Vascular signal as a therapeutic target for abdominal aortic aneurysm

血管信号作为腹主动脉瘤的治疗靶点

• 批准号: 9310410
• 负责人: SATORU EGUCHI
• 金额: $ 39万
• 依托单位: TEMPLE UNIV OF THE COMMONWEALTH
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-01 至 2019-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9310410
• 关键词: 3' Untranslated Regions; Abdominal Aortic Aneurysm; Adenoviruses; Adult; Aldosterone; Angiotensin II; Animal Model; Aortic Aneurysm; Attenuated; BMX gene; Blood Vessels; Cardiovascular Diseases; Caveolae; Cell Culture Techniques; Cell model; Cells; DOCA; Data; Development; Disease; Elements; Epidermal Growth Factor Receptor; Event; Failure; GRP78 gene; Gene Proteins; Gene Silencing; Goals; Human; In Vitro; Intervention; Investigation; Knock-out; Knowledge; Link; Matrix Metalloproteinases; Mediating; Membrane Microdomains; Membrane Proteins; Metalloproteases; MicroRNAs; Mineralocorticoid Receptor; Modeling; Molecular; Molecular Chaperones; Mus; Muscle Cells; Oxidative Stress; Pathway interactions; Pharmacological Treatment; Phosphorylation; Prevention; Protein Tyrosine Kinase; Protein-Lysine 6-Oxidase; Proteins; Receptor Activation; Renin-Angiotensin-Aldosterone System; Reporting; Risk Factors; Role; Rupture; Ruptured Abdominal Aortic Aneurysm; Signal Transduction; Signal Transduction Pathway; Signaling Molecule; Small Interfering RNA; Sodium Chloride; Stress; Structural Protein; System; Testing; Transactivation; Vascular Smooth Muscle; Vascular remodeling; abdominal aorta; aged; caveolin 1; design; effective therapy; feeding; in vivo; inhibitor/antagonist; mortality; mouse model; novel; prevent; promoter; public health relevance; receptor; therapeutic target

 DESCRIPTION (provided by applicant): Abdominal aortic aneurysm (AAA) is a significant cause of mortality for adults aged >60 years. No established pharmacological treatment is currently available to prevent AAA advancement and/or rupture. Accumulating evidence suggests critical roles for the renin angiotensin aldosterone system (RAAS) in AAA formation. While several downstream signals and target proteins of AT1 receptor have been identified, there is a huge void in our knowledge regarding the proximal signaling events primarily responsible for AAA. Unfortunately, efficacies of the AngII blockers for human AAA appear to be limited. It is likely that the critical AAA promoting signal inducible upon AT1 stimulation is shard by many other AAA-promoting risk factors, such as by aldosterone (Aldo), indicating that an AngII blocker alone is insufficient as a treatment. Thus, we propose to determine alternative therapeutic targets for AAA in the AngII signal transduction pathway shared with other risk factors. We recently reported that caveolae membrane microdomains in vascular smooth muscle cells (VSMC) mediate a metalloprotease ADAM17-dependent EGFR transactivation, which is linked to vascular remodeling induced by AngII. Our preliminary data showed complete failure of AngII to induce AAA in mice lacking VSMC ADAM17 suggesting that ADAM17 is a potential target to prevent AAA. EGFR activation, ER stress and oxidative stress associated with AAA formation were also attenuated in VSMC ADAM17 deficient mice. Moreover, loss or inhibition of ADAM17 associated signaling elements (knockout of the caveolae structural protein, caveolin-1 or treatment with EGFR inhibitor) prevented AngII-dependent AAA as well as ER/oxidative stress. Enhanced ADAM17 expression and EGFR activation were also confirmed in human AAA. While EGFR transactivation appears critical for Aldo/mineralocorticoid receptor (MR) signal transduction in VSMC, whether the VSMC caveolae ADAM17/EGFR axis is critical for Aldo-mediated AAA is unclear. Here, we have developed the following 2 Aims to answer our key hypotheses. Aim 1. To investigate the contribution and mechanism of VSMC ADAM17 and EGFR in AAA. Hypothesis: VSMC ADAM17 is essential for AAA development and/or rupture through induction of ER stress and subsequent AAA associated genes/proteins via the novel feed forward loop of ADAM17/EGFR activation. Aim 2. To investigate the VSMC Cav1 mechanism and its consequence for the mouse models of AAA. Hypothesis: VSMC Cav1 silencing prevents ER stress and subsequent AAA formation and/or rupture through prevention of vascular ADAM17 activation by BMX. To accomplish these 2 Aims, 3 different AAA models will be used with mice lacking VSMC ADAM17, EGFR or Cav1. For an AngII- or Aldo-dependent AAA model, the mice will be infused with AngII plus BAPN, a lysyl oxidase inhibitor or treated with DOCA salt plus BAPN, respectively. For a RAAS-independent AAA model, the mouse abdominal aorta will be treated with CaCl2 plus PBS. In addition, this RAAS-independent AAA model and cultured VSMC will be used together with adenovirus encoding miRNA-embedded siRNA targeting ADAM17, EGFR, Cav1 or BMX. Accomplishment of this proposal will explore the novel feed-forward loop mechanism initiated by vascular caveolae compartmentalized signaling molecules as a potential therapeutic target for reducing AAA development.

 描述(由申请人提供)：腹主动脉瘤(AAA)是60岁以上成人死亡的重要原因。目前还没有成熟的药物治疗方法来防止AAA的进展和/或破裂。越来越多的证据表明，肾素-血管紧张素-醛固酮系统(RAAS)在AAA的形成中起着关键作用。虽然已经确定了AT1受体的几个下游信号和靶蛋白，但我们对主要导致AAA的近端信号事件的了解存在巨大的空白。不幸的是，血管紧张素受体阻滞剂对人类AAA的疗效似乎是有限的。在AT1刺激下可诱导的关键的AAA促进信号可能被许多其他促进AAA的危险因素所碎裂，例如由醛固酮(ALDO)，这表明单用血管紧张素转换酶抑制剂作为治疗是不够的。因此，我们建议在与其他危险因素共享的Angii信号转导通路中确定AAA的替代治疗靶点。我们最近报道，血管平滑肌细胞(VSMC)上的小凹膜微域介导一种依赖于金属蛋白酶ADAM17的EGFR反式激活，这种反式激活与血管紧张素转换酶II诱导的血管重塑有关。我们的初步数据显示，在缺乏VSMC ADAM17的小鼠中，AngII完全无法诱导AAA，这表明ADAM17是预防AAA的潜在靶点。与AAA形成相关的EGFR激活、内质网应激和氧化应激也在VSMC ADAM17缺陷小鼠中得到减弱。此外，ADAM17相关信号元件的缺失或抑制(敲除小窝结构蛋白、小窝蛋白-1或用EGFR抑制剂处理)可防止Angii依赖的AAA以及ER/氧化应激。ADAM17表达增强和EGFR活化在人AAA中也得到证实。虽然EGFR的反式激活在VSMC的Aldo/盐皮质激素受体(MR)信号转导中起关键作用，但VSMC小凹ADAM17/EGFR轴是否在Aldo介导的AAA中起关键作用尚不清楚。在这里，我们制定了以下两个目标来回答我们的关键假设。目的1.探讨VSMC、ADAM17和EGFR在AAA发病中的作用及机制。假设：VSMC ADAM17通过激活ADAM17/EGFR的新前馈环诱导内质网应激和随后的AAA相关基因/蛋白，对AAA的发展和/或破裂是必不可少的。目的2.探讨VSMC Cav1在AAA小鼠模型中的作用机制及其后果。假设：VSMC Cav1沉默通过阻止BMX激活血管ADAM17来防止内质网应激和随后的AAA形成和/或破裂。为了实现这两个目标，将使用3种不同的AAA模型来处理缺乏VSMC ADAM17、EGFR或Cav1的小鼠。对于Angii或Aldo依赖的AAA模型，小鼠将分别接受Angii+BAPN(赖氨酰氧化酶抑制剂)或DOCA盐+BAPN治疗。对于RAAS非依赖的AAA模型，将用CaCl2加PBS处理小鼠腹主动脉。此外，这种RAAS非依赖的AAA模型和培养的VSMC将与腺病毒一起使用，该病毒编码针对ADAM17、EGFR、Cav1或BMX的miRNA包埋的siRNA。这一提议的完成将探索由血管小窝区域化的信号分子启动的新的前馈环路机制，作为减少AAA发展的潜在治疗靶点。