PPARG-dependent Mechanisms Control Endothelial-Smooth Muscle Coordination, Arterial Pressure, Vasomotor Function and Arterial Stiffness

PPARG 依赖性机制控制内皮-平滑肌协调、动脉压、血管舒缩功能和动脉僵硬度

• 批准号: 10092211
• 负责人: Curt Daniel Sigmund
• 金额: $ 92.4万
• 依托单位: MEDICAL COLLEGE OF WISCONSIN
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-02-06 至 2026-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10092211
• 关键词: Address; Antioxidants; Binding; Biological Availability; Blood Pressure; Blood Vessels; Complex; Contracts; Cyclic GMP; Data; Disease; Disease model; Endothelium; Future; Genetic Transcription; Hypertension; Investigation; Mediating; Mediator of activation protein; Modeling; Molecular; Molecular Target; Nitric Oxide; Nitric Oxide Pathway; Nuclear Receptors; Oxidation-Reduction; PPAR gamma; PPARG gene; Pathway interactions; Phenotype; Physiological; Play; Post-Translational Regulation; Production; Proteomics; RXR; Regulation; Research; Retinol Binding Proteins; Rho-associated kinase; Role; Signal Transduction; Smooth Muscle; Structure; Therapeutic; Vascular Diseases; Vascular Smooth Muscle; Vasoconstrictor Agents; Vasodilation; Vasodilator Agents; Vasomotor; Vision; arterial stiffness; blood pressure regulation; cell type; chromatin immunoprecipitation; comorbidity; constriction; cullin-3; genome-wide; novel; phosphodiesterase V; pressure; programs; protein degradation; response; sensor; transcription factor; transcriptome; ubiquitin-protein ligase

Summary/Abstract Blood vessels play an important role in the regulation of arterial blood pressure (BP). Precise BP regulation requires coordination between vasodilator and vasoconstrictor signals in the endothelium (EC) and smooth muscle (SMC). EC-derived nitric oxide (NO) is among the key signals which instruct the SMC to dilate or contract. Our studies show that the NO pathway is coordinately regulated through transcriptional and post- translational pathways initiated by PPARγ, a nuclear receptor transcription factor. Our data support the concepts that PPARγ: 1) acts as a sensor in EC to regulate redox state, and through this, bioavailability of NO, and 2) regulates the responsiveness of SMC to NO by independently controlling a) a RhoA/Rho kinase (ROCK) activity that promotes constriction, and b) production and stability of cyclic GMP (cGMP), a critical mediator of vasodilation. The range of PPARγ-dependent molecular mechanisms in both cell types is surprisingly complex; requiring novel transcriptional co-factors (e.g. retinol binding protein 7; RBP7) which form a transcriptional regulatory hub with PPARγ, and post-translational regulation of critical SMC mediators (RhoA and phosphodiesterase 5, PDE5) by Cullin-3 E3 ubiquitin ligase-mediated protein turnover. Importantly, this PPARγ initiated “final common pathway” has profound effects on vasomotor function, BP and vascular stiffness, and the studies proposed herein have potential implications for the treatment of these disorders. However, the signals which initiate and mediate these responses and the range of molecular targets remain poorly understood. This proposal will focus on two distinct PPARγ-regulated pathways. We will examine the PPARγ-RhoBTB1-Cullin-3 pathway in smooth muscle and will 1) determine if the RhoBTB1-Cullin-3 pathway can be exploited as a potential future therapeutic by assessing if RhoBTB1 can protect and reverse phenotypes in models of hypertension or in other disease models in which vascular dysfunction is a comorbidity, 2) determine if RhoBTB1 is important in other cells types including endothelium, and 3) employ a proteomic strategy to identify novel RhoBTB1 binding partners and Cullin-3 substrates in vascular smooth muscle. We will also examine the PPARγ-RBP7-anti-oxidant pathway in endothelium and will perform 1) structure function analysis to identify key mechanisms regulating PPARγ transcriptional activity by RBP7, and 2) genome wide transcriptome and chromatin immunoprecipitation studies to assess the contribution of RBP7 to mediated transcriptional activity of PPARγ and its obligate heterodimer RXR. This program will lead to new concepts and directions of investigation for the field and will not only deepen our understanding of the role of two fundamentally important pathways in the vasculature, but will also address fundamental transcriptional and post-translational mechanisms that are of relevance in many cell types.

摘要/摘要 血管在调节动脉血压（BP）中起着重要作用。精确的BP调节 需要在内皮（EC）中的血管扩张器和血管收缩信号之间的协调 肌肉（SMC）。 EC衍生的一氧化氮（NO）是指示SMC扩张或 合同。我们的研究表明，NO途径通过转录和后的转录和 PPARγ引发的翻译途径是核接收器转录因子。我们的数据支持 PPARγ的概念：1）在EC中充当调节氧化还原状态的传感器，通过此，NO的生物利用度， 2）通过独立控制A）RhoA/Rho激酶来调节SMC对NO的响应能力 （岩石）促进收缩的活动，b）环状GMP（CGMP）的产生和稳定性，这是一个关键 血管舒张的介体。两种细胞类型中PPARγ依赖性分子机制的范围是 令人惊讶的复杂；需要新型的转录副因素（例如视黄醇结合蛋白7; rbp7） 带有PPARγ的转录调节枢纽和关键SMC介质的翻译后调节（RhoA 和磷酸二酯酶5，PDE5），由Cullin-3 E3泛素连接酶介导的蛋白质更新。重要的是，这个 PPARγ引发的“最终公共途径”对血管舒缩功能，BP和血管具有深远的影响 僵硬，本文提出的研究对这些疾病的治疗具有潜在的影响。 但是，启动和介导这些响应的信号，分子靶标的范围仍然存在 理解不佳。该建议将集中于两种不同的PPARγ调节途径。我们将检查 PPARγ-RHOBTB1-CULLIN-3平滑肌中的途径，并将确定Rhobtb1-Cullin-3途径是否 可以通过评估Rhobtb1是否可以保护和逆转来探索作为未来疗法 高血压模型或其他血管功能障碍的表型是一种 合并症，2）确定Rhobtb1在包括内皮在内的其他细胞类型中是否重要，3）员工A 蛋白质组学策略以识别新型RhoBTB1结合伙伴和血管平滑中的Cullin-3底物 肌肉。我们还将检查内皮中的PPARγ-RBP7-抗氧化途径，并将执行1） 结构函数分析以识别RBP7调节PPARγ转录活性的关键机制， 2）基因组广泛的转录组和染色质免疫沉淀研究，以评估RBP7的贡献 介导PPARγ及其强制性异二聚体RXR的转录活性。该程序将导致新的 该领域的概念和投资方向，不仅会加深我们对 脉管系统中的两种根本重要的途径，但也将解决基本的转录和 在许多细胞类型中相关的翻译后机制。