochondrial Matrix; Modeling; Molecular; Motor; Mus; Mutate; Normal Range; Pathway interactions; Performance; Pharmacology; Polymerase; Population; Production; Proteins; Protons; Reperfusion Injury; Reperfusion Therapy; Research; Research Personnel; Respiratory physiology; Role; Sodium; Testing; Transgenes; Translation Initiation; Transposase; Untranslated Regions; Veterans; Workload; adeno-associated viral vector; base; blood pump; calcium uniporter; chromatin immunoprecipitation; chromatin remodeling; deep sequencing; experimental study; gain of function; genome-wide; heart function; improved; improved functioning; in vivo; knock-down; link protein; loss of function; member; muscular structure; myocardial infarct sizing; new therapeutic target; novel; novel strategies; novel therapeutic intervention; pressure; respiratory; response; restoration; transcriptome sequencing; transgene expression

Heart failure (HF) is a significant health problem in the elderly population, including in Veterans. The basis for the diminished function of the old heart (OH, 19-22 month) and increased propensity to develop HF is only incompletely explored and poorly treated. Preliminary results show that in OH cardiac function is diminished, cardiac myocytes (CM) contract poorly, and decreased Mitochondrial (Mito) respiratory function occurs. Our preliminary results also show novel findings that in CM from OH versus young heart (YH, 2-3 month) the Mitochondrial Calcium Uniporter (MCU) Complex (MCUC) has markedly decreased calcium (Ca2+) conductance resulting in decreased Mito matrix freeCa2+ concentration ([Ca2+]m) which leads to decreased Mito respiratory, cardiac metabolic, and contractile function. Specific MCUC member proteins show decreased levels in OH CM. The level of the Essential MCU Regulator (EMRE) is decreased by 70% in OH CM. In the absence of EMRE, MCUC Ca2+ conductance is lost. In addition MCU shows a more modest 30% decline in OH CM. The principle hypothesis is that the performance of the OH can be markedly improved by restoring EMRE and MCU levels in OH CM (OH+EMRE+MCU) using adeno-associated viral vector (AAV)-based expression of transgenes (tges) encoding EMRE and MCU or pharmacological inhibition of Mito Ca2+ export. To test this hypothesis we pursue three closely linked Aims. In Aim 1 we enhance MCUC Ca2+ conductance by restoring EMRE and MCU in OH towards the YH range and determine its influence on Mito and cytosolic Ca2+ handling, Mito respiratory, cardiac metabolic and contractile function, and animal survival. We also inhibit the Mito sodium- Ca2+ exchanger (mNCLX) and Mito Ca2+ export with a pharmacological compound, returning [Ca2+]m to the YH level and improving CM contraction. In Aim 2 we determine if maladaptive consequences occur in OH+EMRE+MCU, especially increased CM death and increased myocardial infarct size (MI) with ischemia/reperfusion (I/R). Preliminary results show a decrease in MI size in OH+EMRE+MCU versus (vs) OH. Influences of dominant negative (dn) dnEMRE and dnMCU expression on Mito Ca2+ handling and CM contraction in YH and OH are investigated. We compare rescue effects in OH+EMRE+MCU vs expression of a SERCa2 tge in OH (OH+SERCa2). Preliminary results show similar basal and maximal ex vivo cardiac function in OH+EMRE+MCU and OH+SERCa2. In Aim 3 we explore molecular mechanisms mediating the marked decrease in EMRE protein levels in OH CM. Preliminary results point to an interaction of miRNA 215, which is 3.4-fold increased in OH CM, with the 5' UTR of EMRE mRNA inhibiting translation initiation. We also explore if chromatin remodeling to a more open state occurs in OH+EMRE+MCU vs OH with increased DNA accessibility enabling increased gene transcription, including of the SERCa2 gene. Chromatin remodeling involves chromatin remodeling motors which require ATP hydrolysis. Studies in YH, OH, and OH+EMRE+MCU are conducted with collaborators at San Diego VA and UCSD who have the expertise and equipment to perform the following experiments. We use the Assay for Transposase-Accessible Chromatin with deep Sequencing (ATAC-Seq) and Chromatin Immunoprecipitation Sequencing (Chip-Seq) with a Polymerase II antibody to probe DNA accessibility for gene transcription. Chip-Seq pathway enrichment and RNA Sequencing (RNA-Seq) are used to determine changes in gene expression. To establish a link to increased ATP levels we use CM from OH+EMRE+MCU and OH with or without the protonophore FCCP which rapidly dissipates the proton gradient and inhibits ATP formation. Limited preliminary results, which need to be confirmed and extended, from ATAC-Seq and Chip-Seq indicate increased DNA accessibility in OH+EMRE+MCU vs OH CM. Chip-Seq pathway enrichment analysis and RNA-Seq data indicate a shift in the gene expression profile to mRNAs encoding proteins linked to cardiac muscle contraction and muscle structure development in OH+EMRE+MCU vs OH. The closely linked Aims will lead to new knowledge and may result in novel therapeutic approaches.

心力衰竭（HF）是老年人群（包括退伍军人）的一个严重健康问题。的基础 老年心脏功能减弱（OH，19-22 个月）和发生心力衰竭的倾向增加只是 未完全探索且治疗不当。初步结果表明，OH 中心脏功能减弱， 心肌细胞（CM）收缩不良，线粒体（Mito）呼吸功能下降。我们的 初步结果还显示了新的发现，即 OH 的 CM 与年轻心脏（YH，2-3 个月）相比， 线粒体钙单向转运蛋白 (MCU) 复合物 (MCUC) 显着降低钙 (Ca2+) 电导 导致 Mito 基质游离 Ca2+ 浓度 ([Ca2+]m) 降低，从而导致 Mito 呼吸减少， 心脏代谢和收缩功能。特定 MCUC 成员蛋白在 OH CM 中表现出水平降低。 OH CM 中基本 MCU 调节器 (EMRE) 的水平降低了 70%。在没有 EMRE 的情况下， MCUC Ca2+ 电导丢失。此外，MCU 显示 OH CM 下降幅度更小，为 30%。原理 假设通过恢复 EMRE 和 MCU 可以显着提高 OH 的性能 使用腺相关病毒载体 (AAV) 表达 OH CM (OH+EMRE+MCU) 中的水平 编码 EMRE 和 MCU 的转基因 (tges) 或 Mito Ca2+ 输出的药理学抑制。为了测试这个 假设我们追求三个紧密相连的目标。在目标 1 中，我们通过恢复来增强 MCUC Ca2+ 电导 OH 中的 EMRE 和 MCU 朝向 YH 范围，并确定其对 Mito 和胞质 Ca2+ 处理的影响， Mito 呼吸、心脏代谢和收缩功能以及动物生存。我们还抑制 Mito 钠- Ca2+ 交换器 (mNCLX) 和 Mito Ca2+ 与药理化合物一起输出，将 [Ca2+]m 返回至 YH 水平并改善 CM 收缩。在目标 2 中，我们确定适应不良后果是否发生在 OH+EMRE+MCU，尤其是增加 CM 死亡和增加心肌梗死面积 (MI) 缺血/再灌注（I/R）。初步结果显示，与 OH 相比，OH+EMRE+MCU 中的 MI 大小有所减小。 显性失活 (dn) dnEMRE 和 dnMCU 表达对 Mito Ca2+ 处理和 CM 收缩的影响 对 YH 和 OH 进行了研究。我们比较 OH+EMRE+MCU 与 SERCa2 tge 表达的救援效果 在 OH (OH+SERCa2) 中。初步结果显示，离体心脏功能相似的基础和最大心脏功能 OH+EMRE+MCU 和 OH+SERCa2。在目标 3 中，我们探索介导标记的分子机制 OH CM 中 EMRE 蛋白水平降低。初步结果表明 miRNA 215 存在相互作用，即 OH CM 增加 3.4 倍，EMRE mRNA 的 5' UTR 抑制翻译起始。我们还探讨是否 OH+EMRE+MCU 与 OH 相比，DNA 可及性增加，染色质重塑为更开放的状态 能够增加基因转录，包括 SERCa2 基因的转录。染色质重塑涉及染色质 重塑需要 ATP 水解的马达。 YH、OH 和 OH+EMRE+MCU 的研究是通过 弗吉尼亚州圣地亚哥和加州大学圣地亚哥分校的合作者，拥有执行以下任务的专业知识和设备 实验。我们使用深度测序转座酶可及染色质分析 (ATAC-Seq) 并 使用聚合酶 II 抗体进行染色质免疫沉淀测序 (Chip-Seq)，以探测 DNA 可及性 用于基因转录。 Chip-Seq 通路富集和 RNA 测序 (RNA-Seq) 用于确定 基因表达的变化。为了建立与增加的 ATP 水平的联系，我们使用来自 OH+EMRE+MCU 的 CM 和 OH，带或不带质子载体 FCCP，可快速消散质子梯度并抑制 ATP 形成。 ATAC-Seq 和 Chip-Seq 的初步结果有限，需要确认和扩展 表明与 OH CM 相比，OH+EMRE+MCU 中的 DNA 可及性有所增加。 Chip-Seq 通路富集分析 RNA-Seq 数据表明基因表达谱向编码与心脏相关的蛋白质的 mRNA 转变。 OH+EMRE+MCU 与 OH 中的肌肉收缩和肌肉结构发育。紧密相连的目标将 带来新的知识并可能产生新的治疗方法。

项目成果

Diabetic Cardiomyopathy.

糖尿病心肌病。

• 发表时间: 2019
• 影响因子: 20.1
• 作者: Dillmann; Wolfgang H
• 通讯作者: Wolfgang H

Mechanisms underlying diabetic cardiomyopathy: From pathophysiology to novel therapeutic targets.

糖尿病心肌病的机制：从病理生理学到新的治疗靶点。

• 发表时间: 2020-04-01
• 期刊: Conditioning medicine
• 作者: Shuo Cong;C. Ramach;ra;ra;K. M. M. Mai Ja;Jonathan Yap;W. Shim;Lai Wei;D. Hausenloy
• 通讯作者: D. Hausenloy