Cytoskeletal Control of Yap in Heart Regeneration

项目总结/摘要 Hippo信号通路（HSP）是一种激酶级联反应，抑制细胞核定位和转录。 转录辅因子雅普的活性。在先前的工作中，在小鼠和猪中缺失HSP组分Sav， 心肌细胞（CM）与建立缺血性心肌病和心力衰竭（HF），结果逆转 由于核雅普增加和雅普靶基因的激活，HF和心脏功能改善。这些 突破性的发现表明，揭示调节雅普活性的方法对于治疗缺血性心脏病是有价值的。 心肌病和HF，这是本研究计划的目标。重要的是，雅普主要受以下因素的调节： 翻译后修饰（PTM），其控制雅普核/胞质亚细胞定位 动力学HSP激酶通过磷酸化雅普中保守的丝氨酸残基来抑制雅普的核定位。 当HSP活性较低时，雅普进入细胞核并与Tead家族转录因子复合， 激活参与多个细胞周期阶段进展的基因。除了HSP介导的 磷酸化，最近发现赖氨酸乙酰化-脱乙酰化循环控制雅普核- 细胞质定位为开发心肌病的新疗法提供了机会， 在这项研究计划中。 蛋白质乙酰化-脱乙酰化对局部细胞环境的代谢状态非常敏感。 在心肌梗死（MI）期间，代谢迅速从线粒体氧化磷酸化转变为线粒体磷酸化。 糖酵解由于缺氧CM。因此，赖氨酸乙酰化，一个主要的PTM密切相关 与新陈代谢相关的基因也发生了改变HF改变心肌代谢有助于 疾病的发病机制和调节它可以服务于创新的治疗目的强调了 识别HF患者的代谢特征的重要性。因此，关键是要澄清雅普 对心肌梗死后环境因素或代谢变化的反应。拟议的研究是基于初步的 数据显示MI后，雅普/细胞骨架相互作用需要雅普乙酰化，其中雅普 结合非肌肉肌动蛋白丝。这些数据揭示了MI诱导的代谢转变途径，其中 乙酰化促进雅普与细胞质中稳定的微管网络隔离， 不利于心脏再生这些拟议研究的目的是研究磷酸化和 乙酰化雅普在HF和低HSP活性的背景下，使用先进的基因组学，基因疗法， 小鼠HF模型。这些研究将揭示MI后代谢变化如何通过赖氨酸调节雅普活性 CM中的乙酰化以及雅普如何调节CM细胞骨架。使用临床批准的化合物， 靶向代谢底物/中间体、赖氨酸乙酰转移酶和赖氨酸脱乙酰酶，这些 研究将指导靶向雅普乙酰化用于HF治疗的新策略的开发。

Project Summary / Abstract The Hippo-signaling pathway (HSP), a kinase cascade, inhibits nuclear localization and transcriptional activity of YAP, a transcription co-factor. In previous work, deletion of the HSP component Sav in mouse and pig cardiomyocytes (CMs) with established ischemic cardiomyopathy and heart failure (HF), results in reversal of HF and improved heart function due to increased nuclear YAP and activation of YAP target genes. These groundbreaking findings indicate that uncovering methods to modulate YAP activity is valuable to treat ischemic cardiomyopathy and HF, which is the goal of this research program. Importantly, YAP is primarily regulated by post-translational modifications (PTMs), which control YAP nuclear/cytoplasmic subcellular localization dynamics. HSP kinases inhibit YAP nuclear localization by phosphorylating conserved serine residues in YAP. When HSP activity is low, YAP enters the nucleus and complexes with Tead family transcription factors to activate genes involved in progression through multiple cell cycle phases. In addition to HSP-mediated phosphorylation, the recent discovery that a Lysine acetylation-deacetylation cycle controls YAP nuclear- cytoplasmic localization provides an opportunity to develop novel therapies for cardiomyopathy, which will be investigated in this research program. Protein acetylation-deacetylation is very sensitive to the metabolic state of the local cellular environment. During myocardial infarction (MI), metabolism quickly shifts from mitochondrial oxidative phosphorylation to glycolysis due to oxygen deficiency in CMs. Consequently, Lysine acetylation, one of the main PTMs closely associated with metabolism, is also altered. The notion that HF-altered myocardial metabolism contributes to disease pathogenesis and that regulating it may serve innovative therapeutic purposes underscores the importance of identifying the metabolic characteristics of HF patients. It is therefore critical to clarify how YAP responds to post-MI environmental factors or metabolic changes. The proposed studies are based on preliminary data revealing that following MI, YAP acetylation is required for YAP/cytoskeleton interactions, wherein YAP binds the non-muscle actin filaments. These data reveal an MI-induced metabolic shift pathway wherein acetylation promotes YAP sequestration with the stabilized microtubule network in the cytoplasm, which is detrimental to cardiac regeneration. The aims of these proposed studies are to investigate phosphorylated and acetylated YAP in the contexts of HF and low HSP activity using advanced genomics, gene therapies, and mouse HF models. These studies will reveal how metabolic shifts after MI regulate YAP activity via Lysine acetylation in CMs and how YAP regulates the CM cytoskeleton. Using clinically approved compounds that target metabolic substrates/intermediates, Lysine acetyltransferases, and Lysine deacetylases, these studies will guide the development of new strategies to target YAP acetylation for HF treatment.