Cytoskeletal Control of Yap in Heart Regeneration

项目概要/摘要 Hippo 信号通路 (HSP) 是一种激酶级联，抑制核定位和转录 YAP（一种转录辅助因子）的活性。在之前的工作中，小鼠和猪中 HSP 成分 Sav 的缺失 患有缺血性心肌病和心力衰竭（HF）的心肌细胞（CM），导致逆转 由于核 YAP 增加和 YAP 靶基因激活，导致心力衰竭和心脏功能改善。这些 突破性的发现表明，发现调节 YAP 活性的方法对于治疗缺血性脑病很有价值 心肌病和心力衰竭，这是该研究计划的目标。重要的是，YAP 主要受监管 翻译后修饰 (PTM)，控制 YAP 核/细胞质亚细胞定位 动态。 HSP 激酶通过磷酸化 YAP 中的保守丝氨酸残基来抑制 YAP 核定位。 当HSP活性较低时，YAP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 最近发现赖氨酸乙酰化-脱乙酰化循环控制 YAP 核- 细胞质定位为开发心肌病新疗法提供了机会，这将是 在本研究计划中进行了调查。 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。 在心肌梗塞 (MI) 期间，新陈代谢迅速从线粒体氧化磷酸化转变为 CM 中缺氧导致的糖酵解。因此，赖氨酸乙酰化是主要的 PTM 之一，与 与新陈代谢有关，也会发生改变。 HF 改变心肌代谢有助于 疾病的发病机制以及调节它可以服务于创新的治疗目的强调了 确定心力衰竭患者代谢特征的重要性。因此，澄清 YAP 如何 对心肌梗死后环境因素或代谢变化做出反应。拟议的研究基于初步 数据表明，MI 后，YAP 乙酰化是 YAP/细胞骨架相互作用所必需的，其中 YAP 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 YAP 与细胞质中稳定的微管网络的隔离，这是 不利于心脏再生。这些拟议研究的目的是研究磷酸化和 使用先进的基因组学、基因疗法和技术在 HF 和低 HSP 活性的情况下乙酰化 YAP 鼠标 HF 型号。这些研究将揭示 MI 后代谢变化如何通过赖氨酸调节 YAP 活性 CM 中的乙酰化以及 YAP 如何调节 CM 细胞骨架。使用临床批准的化合物 目标代谢底物/中间体、赖氨酸乙酰转移酶和赖氨酸脱乙酰酶，这些 研究将指导开发针对心力衰竭治疗的 YAP 乙酰化新策略。

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.