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: 8940888
• 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/8940888
• 关键词: 3' Untranslated Regions; Abdominal Aortic Aneurysm; Adenoviruses; Adult; Aldosterone; Angiotensin II; Animal Model; Animals; Aortic Aneurysm; Attenuated; BMX gene; Blood Vessels; Cardiovascular Diseases; Caveolae; Cell Culture Techniques; Cell model; Cells; Cultured Cells; DOCA; Data; Development; Disease; Elements; Epidermal Growth Factor Receptor; Event; Failure; Figs - dietary; 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; Oxidative Stress; Pathway interactions; Pharmacological Treatment; Phosphorylation; Prevention; Protein Tyrosine Kinase; Protein-Lysine 6-Oxidase; Proteins; Receptor Activation; Receptor Signaling; Renin-Angiotensin-Aldosterone System; Reporting; Risk Factors; Role; Rupture; Ruptured Abdominal Aortic Aneurysm; Signal Transduction; Signal Transduction Pathway; Signaling Molecule; Small Interfering RNA; Smooth Muscle Myocytes; Sodium Chloride; Stress; Structural Protein; System; Testing; Transactivation; 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。目前尚无确定的药物治疗可用于预防AAA推进和/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。虽然已经鉴定了AT 1受体的几种下游信号和靶蛋白，但我们对主要负责AAA的近端信号事件的了解存在巨大空白。不幸的是，AngII阻滞剂对人AAA的功效似乎有限。很可能在AT 1刺激时可诱导的关键AAA促进信号被许多其他AAA促进风险因素（如醛固酮（Aldo））所分割，表明单独使用AngII阻滞剂作为治疗是不够的。因此，我们建议确定与其他危险因素共享的AngII信号转导通路中AAA的替代治疗靶点。我们最近报道，在血管平滑肌细胞（VSMC）的小窝膜微域介导的金属蛋白酶ADAM 17依赖性EGFR的反式激活，这是与血管生成素II诱导的血管重塑。我们的初步数据显示AngII在缺乏VSMC ADAM 17的小鼠中诱导AAA完全失败，这表明ADAM 17是预防AAA的潜在靶点。与AAA形成相关的EGFR活化、ER应激和氧化应激在VSMC ADAM 17缺陷小鼠中也减弱。此外，ADAM 17相关信号传导元件的丢失或抑制（caveolae结构蛋白、caveolin-1的敲除或EGFR抑制剂治疗）可预防AngII依赖性AAA以及ER/氧化应激。在人AAA中也证实了ADAM 17表达和EGFR活化增强。虽然EGFR反式激活似乎对VSMC中的Aldo/盐皮质激素受体（MR）信号转导至关重要，但VSMC小窝ADAM 17/EGFR轴是否对Aldo介导的AAA至关重要尚不清楚。在这里，我们开发了以下2个目标来回答我们的关键假设。目标1.探讨血管平滑肌细胞（VSMC）中ADAM 17和EGFR在AAA中的作用及机制。假设：VSMC ADAM 17通过诱导ER应激和随后的AAA相关基因/蛋白（经由ADAM 17/EGFR激活的新前馈环）对AAA的发展和/或破裂至关重要。目标2.探讨VSMC Cav 1在小鼠AAA模型中的作用机制及其对AAA的影响。假设：VSMC Cav 1沉默通过阻止BMX激活血管ADAM 17来防止ER应激和随后的AAA形成和/或破裂。为了实现这2个目的，将使用3种不同的AAA模型，其中包括缺乏VSMC ADAM 17、EGFR或Cav 1的小鼠。对于AngII依赖性或Aldo依赖性AAA模型，小鼠将分别用AngII加BAPN（赖氨酰氧化酶抑制剂）输注或用DOCA盐加BAPN处理。对于RAAS非依赖性AAA模型，将用CaCl 2加PBS处理小鼠腹主动脉。此外，这种RAAS非依赖性AAA模型和培养的VSMC将与编码靶向ADAM 17、EGFR、Cav 1或BMX的嵌入miRNA的siRNA的腺病毒一起使用。该提案的完成将探索由血管小窝区室化信号分子启动的新型前馈环机制，作为减少AAA发展的潜在治疗靶点。