VGLL4 and IRF2BP2 regulation of cardiomyocyte survival and hypertrophy

VGLL4和IRF2BP2对心肌细胞存活和肥大的调节

• 批准号: 9544377
• 负责人: Zhiqiang Lin
• 金额: $ 25.02万
• 依托单位: BOSTON CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2018-05-20
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9544377
• 关键词: Ablation; Adult; Apoptosis; Attenuated; Binding; Biomechanics; Cardiac; Cardiac Myocytes; Cardiac development; Cell Nucleus; Cell Proliferation; Cell Survival; Cells; Cessation of life; Characteristics; Chronic; Clinical; Data; Dependovirus; Development; Engineering; Family; Gene Expression; Genes; Genetic Transcription; Growth; Heart; Heart Diseases; Heart Hypertrophy; Heart Injuries; Heart Rate; Heart failure; Hospitalization; Hypertrophy; Lead; Mammals; Methods; Mitochondria; Mitotic; Modeling; Molecular; Mus; Myocardial; Myocardial Infarction; Myocardium; Necrosis; Nodal; Outcome; Pathway interactions; Patients; Pharmaceutical Preparations; Phenotype; Process; Reagent; Regulation; Regulatory Pathway; Role; Signal Transduction; Stress; System; Testing; Therapeutic; Tissues; Up-Regulation; cardiac repair; cardiogenesis; fetal; fly; gene therapy clinical study; heart function; improved; in vivo; insight; loss of function; member; mortality; mutant; postnatal; pre-clinical; prevent; programs; regenerative; therapeutic development; transcription factor

After myocardial infarction (MI), massive cardiomyocyte (CM) loss occurs due to apoptosis and necrosis. The surviving myocardium undergoes hypertrophic remodeling, which is beneficial in short term but detrimental in the long run. Dissecting the molecular mechanisms controlling cardiomyocyte hypertrophy and survival is critical to permit development of new heart failure therapeutic drugs. One signature of cardiac hypertrophy remodeling is the up regulation of a characteristic hypertrophic gene program, but it is not clear how these genes are activated, and which of these gene expression changes are beneficial or detrimental in heart injury or stress. The Hippo-YAP pathway is a key growth regulatory pathway conserved from flies to mammals. YAP, the terminal effector of this pathway, functions by binding to TEAD family transcription fac- tors. Data from our lab and other labs showed that the Hippo-Yap pathway is essential for car- diac development and cardiac repair. Vestigial like 4 (VGLL4), TEAD co-factor that suppresses YAP activity in mitotic tissues, is expressed preferentially in cardiomyocytes, where we have found that it is present both in the nucleus and in mitochondria. Our recent studies, now in press at Developmental Cell, show that VGLL4 antagonizes cardiac YAP-TEAD activity and is regu- lates postnatal cardiac maturation. Our preliminary data show that VGLL4 is essential for main- taining cardiac function. Another transcriptional regulator, IRF2BP2, is a major interaction partner of VGLL4 in cardiomyocytes. Our preliminary data show that IRF2BP2 is sufficient to suppress cardiomyocyte hypertrophic growth by attenuating NFAT signaling. Thus, VGLL4- IRF2BP2 form a previously unrecognized nodal point in cardiac hypertrophic signaling that likely also intersects with Hippo/YAP signaling. This proposal builds on these findings, aiming to dis- cover new molecular mechanisms regulating cardiomyocyte hypertrophy and survival. Integral to this study will be the development of therapeutically relevant adeno-associated virus (AAV) reagents for proof-of-concept pre-clinical gene therapy studies in mice. Specific Aims: Aim 1. To explore the roles of VGLL4 in the regulation of adult CM survival. We will study the mechanism of VGLL4 regulation CM survival, and engineer VGLL4 to tailor its activity for treating heart fail- ure. Aim 2. Study the mechanisms by which IRF2BP2 regulates cardiomyocyte hypertrophy. We will do both cardiac specific gain- and loss-of-function studies with IRF2BP2 in the normal heart, focusing on characterizing the cardiac phenotype. We will also test whether IRF2BP2 ac- tivation in the MI model decreases cardiac hypertrophic remodeling and CM death. Aim 3. Identify components of the hypertrophic gene program regulated by both IRF2BP2 and VGLL4. We will test whether IRF2BP2 activates cardiac fetal gene expression by alleviating VGLL4 sup- pression of TEAD1. These studies will inform efforts to improve heart function and suppress detrimental cardiac remodeling. -1-

心肌梗死（MI）后，大量的心肌细胞（CM）损失发生由于细胞凋亡 和坏死。存活的心肌进行肥厚性重构，这是有益的 但从长远来看是有害的。剖析了控制 心肌细胞肥大和存活对于新的心力衰竭的发展至关重要 治疗药物心肌肥厚重塑的一个标志是心肌细胞凋亡的上调。 特征性肥大基因程序，但尚不清楚这些基因是如何被激活的， 这些基因表达变化中的哪一个在心脏损伤或应激中是有益的或有害的。 Hippo-YAP途径是从果蝇到哺乳动物保守的关键生长调节途径。 雅普是该途径的末端效应子，通过结合TEAD家族转录因子发挥作用。 tors.来自我们实验室和其他实验室的数据表明，Hippo-Yap通路对汽车至关重要， diac发展和心脏修复。残留样4（VGLL 4），TEAD辅因子，抑制 有丝分裂组织中的雅普活性，优先在心肌细胞中表达，我们发现， 发现它存在于细胞核和线粒体中。我们最近的研究，现在出版 在发育细胞中，显示VGLL 4拮抗心脏YAP-TEAD活性，并且调节 延迟出生后心脏成熟。我们的初步数据表明，VGLL 4是主要的- 维持心脏功能。另一个转录调节因子IRF 2BP 2是一个主要的相互作用， 心肌细胞中VGLL 4的伴侣。我们的初步数据显示，IRF 2BP 2足以 通过减弱NFAT信号传导抑制心肌细胞肥大生长。因此，VGLL 4- IRF 2BP 2在心脏肥大信号传导中形成一个以前未被认识的节点， 也与Hippo/雅普信号传导交叉。该提案建立在这些调查结果的基础上，旨在讨论- 涵盖调节心肌细胞肥大和存活的新分子机制。积分 这项研究将是开发治疗相关的腺相关病毒（AAV）， 用于小鼠临床前基因治疗研究的概念验证试剂。具体目标：目标1。到 探索VGLL 4在调节成年CM存活中的作用。我们将研究其机制 VGLL 4调节CM存活，并设计VGLL 4以定制其治疗心力衰竭的活性- 当然。目标2.研究IRF 2BP 2调节心肌细胞肥大的机制。 我们将在正常对照组中用IRF 2BP 2进行心脏特异性功能获得和功能丧失研究。 心脏，重点是表征心脏表型。我们还将测试IRF 2BP 2 ac- 心肌梗死模型中的激活降低了心脏肥大性重塑和CM死亡。目标3. 鉴定由IRF 2BP 2和VGLL 4调节的肥大基因程序的组分。 我们将测试IRF 2BP 2是否通过减轻VGLL 4的抑制作用来激活心脏胎儿基因的表达。 TEAD 1的表达。这些研究将为改善心脏功能和抑制 有害的心脏重塑。 -1-