Device-Based Pathway Intervention: Mechanistic Study of Cellular Localization of Proteolytic Enzymes in Thoracic Aortic Aneurysm Disease

项目概要： 胸主动脉瘤（TAA）是美国发病率和死亡率的主要原因。 心血管外科医生的管理难题。这种疾病 这一过程削弱了血管壁，导致扩张，通常进展到破裂。目前没有 存在有效的药物治疗。该实验室的主要重点是确定新的目标， TAA的非手术治疗。我们已经在小鼠中开发了TAA模型，并建立了原代TAA模型。 主动脉细胞培养来研究病理学的潜在机制。这些模型不仅 概括临床TAA的结构特征，但也复制了生物化学的变化， 介质的方式与人类疾病中观察到的一致。因此，本研究旨在 验证调节关键分子通路抑制动脉瘤形成的假设。 研究中的三种分子是：膜型1型基质金属蛋白酶（MT 1-MT3）， MMP）、弗林蛋白酶和miR-133 a。MT 1-MMP在TAA组织中升高，并且是TAA发展所必需的。 动脉瘤MT 1-MMP降解血管壁，激活其他酶，并改变细胞内的 表型TAA在MT 1-MMP缺陷小鼠（杂合敲除）中不形成。弗林河 包括MT 1-MMP在内的多种酶的激活剂在TAA中升高。这种分子 与广泛的疾病有关，我们的数据一致表明在动脉瘤中的作用 进展小的非编码RNA，miR-133 a，抑制MT 1-MMP和弗林蛋白酶。miR-133 a是 在TAA组织中减少。当将miR-133 a给予小鼠时，TAA不会形成。 这三种分子的细胞位置在TAA中改变。内吞作用（内化）， 胞吐作用（分泌）和囊泡运输（细胞内运输）都修饰上述分子的结构。 接触基质，并可能在动脉瘤的发展中发挥专门作用。这项研究将利用一个 促进核酸载体在小鼠胸主动脉中的细胞类型特异性表达的装置。 这些载体将直接调节（增加/减少/定位）丰度和 这三种分子的功能性正在研究中。因此，我们的方法是一种组合 一个既能增强严格性又能最大化治疗效果的方法。这项调查将定义新的和 TAA治疗干预的临床适用模式。

PROJECT SUMMARY: Thoracic aortic aneurysm (TAA) represents a major cause of morbidity and mortality in the United States and continues to be a difficult management problem for cardiovascular surgeons. This disease process weakens the vessel wall and leads to dilation that often progresses to rupture. Currently no effective medical therapy exists. The primary focus of this laboratory is defining novel targets for non-surgical treatment of TAAs. We have developed a model of TAA in mice and established primary aortic cell cultures to study the underlying mechanisms of pathology. These models not only recapitulate the structural hallmarks of clinical TAA, but also replicate the changes in biochemical mediators in ways that are consistent with what is observed in human disease. As such, this study aims to verify the hypothesis that regulation of key molecular pathways inhibits aneurysm formation. The three molecules under investigation are: the membrane type-1 matrix metalloproteinase (MT1- MMP), Furin, and miR-133a. MT1-MMP is elevated in TAA tissue and required for development of aneurysm. MT1-MMP degrades the vascular wall, activates other enzymes, and alters cellular phenotype. TAAs do not form in mice deficient of MT1-MMP (heterozygous knockout). Furin, an activator of multiple enzymes including MT1-MMP, is elevated in TAA. This molecule has been implicated in a vast range of diseases and our data consistently suggest a role in aneurysm progression. The small non-coding RNA, miR-133a, represses both MT1-MMP and Furin. miR-133a is reduced in TAA tissue. When miR-133a is administered to mice, TAAs do not form. Cellular location of these three molecules is altered in TAA. Endocytosis (internalization), exocytosis (secretion), and vesicle trafficking (intracellular transport), all modify the above molecules' access to substrates and likely play an obligate role in aneurysm development. This study will utilize a device that facilitates cell-type specific expression of nucleic acid vectors in the thoracic aorta of mice. These vectors will directly regulate (increase/decrease/localize) the abundance and functionality of the three molecules under investigation. Our approach is therefore a combinatorial one that both enhances rigor and maximizes therapeutic effect. This investigation will define novel and clinically applicable modalities for therapeutic intervention in TAA.