PPARgamma, Endothelial Inflammation, and Atherosclerosis

PPARgamma、内皮炎症和动脉粥样硬化

• 批准号: 7429097
• 负责人: Jun-Ichi Abe
• 金额: $ 45.78万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-01 至 2010-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7429097
• 关键词: JUN kinase; RNA interference; atherosclerosis; confocal scanning microscopy; disease /disorder etiology; disease /disorder model; enzyme activity; gene expression; genetic transcription; genetically modified animals; hemodynamics; human tissue; inflammation; laboratory mouse; laboratory rabbit; mitogen activated protein kinase; molecular pathology; nuclear factor kappa beta; organ culture; pathologic process; peroxisome proliferator activated receptor; protein protein interaction; shear stress; tissue /cell culture; tumor necrosis factor alpha; vascular cell adhesion molecule; vascular endothelium

There is increasing support for the idea that inflammation plays a major role in the development of atherosclerosis. Peroxisome proliferator-activated receptors (PPARgamma) are ligand-activated transcription factors that form a subfamily of the nuclear gene family. PPARgamma activators inhibit adhesion molecules expression in activated endothelial cells and significantly reduce monocyte/macrophage homing to atherosclerotic plaques. We found that steady laminar flow activates ERK5, and increases PPARgamma transcriptional activation. In addition, to utilize the newly identified Hinge-helix 1 region of PPARgamma fragment (Hin-H1 fragment), which specifically disrupts ERK5/PPARgamma interaction and inhibits activated ERK5-mediated PPARgamma activation, will provide a great tool to explore the specific role of ERK5 and PPARgamma interaction in laminar flow-mediated anti-inflammatory effect. Based on our exciting preliminary data that ERK5 activation increases PPARgamma activity and that this may inhibit the expression of adhesion molecules, we hypothesize that laminar flow acts as an anti-inflammatory modulator by increasing PPARgamma transcriptional activity, and decreasing VCAM-1 expression in endothelial cell. To prove the contribution of PPARgamma transcriptional activity (which is regulated by ERK5) to the atheroprotective effect of flow in endothelial cells we propose three aims. Aim 1 : Using cultured endothelial cells, define the role of ERK5/PPARgamma on TNF-alpha induced NF-kappaB, VCAM-1 promoter activation and subsequent VCAM-1 expression. Aim 2: Using an ex vivo organ culture system of intact aorta, determine the role of PPARgamma and ERK5 in inflammation-related expression of adhesion molecules Aim 3: Using an atherosclerosis model, determine endothelial ERK5, JNK, NF-kappaB activation and VCAM-1 expression in vivo by using en face confocal microscopy, and detect the role of endothelial ERK5 in atherosclerosis formation using gain and loss of function mice. In aim 1 we will show the importance of ERK5/PPARgamma interaction to regulate laminar flow-mediated anti-inflammatory effect using Hin-H1 fragment and ERK5 siRNA in adenovirus vector. In aim 2 we will utilize the organ culture system, and determine the role of ERK5-PPARgamma in flow in intact vessels. In aim 3 we will use endothelial specific constitutively active(CA)-MEK5 or ERK5' knock out in LDLR-/- knock out(KO) mice, which has been characterized by atherosclerosis formation. We anticipate that CA-MEK5 will inhibit and ERK5 KO will promote atherosclerosis formation. These experiments will provide a new molecular mechanism for the anti-inflammatory effect of PPARgamma and flow associated with ERK5 activity.

越来越多的人支持炎症在动脉粥样硬化的发展中起主要作用的观点。 过氧化物酶体增殖物激活受体（PPARgamma）是配体激活的转录因子，其形成核基因家族的亚家族。PPARgamma激活剂抑制活化内皮细胞中粘附分子的表达，并显著减少单核细胞/巨噬细胞归巢至动脉粥样硬化斑块。我们发现，稳定的层流激活ERK 5，并增加PPARgamma转录激活。此外，利用新发现的特异性阻断ERK 5/PPARgamma相互作用并抑制活化的ERK 5介导的PPARgamma活化的PPARgamma片段Hinge-helix 1区域（Hin-H1片段），将为探索ERK 5和PPARgamma相互作用在层流介导的抗炎作用中的特异性作用提供一个很好的工具。基于我们激动人心的初步数据，即ERK 5激活增加了PPARgamma活性，这可能抑制粘附分子的表达，我们假设层流通过增加PPARgamma转录活性和降低内皮细胞中VCAM-1表达而起抗炎调节剂的作用。为了证明PPARgamma转录活性（由ERK 5调节）对内皮细胞中流动的动脉粥样硬化保护作用的贡献，我们提出了三个目标。目标1：使用培养的内皮细胞，确定ERK 5/PPARgamma在TNF-α诱导的NF-κ B、VCAM-1启动子激活和随后的VCAM-1表达中的作用。目标二：目的3：利用动脉粥样硬化模型，采用共聚焦显微镜检测在体内皮细胞ERK 5、JNK、NF-κ B活化和VCAM-1表达，并探讨其在炎症相关黏附分子表达中的作用。 内皮细胞ERK 5在动脉粥样硬化形成中的作用。在目标1中，我们将展示 ERK 5/PPARgamma相互作用对使用Hin-H1调节层流介导抗炎作用的重要性 片段和ERK 5 siRNA的重组腺病毒载体。在目标2中，我们将利用器官培养系统， ERK 5-PPARgamma在完整血管中的流动。在目的3中，我们将在LDLR-/-敲除（KO）小鼠中使用内皮特异性组成型活性（CA）-MEK 5或ERK 5 '敲除，其特征在于动脉粥样硬化形成。我们 预期CA-MEK 5将抑制动脉粥样硬化形成，而ERK 5 KO将促进动脉粥样硬化形成。这些实验将 为PPAR γ的抗炎作用和与ERK 5活性相关的流动提供了新的分子机制。