Signaling To and From the Vascular/Endothelial Compartment and Progression of HCM Linked to Sarcomere Mutations

项目摘要/摘要 肥厚型心肌病(HCM)是一种常见的遗传性心血管疾病 由于大多数突变发生在编码肌节/细胞骨架蛋白的基因中。尽管 经过几十年的基础和临床研究，我们对缺陷的认识存在严重差距 心肌细胞中的生物物理信号影响心脏其他细胞部分的功能 这种疾病的临床病程。我们已经报道，旨在使肌丝正常化的早期干预措施 这些特性只能部分阻止HCM的进展。此外，移除触发突变不会 总是倒行逆施。在这里提出的实验中，我们测试了关键的总体假设，但 血管/内皮细胞间隔的可治疗的、适应不良的改变发生在早期，并与 肥厚性心肌病进展过程中肌丝特性的变化与细丝突变有关 不同的生物物理和生化信号。初步数据有力地支持了发挥作用和需要 研究加重症状性肥厚性心肌病的血管重塑和内皮功能障碍。新奇数据 支持我们对河马/YAP/TAZ信号的关注，强调鞘氨酸-1-磷酸的保护作用 受体(S1PR)信号，这是内皮(EC)和心肌细胞(CM)共同的信号。我们的目标是 目的：1.测定冠脉功能下降、血管重塑和机械性能的变化。 TnT-R92Q和TM-E180G在向肥厚型心肌病转化的过程中具有不同的信号转导。 目的2.确定内皮细胞河马通路的恢复是否足以阻止HCM 进步。这里提供的证据表明EC HIPPO/YAP/TAZ信号在HCM进展需求中的作用 对其调控后果的调查，以及治疗干预是否改变了河马 发信号。目的3.评估导致河马通路失调的微环境信号 激活的YAP/TAZ保护性介质在HCM中的共翻译表达我们的方法包括 测定冠脉血流速度、血管/内皮组织学和 通过河马途径的关键组成部分的机械感觉，随着心功能和 肥厚性肌病进展过程中肌丝钙离子反应。我们将在HCM进展的早期治疗小鼠模型 使用S1PR激动剂和小分子抑制剂使肌丝对钙的敏感性和张力正常化 检测它们是否能恢复EC河马通路和血管生成信号。我们将确定EC和CM 特定疾病信号网络并确定HCM是否导致S1P输出和旁分泌受损 功能，通过丰富和探测与RiboTag报告基因杂交的小鼠的“功能共翻译体” HCM突变。实现我们的目标将提供有效和个性化的目标发现 肉芽肿病的治疗方法。

Project Summary/Abstract Hypertrophic cardiomyopathy (HCM) is a common familial cardiovascular disorder viewed as a genetic disease of the sarcomere, since most mutations occur in genes that encode sarcomere/cytoskeletal proteins. Despite decades of basic and clinical research, there are critical gaps in our knowledge concerning how defective biophysical signals in the myocyte influence the function of other cellular compartments of the heart during the clinical course of this disorder. We have reported that early interventions aimed at normalizing myofilament properties only partially prevent HCM progression. Moreover, removal of the triggering mutation does not always reverse progression. In experiments proposed here, we test the overall hypothesis that critical, but treatable, maladaptive modifications in the vascular/endothelial compartment occur early and in parallel with changes in myofilament properties in the progression of HCM linked to thin filament mutations triggering different biophysical and biochemical signals. Preliminary data strongly support a role for and a need to investigate vascular remodeling and endothelial dysfunction that exacerbate symptomatic HCM. Novel data support our focus on HIPPO/YAP/TAZ signaling with emphasis on protective effects of sphingsine-1-phosphate receptor (S1PR) signaling, which is common to the endothelium (EC) and myocytes (CM). Our aims are as follows: Aim 1. Determine the decline in coronary function, changes in vascular remodeling and mechano- sensing in HCM linked to mutationsTnT-R92Q and Tm-E180G with different signaling in progression to HCM. Aim 2. Establish whether restoration of the endothelial HIPPO pathway is sufficient to impede HCM progression. Evidence provided here for a role of EC HIPPO/YAP/TAZ signaling in HCM progression demands an investigation of the consequences of its regulation, and whether therapeutic interventions modify HIPPO signaling. Aim 3. Evaluate the microenvironmental signals responsible for HIPPO pathway dysregulation and co-translation expression of activated YAP/TAZ protective mediators in HCM. Our approach includes determination of the time course of changes in coronary flow velocity, vascular/endothelial histology, and mechano-sensing through key components of the HIPPO pathway, with changes in cardiac function and the myofilaments Ca2+-response during HCM progression. We will treat mouse models early in HCM progression with S1PR agonists, and small molecule inhibitors to normalize myofilament Ca2+ sensitivity and tension to examine whether they restore EC HIPPO pathway and angiogenic signaling. We will identity EC and CM specific disease signaling networks and determine whether HCM leads to impaired S1P export and paracrine function, by enriching and probing the "functional co-translatome" in the RiboTag reporter mice crossed with HCM mutations. Accomplishing our aims will provide discovery of targets for effective and individualized therapies for HCM.