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: 9100916
• 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/9100916
• 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; Health; 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 Genes; 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; 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 岁以上成年人死亡的一个重要原因。目前尚无成熟的药物治疗可用于预防 AAA 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 形成中发挥着关键作用。虽然 AT1 受体的几种下游信号和靶蛋白已被识别，但我们对主要负责 AAA 的近端信号传导事件的了解还存在巨大空白。不幸的是，AngII 阻滞剂对人类 AAA 的功效似乎有限。 AT1 刺激诱导的关键 AAA 促进信号很可能被许多其他 AAA 促进危险因素（例如醛固酮 (Aldo)）所破坏，这表明单独使用 AngII 阻滞剂不足以作为治疗方法。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) 中的小窝膜微区介导金属蛋白酶 ADAM17 依赖性 EGFR 反式激活，这与 AngII 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。在 VSMC ADAM17 缺陷小鼠中，与 AAA 形成相关的 EGFR 激活、ER 应激和氧化应激也减弱。此外，ADAM17相关信号元件的丢失或抑制（敲除小窝结构蛋白、小窝蛋白-1或用EGFR抑制剂治疗）可预防AngII依赖性AAA以及ER/氧化应激。 ADAM17 表达增强和 EGFR 激活也在人类 AAA 中得到证实。虽然 EGFR 反式激活对于 VSMC 中的 Aldo/盐皮质激素受体 (MR) 信号转导似乎至关重要，但 VSMC 小窝 ADAM17/EGFR 轴是否对于 Aldo 介导的 AAA 至关重要尚不清楚。在这里，我们制定了以下 2 个目标来回答我们的关键假设。目的1.探讨VSMC ADAM17和EGFR在AAA中的贡献和机制。假设：VSMC ADAM17 通过 ADAM17/EGFR 激活的新型前馈循环诱导 ER 应激和随后的 AAA 相关基因/蛋白质，对于 AAA 的发育和/或破裂至关重要。目的 2. 研究 VSMC Cav1 机制及其对 AAA 小鼠模型的影响。假设：VSMC Cav1 沉默通过防止 BMX 激活血管 ADAM17 来防止 ER 应激和随后的 AAA 形成和/或破裂。为了实现这 2 个目标，将使用 3 种不同的 AAA 模型来治疗缺乏 VSMC ADAM17、EGFR 或 Cav1 的小鼠。对于 AngII 或 Aldo 依赖性 AAA 模型，将分别给小鼠输注 AngII 加 BAPN（一种赖氨酰氧化酶抑制剂）或用 DOCA 盐加 BAPN 治疗。对于不依赖 RAAS 的 AAA 模型，小鼠腹主动脉将用 CaCl2 加 PBS 处理。此外，这种不依赖于 RAAS 的 AAA 模型和培养的 VSMC 将与编码嵌入 miRNA 的 siRNA 的腺病毒一起使用，该 siRNA 靶向 ADAM17、EGFR、Cav1 或 BMX。该提案的完成将探索由血管小窝分隔信号分子引发的新型前馈循环机制，作为减少 AAA 发展的潜在治疗靶点。