Molecular mechanisms in Abdominal Aortic Aneuysm

腹主动脉瘤的分子机制

• 批准号: 8399030
• 负责人: Bo Liu
• 金额: $ 41.27万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-12-15 至 2014-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8399030
• 关键词: Abdomen; Abdominal Aortic Aneurysm; Anabolism; Aneurysm; Angiotensin II; Animals; Aorta; Apoptosis; Apoptotic; Attenuated; Behavior; Biological; Cells; Cessation of life; Chronic; Complex; Data; Death Rate; Degenerative Disorder; Development; Disease; Elastases; Functional disorder; Future; Gene Expression; Genes; Growth; Hospitals; Human; In Vitro; Individual; Infiltration; Inflammation; Inflammatory; Investigation; Knockout Mice; Link; MEKs; Malignant neoplasm of prostate; Medial; Mediating; Mediator of activation protein; Mitogen-Activated Protein Kinases; Modeling; Molecular; Monocyte Chemoattractant Protein-1; Mus; Operative Surgical Procedures; Pathogenesis; Patients; Peptides; Perfusion; Phenotype; Phosphotransferases; Production; Proteins; Reagent; Regulation; Reporting; Resistance; Role; Rupture; Ruptured Aneurysm; Signal Transduction; Signaling Molecule; Smooth Muscle Myocytes; Stress; Testing; Therapeutic; Time; Tissues; United States; Up-Regulation; Vascular Diseases; age related; base; drug development; in vivo; inhibitor/antagonist; macrophage; malignant breast neoplasm; monocyte; mortality; mouse model; novel; novel therapeutics; prevent; programs; protein kinase C-delta; repaired; rho GTP-Binding Proteins; screening; tool; translational study; vascular inflammation

Abdominal aortic aneurysm is a common age related and potentially lethal disease that develops as the result of a complex interplay among chronic inflammation, extracelluar matrix (ECM) degradation, and impaired ECM biosynthesis associated with depletion of medial smooth muscle cells (SMCs). However, the precise role of medial SMCs in this intricate network has yet to be elucidated. Results from our preliminary studies suggest that the signaling molecule protein kinase C-delta (PKC¿) is upregulated in SMCs of human and animal aneurismal tissues. Using the CaCl2 model of aneurysm, we demonstrated that PKC¿ gene deficient mice are protected from the development of aneurysms. Preliminary histological analyses indicate that PKC¿ gene deficiency impairs infiltration of macrophages and prevents depletion of medial SMCs and degradation of ECM. These preliminary findings are novel and for the first time implicate PKC¿ in the pathogenesis of aneurysms. We speculate that PKC¿ might be an integral factor responsible for the apoptotic and pro-inflammatory behavior of SMCs associated with aneurysm. In this study, we propose three specific aims to test the hypothesis that PKC¿ is an important molecular factor contributing to medial SMC depletion and vascular inflammation. The pro-inflammatory function of PKCd is mediated through monocyte chemoattactant protein-1 (MCP-1). In Specific Aim I, we will confirm the aneurysm-resistant phenotype of PKC¿ knockout mice through the use of the CaCl2 model paired with a serial of histological analyses over the course of aneurysm development. In addition, we will test the role of PKC¿ using the elastase perfusion model that induces aneurysm through a different mechanism. In Specific Aim II, we will delineate mechanisms through which PKC¿ gene deficiency impairs aneurysm formation. First, we will test a new paradigm underlying MCP-1 gene expression involving Rho GTPase Cdc42 and MAP kinase ERK. Second, we will test whether restoring MCP-1 in the aortic wall rescues the impaired aneurysm in PKC¿ knockout mice. Third, we will assess the role of PKC¿ in macrophages and the potential contribution of inflammatory cells to the aneurysm resistant phenotype of PKC¿ null mice. In Specific Aim III, we will characterize two peptide inhibitors of PKC¿, one of which was developed during our preliminary studies, in order to develop a molecular reagent to antagonize PKC¿ in vivo. The potential efficacy of the selected inhibitor to attenuate aneurysm development will be determined using the CaCl2 model. We believe that arterial PKC¿ upregulation exemplifies an intracellular signaling network within SMCs that drives pro-inflammatory signaling and apoptosis. Through the proposed in vivo and in vitro studies, we will gain a better understanding of medial SMCs in the pathogenesis of abdominal aortic aneurysm, which will allow us to make contributions toward the development of novel therapies for this devastating vascular disease.

腹主动脉瘤是一种常见的与年龄相关的潜在致命性疾病， 慢性炎症、细胞外基质（ECM）降解和受损ECM之间的复杂相互作用 在一些实施方案中，平滑肌细胞是与中膜平滑肌细胞（SMC）耗竭相关的生物合成的一部分。然而， 在这个复杂的网络中的中间SMC还有待阐明。我们初步研究的结果表明 在人和动物的平滑肌细胞中，信号分子蛋白激酶C-δ（PKC？） 子宫内膜组织。使用CaCl 2动脉瘤模型，我们证明了PKC基因缺陷小鼠， 防止动脉瘤的发展。初步的组织学分析表明PKC基因 缺乏会损害巨噬细胞的浸润，并阻止中膜SMC的消耗和ECM的降解。 这些初步发现是新的，并首次暗示PKC在动脉瘤的发病机制。 我们推测，PKC可能是一个不可或缺的因素，负责细胞凋亡和促炎性 与动脉瘤相关的SMC的行为。在这项研究中，我们提出了三个具体目标，以测试 假设PKC是导致中膜SMC耗竭的重要分子因子， 血管炎症PKCd的促炎作用是通过单核细胞介导的 趋化蛋白-1（MCP-1）。在具体目标I中，我们将确认 通过使用CaCl 2模型结合一系列组织学分析， 动脉瘤的发展过程。此外，我们将使用弹性蛋白酶灌注模型测试PKC的作用。 通过不同的机制诱发动脉瘤在具体目标II中，我们将描述机制 PKC基因缺陷通过该途径损害动脉瘤的形成。首先，我们将测试一个新的范例 潜在的MCP-1基因表达涉及Rho GT3 Cdc 42和MAP激酶ERK。第二，我们将测试 恢复主动脉壁MCP-1是否能挽救PKC基因敲除小鼠受损的动脉瘤。三是 将评估PKC在巨噬细胞中的作用以及炎症细胞对巨噬细胞增殖的潜在贡献。 PKC敲除小鼠的动脉瘤抗性表型。在特定目标III中，我们将描述两种肽抑制剂 其中一种是在我们的初步研究中开发的，目的是开发一种分子试剂 在体内拮抗PKC。所选抑制剂减缓动脉瘤发展的潜在疗效 将使用CaCl 2模型确定。我们认为动脉PKC上调证实了 SMC内的细胞内信号网络，其驱动促炎信号传导和凋亡。 通过体内和体外研究，我们将更好地了解中膜平滑肌细胞， 腹主动脉瘤的发病机制，这将使我们能够对发展作出贡献 治疗这种毁灭性血管疾病的新疗法。