apoE, arterial biomechanics, and cardiovascular disease

apoE、动脉生物力学和心血管疾病

• 批准号: 9081644
• 负责人: Richard Assoian
• 金额: $ 43.27万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2018-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9081644
• 关键词: Accounting; Address; Adhesions; Adult; Affect; Apolipoprotein E; Arterial Fatty Streak; Arteries; Atherosclerosis; Attenuated; Biology; Biomechanics; Cardiovascular Diseases; Cells; Cholesterol; Collaborations; Collagen; Complement; Cre-LoxP; Data; Development; Disease; Elasticity; Extracellular Matrix; Extracellular Matrix Proteins; Fibrillar Collagen; Fibronectins; Gene Expression; Genes; Goals; Guanosine Triphosphate; Health; High Density Lipoproteins; In Vitro; Infiltration; Integrins; Knockout Mice; Lesion; Link; Lipid Binding; Lipoproteins; Mechanics; Microfabrication; Mus; Non-Fibrillar Collagens; Pathway interactions; Plasma; Production; Property; Protein-Lysine 6-Oxidase; Publications; Recording of previous events; Reporting; Rho-associated kinase; Risk Factors; Role; Signal Transduction; Smooth Muscle Myocytes; System; Technology; Testing; Tissue Model; Tissues; Work; adhesion receptor; arterial stiffness; cell motility; feeding; genome-wide; in vivo; inhibitor/antagonist; interest; macrophage; monocyte; mouse model; novel; research study; response; rho

DESCRIPTION (provided by applicant): Arterial stiffening is a risk factor for cardiovascular disease, but how arteries stay supple and how arterial stiffness contributes to disease are unknown. Our preliminary studies show that arterial elasticity is maintained by Apo lipoprotein E (apoE) and apoE-containing HDL through a suppressive effect on the expression of extracellular matrix genes. ApoE interrupts a mechanically driven feed-forward loop that increases the expression of collagen-I, fibronectin, and lysyl oxidase in response to substratum stiffening. These effects are independent of the apoE lipid-binding domain. Arterial stiffness is increased in apoE-null mice, this stiffening can be reduced by administration of the lysyl oxidase inhibitor, BAPN, and BAPN treatment attenuates atherosclerosis despite highly elevated cholesterol. Macrophage abundance in lesions is reduced by BAPN in vivo, and monocyte/macrophage adhesion is reduced by substratum softening in vitro. Mechanistically, we show that apoE and apoE-containing HDL inhibit Rho-GTP activity and reduce intracellular force in VSMCs. These changes in VSMC mechanics then affect ECM gene expression. Finally, we show that in addition to regulating (fibrillar) collagen-I, apoE and apoE-HDL inhibit the expression of collagen-VIII, a non-fibrillar collagen that has profound effects on VSMC function and atherosclerosis, yet is largely unexplored in terms of its mechanical properties and mechanistic effects. Overall, our data describe a completely new role for apoE and apoE-HDL that is independent of plasma cholesterol levels, intimately connected to cell and tissue mechanobiology, and causally linked to protection from atherosclerosis. We now propose three specific aims to characterize the relationships between apoE, intracellular force, matrix remodeling, and protection from atherosclerosis. In Aim 1, we will use a new micro fabrication platform of VSMC micro-tissues to study the effect of collagen-VIII on Rho-activity, contractility, ECM gene expression, and tissues stiffness in 3D. We will also use this system to determine how collagen-VIII controls the mechanical response to apoE. These in vitro studies will be complemented with an ex vivo analysis of arterial stiffness in apoE+/+ and apoE-/- arteries isolated from WT and collagen-VIII deficient mice. In Aim 2, we examine the mechanism by which stiffness controls atherosclerotic lesion development, with the particular goal of identifyin mechano-sensitive adhesion receptors that account for stiffness-dependent attachment of monocytes and macrophages to sub endothelial ECM protein. As in Aim 1, complementary in vivo experiments with existing mouse models will test the effect of arterial stiffness on monocyte abundance in vivo. Aim 3 will link the results in the first two aims by developing a new mouse model that can delete RhoA from VSMCs and establish the effect of reduced intracellular force on ECM gene expression, arterial stiffness, and atherosclerosis in vivo. This work brings together a team of three PI's (Assoian, Chen and Bendeck) with complementary expertise and an established track record of co- publication who, jointly, will establish how this novel regulatin of the ECM and VSMC mechanics by apoE provides cholesterol-independent protection against cardiovascular disease.

描述（由申请人提供）：动脉僵硬是心血管疾病的危险因素，但是动脉如何保持柔软以及动脉僵硬如何对疾病有效。我们的初步研究表明，通过对细胞外基质基因表达的抑制作用，Apo脂蛋白E（APOE）和含APOE的HDL维持动脉弹性。 APOE中断机械驱动的前馈环，该环响应于底层僵硬而增加了胶原蛋白I，纤连蛋白和赖氨酸氧化酶的表达。这些作用与ApoE脂质结合域无关。 Apoe-Null小鼠的动脉僵硬量增加，通过赖氨酸氧化酶抑制剂，BAPN和BAPN治疗可以降低这种僵硬，尽管胆固醇升高，但仍会减少动脉粥样硬化。 BAPN在体内减少了病变中的巨噬细胞丰度，并且通过体外底层软化减少了单核细胞/巨噬细胞粘附。从机械上讲，我们表明含APOE和含APOE的HDL会抑制Rho-GTP活性并减少VSMC中的细胞内力。然后，VSMC力学的这些变化会影响ECM基因表达。最后，我们表明，除了调节（原纤维）胶原蛋白，APOE和APOE-HDL外，还抑制了胶原蛋白VIII的表达，胶原蛋白VIII是一种非纤维胶原蛋白，对VSMC功能和动脉粥样硬化具有深远的影响，但在很大程度上对其机械性能和机械作用而言是无法解释的。总体而言，我们的数据描述了与血浆胆固醇水平无关的APOE和APOE-HDL的全新作用，该角色与细胞和组织机械生物学密切相关，并且与动脉粥样硬化的保护息息相关。现在，我们提出了三个特定的目的，以表征APOE，细胞内力，基质重塑和免受动脉粥样硬化的保护之间的关系。在AIM 1中，我们将使用一个新的微型制造平台VSMC微型组织来研究胶原蛋白VIII对Rho活性，收缩性的影响， ECM基因表达和3D的组织刚度。我们还将使用该系统来确定胶原蛋白VIII如何控制对APOE的机械响应。这些体外研究将与从WT和胶原蛋白-VIII缺乏小鼠分离的APOE+/+和APOE - / - 动脉中的动脉刚度的离体分析相辅相成。在AIM 2中，我们研究了刚度控制动脉粥样硬化病变的发育的机制，其特定目标是识别固定机械敏感的粘附受体，这些粘附受体解释了单核细胞和巨噬细胞对子内皮ECM蛋白的僵硬依赖性附着。与AIM 1一样，与现有小鼠模型进行的互补体内实验将测试动脉刚度对体内单核细胞丰度的影响。 AIM 3将通过开发一种可以从VSMC中删除RhoA的新小鼠模型中的前两个目标中的结果，并确定减少细胞内力对ECM基因表达，动脉僵硬和体内动脉粥样硬化的影响。这项工作汇集了一个由三个PI（Assoian，Chen和Bendeck）组成的团队，并具有互补的专业知识以及合作的既定记录记录，他们将共同确定APOE的ECM和VSMC机制的这种新颖的调节蛋白如何提供胆固醇独立的保护抗心血管疾病的保护。