Functional and mechanistic delineation of HuR-Wisp1 signaling on myofibroblast activity

HuR-Wisp1信号对肌成纤维细胞活性的功能和机制描述

• 批准号: 10736289
• 负责人: Onur Kanisicak
• 金额: $ 71.88万
• 依托单位: UNIVERSITY OF CINCINNATI
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-06-01 至 2023-09-01
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10736289
• 关键词: Affect; Antigens; Binding; Cardiac; Cardiac Myocytes; Cells; Consensus; Data; Extracellular Matrix; Fibroblasts; Foundations; Gene Expression; Genetic; Goals; Heart; Heart Diseases; Heart failure; Human; In Vitro; Individual; Knowledge; Mechanics; Mediating; Mediator; Modeling; Morphology; Myocardial; Myocardium; Myofibroblast; Outcome; Paracrine Communication; Pathologic; Pathway interactions; Phenotype; Play; Population; Proteomics; RNA-Binding Proteins; Role; Signal Pathway; Signal Transduction; Therapeutic; Transforming Growth Factor beta; Work; aorta constriction; cell type; connective tissue growth factor; coronary fibrosis; heart function; heart preservation; in vivo; mechanical properties; mouse model; periostin; pharmacologic; pressure; response; response to injury; single-cell RNA sequencing; small molecule inhibitor; transcriptomics; translational impact

PROJECT SUMMARY: Cardiac fibrosis is regulated by the activation and phenotypic switching of quiescent cardiac fibroblasts (CFs) to active myofibroblasts (MFs). These MFs have extracellular matrix (ECM) remodeling and contractile functions which play a central role in cardiac remodeling in response to injury. As such, a consensus effort in the field is to manipulate fibroblast activity for therapeutic gain. However, a more complete understanding of the signaling pathways that regulate MF activity in cardiac remodeling remains an unmet need. We have previously demonstrated that the RNA binding protein Human antigen R (HuR) directly mediates hypertrophic signaling in cardiac myocytes (CMs), and that CM-specific genetic deletion or pharmacological inhibition of HuR reduces pathological remodeling and preserves cardiac function following transverse aortic constriction (TAC)-induced pressure overload, in part through a reduction in pro-fibrotic gene expression.1,2 In this proposal, we now present new preliminary data showing that HuR (1) expression in cardiac fibroblasts strongly correlates with established markers (periostin, 𝛼SMA, CTGF, etc) of MFs, (2) is necessary for TGFߚ- dependent MF activation and ECM-remodeling in vitro, and (3) CF-specific deletion of HuR preserves cardiac function following TAC. Critically, we have identified Wisp1 (Ccn4) as a downstream HuR-dependent mediator of MF activation, and show that expression of Wisp1 is sufficient to induce MF activity downstream/independent of HuR. The primary goals of this proposal are to determine the functional benefit of targeting HuR deletion in cardiac fibroblasts during pathological cardiac remodeling and the mechanistic impact of HuR deletion in CFs across other cell types in the myocardium (Aim 1), as well as the mechanisms by which HuR mediates Wisp1 expression in MFs, the functional benefit of fibroblast-specific Wisp1 deletion on cardiac remodeling, and the translational impact of these pathways on cardiac remodeling in human heart failure (Aim 2). Our central hypothesis is that HuR-Wisp1 signaling in cardiac fibroblasts is necessary for myofibroblast activity and promotes pathological cardiac remodeling. The specific aims of this proposal are to: (1) Determine the functional role of HuR in CFs in vivo and define its pleiotropic role across cell types during pathological cardiac remodeling. (2) Identify the functional and mechanistic role of HuR-dependent control of Wisp1 expression on MF activity and pathological cardiac remodeling. The expected results of this proposal will provide a mechanistic understanding of how HuR-Wisp1 signaling in cardiac fibroblasts modulates the functional response during pathological cardiac remodeling. Additionally, we will integrate previous translational work using a HuR small molecule inhibitor to better define the transcriptomic and functional changes across cardiac cell types in response to global and CF-specific abrogation of HuR signaling. In all, we expect this work to fill knowledge gaps in the signaling pathways that mediate cardiac fibroblast activation and ECM remodeling in the failing heart and provide a translational foundation for the targeting of HuR-Wisp1 signaling and/or HuR-dependent gene expression for therapeutic gain.

项目总结： 心脏纤维化由静止的心脏成纤维细胞的激活和表型转换调节 (CFS)至活化的肌成纤维细胞(MFS)。这些MFS具有细胞外基质(ECM)重塑和收缩 在损伤反应中心脏重塑中起核心作用的功能。因此，在 该领域的目的是操纵成纤维细胞的活性以获得治疗收益。然而，如果要更全面地了解 在心脏重塑中调节MF活性的信号通路仍然是一个未得到满足的需求。 我们之前已经证明，RNA结合蛋白人类抗原R(HUR)直接介导 心肌细胞(CMS)中的肥大信号以及CM特有的基因缺失或药理学 抑制HUR可减少横断型主动脉病变重塑和保护心功能 收缩(TAC)导致的压力超负荷，部分是通过减少促纤维化基因的表达。 这一建议，我们现在提供新的初步数据显示，HUR(1)在心脏成纤维细胞中表达 与已建立的MFS标志物(Periostin、𝛼SMA、CTGF等)密切相关，(2)是转化生长因子ߚ所必需的。 依赖的MF激活和体外ECM重塑，以及(3)Cf特异性缺失Hur对心脏的保护作用 TAC之后的功能。关键的是，我们已经确定Wisp1(Ccn4)是下游的HUR依赖的介体 并且表明Wisp1的表达足以在下游/非依赖性地诱导MF活性 关于Hur的。 这项建议的主要目标是确定靶向Hur缺失在心脏中的功能益处 CFS心脏病理性重构过程中的成纤维细胞及Hur缺失的机制影响 心肌中的其他细胞类型(目标1)，以及HUR介导Wisp1表达的机制 在MFS中，成纤维细胞特异性Wisp1缺失对心脏重构的功能益处，以及翻译 这些通路对人类心力衰竭心脏重构的影响(目标2)。我们的中心假设是 心脏成纤维细胞中的HUR-Wisp1信号是肌成纤维细胞活性所必需的，并促进 病理性心脏重塑。这项建议的具体目的是： (1)确定Hur在体内CFS中的功能作用，并确定其跨细胞类型的多效性作用。 病理性心脏重塑。 (2)确定依赖于HUR调控Wisp1表达对MF活性的功能和机制作用 和病理性心脏重塑。 这一提议的预期结果将提供对HUR-WISP1信号如何的机械性理解 心脏成纤维细胞在病理性心脏重塑过程中调节功能反应。此外，我们 将使用HUR小分子抑制剂整合之前的翻译工作，以更好地定义转录 不同类型心肌细胞对HUR的整体和Cf特异性消除的反应和功能变化 发信号。总之，我们希望这项工作能够填补介导心脏疾病的信号通路的知识空白。 成纤维细胞活化和ECM重塑在衰竭心脏中的作用 靶向Hur-Wisp1信号和/或Hur依赖的基因表达以获得治疗收益。