Vascular Smooth Muscle Protein Quality Control and Aortic Aneurysm Formation

血管平滑肌蛋白质量控制与主动脉瘤形成

基本信息

批准号：
10714562
负责人：
Xiaochun Long
金额：
$ 69.26万
依托单位：
AUGUSTA UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-07-01 至 2027-04-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10714562
关键词：
Abdominal Aortic Aneurysm Address Angiotensin II Aortic Aneurysm Biochemical Biological Assay Blood Vessels Cell Lineage Cell Nucleus Complication Cyclic AMP Cyclic AMP-Dependent Protein Kinases Cyclic GMP Cyclic Nucleotides Development Dilatation - action Disease Disease Progression Dissection Down-Regulation Drug Targeting Elastases Etiology Family member Functional disorder Gatekeeping Gene set enrichment analysis Genes Genetic Transcription Human Hydrolysis Impairment In Vitro Intervention Knock-out Knockout Mice Mediating Modeling Morbidity - disease rate Mouse Strains Mus Muscle Contraction Muscle Proteins Operative Surgical Procedures Pathogenesis Pathway Analysis Pathway interactions Performance Pharmacologic Substance Phenotype Play Prevention Proteasome Inhibitor Proteins Quality Control Regulation Reporter Role Rupture Signal Transduction Smooth Muscle Myocytes System Testing Time Tissues Transgenic Mice Transgenic Organisms Ubiquitin Vascular Diseases Vascular Smooth Muscle abdominal aorta cell type combat cost epigenome glycogen synthase kinase 3 beta human disease improved misfolded protein mortality mouse model multicatalytic endopeptidase complex multiple omics myocardin novel overexpression phosphoric diester hydrolase prevent programs protein degradation protein expression proteostasis proteotoxicity therapeutic target transcriptome transcriptome sequencing virtual

项目摘要

PROJECT SUMMARY Abdominal aortic aneurysm (AAA) is a devastating disease carrying high morbidity and mortality due to the high likelihood of fatal dissection and rupture. There are currently no proven pharmaceutical treatments to prevent AAA progression. VSMC degeneration contributes largely to AAA pathogenesis, but the mechanism remains elusive. The ubiquitin proteasome system (UPS) serves as an essential protein quality control mechanism by degrading misfolded proteins and surplus normal proteins. While proteotoxicity resulting from insufficient UPS function has been widely accepted as an important mechanism for multiple degenerative human conditions, the implication of UPS dysfunction in AAA is completely unknown. Our pathway analysis in human AAA tissues revealed an association of UPS function with AAA. In a mouse model of AAA, accumulation of ubiquitinated proteins, a hallmark of impaired UPS performance, precedes VSMC degeneration and AAA formation and is exacerbated with disease progression. This suggests that inadequate UPS performance may act as a novel mechanism underlying AAA etiology. MYOCD is a master switch of VSMC contractile gene program. How MYOCD is regulated and functions in AAA is unknown. Bulk RNA-seq in VSMCs showed an enrichment of UPS- related pathways in the top MYOCD-upregulated gene programs besides those relevant to VSMC contraction. Forced expression of MYOCD improved UPS performance while suppressing VSMC degeneration in cultured VSMCs and VSMC-specific MYOCD transgenic (Tg) mice at the early stage of AAA formation. MYOCD increased the expression of NFE2L1 and KLHL3, two key players of UPS function. These lines of evidence suggest a novel role of MYOCD in UPS function. Phosphodiesterases (PDEs), by catalyzing the hydrolysis of cAMP and cGMP to specifically modulate cyclic nucleotide signaling, play critical roles in VSMC pathophysiology and are proven drug targets for multiple human diseases. We found that PDE10A was the most induced PDE family member during AAA formation, while MYOCD protein expression was suppressed. Inhibition of PDE10A increased MYOCD protein, improved UPS performance, and suppressed AAA formation. These exciting preliminary findings support a novel hypothesis that downregulation of MYOCD protein by PDE10A impairs UPS performance, leading to VSMC degeneration and AAA. We propose three Aims to test this hypothesis. Aim 1 will use novel VSMC-specific Myocd knockout and Tg mice to determine the function of MYOCD in AngII-induced AAA model. Aim 2 will use a novel UPS reporter mouse line and biochemical assays to determine the importance of UPS function in MYOCD-regulated AAA and how MYOCD modulates UPS function. Aim 3 will determine how PDE10 promotes MYOCD protein degradation and PDE10A functions in UPS performance and AAA formation. This proposal will address for the first time the importance of UPS performance in VSMC degeneration and AAA formation, and elucidate a novel regulatory cascade comprising a druggable upstream modulator (PDE10A) and a downstream effector (MYOCD) in safeguarding UPS performance and proteostasis.

项目概要腹主动脉瘤（AAA）是一种毁灭性疾病，由于其高发病率和死亡率致命的解剖和破裂的可能性。目前尚无经过证实的药物治疗方法可以预防 AAA 进展。 VSMC 变性在 AAA 发病机制中起重要作用，但其机制仍然存在难以捉摸。泛素蛋白酶体系统 (UPS) 通过以下方式充当重要的蛋白质质量控制机制：降解错误折叠的蛋白质和多余的正常蛋白质。虽然 UPS 不足会导致蛋白质毒性功能已被广泛接受为多种人类退行性疾病的重要机制， UPS 功能障碍对 AAA 的影响尚不清楚。我们在人类 AAA 组织中的通路分析揭示了 UPS 功能与 AAA 的关联。在 AAA 小鼠模型中，泛素化的积累蛋白质是 UPS 性能受损的标志，先于 VSMC 退化和 AAA 形成，并且随着疾病进展而加剧。这表明 UPS 性能不足可能会成为一个新的问题 AAA病因学的潜在机制。 MYOCD是VSMC收缩基因程序的总开关。如何 MYOCD 受到调节，并且在 AAA 中的功能尚不清楚。 VSMC 中的 Bulk RNA-seq 显示 UPS- 的富集除了与 VSMC 收缩相关的通路外，顶级 MYOCD 上调基因程序中的相关通路。 MYOCD 的强制表达可提高 UPS 性能，同时抑制培养物中的 VSMC 变性 AAA 形成早期的 VSMC 和 VSMC 特异性 MYOCD 转基因 (Tg) 小鼠。心肌梗塞增加了 UPS 功能的两个关键角色 NFE2L1 和 KLHL3 的表达。这些证据线提出了 MYOCD 在 UPS 功能中的新作用。磷酸二酯酶 (PDE)，通过催化水解 cAMP 和 cGMP 特异性调节环核苷酸信号传导，在 VSMC 病理生理学中发挥关键作用并已被证明是多种人类疾病的药物靶点。我们发现 PDE10A 是诱导最多的 PDE AAA 形成期间的家族成员，而 MYOCD 蛋白表达受到抑制。 PDE10A 的抑制增加 MYOCD 蛋白，改善 UPS 性能，并抑制 AAA 形成。这些激动人心的初步结果支持一项新假设，即 PDE10A 下调 MYOCD 蛋白会损害 UPS 性能，导致 VSMC 退化和 AAA。我们提出三个目标来检验这一假设。目标1 将使用新型 VSMC 特异性 Myocd 敲除小鼠和 Tg 小鼠来确定 MYOCD 在 AngII 诱导中的功能 AAA 型号。目标 2 将使用新型 UPS 报告小鼠系和生化检测来确定重要性 MYOCD 调节 AAA 中的 UPS 功能以及 MYOCD 如何调节 UPS 功能。目标 3 将决定如何 PDE10 促进 MYOCD 蛋白降解，PDE10A 在 UPS 性能和 AAA 形成中发挥作用。该提案将首次阐述 UPS 性能在 VSMC 退化和 AAA 中的重要性形成，并阐明了一种新的调节级联，包括可药物上游调节剂（PDE10A）和保护 UPS 性能和蛋白质稳态的下游效应器 (MYOCD)。