Elucidation of botulinum neurotoxin A mediated cerebral revascularization graft spasmolysis mechanisms

项目摘要 本研究的主要目的是研究A型肉毒毒素（BTX A）肾上腺素能和Rho 激酶通路首次阐明其在人脑中的痉挛作用机制 血管重建移植物。血运重建移植物狭窄和闭塞仍然是一个可怕的并发症， 可导致显著的发病率和死亡率。血管痉挛引起的移植物狭窄和闭塞被认为是 至少部分地通过肾上腺素能血管痉挛途径中增加的活性来介导。此外，证据 支持RhoA/Rho激酶（ROCK）途径在血管痉挛中的作用。尽管面临各种 建议的痉挛，没有单一的有效剂。包括解剖和生理变异性在内的因素 在血管重建管道中，患者人口统计学和合并症与移植物相关， 血管痉挛的发病机制和对痉挛药的反应。鉴于这些知识，理想的痉挛剂可能 需要调节多个通路以发挥治疗作用。 BTX A是一种强大的神经毒素，在临床实践中广泛用于治疗各种痉挛性疾病。 虽然其经典的胆碱能神经传递阻断范式已被广泛接受，证据表明， 已经描述了其他可能的机制。涉及肾上腺素能调节的其他机制， ROCK和内皮血管通路已在动物研究中报道。最近，我们的团队出版了 第一个描述使用BTX A预防脑血管重建移植物痉挛的初步研究。 拟定研究将利用BTX A治疗前后采集的剩余动脉组织样本， 脑血管搭桥手术我们最近成立了一个机构审查委员会， 冷冻的血管组织库，用于储存血管组织样本，并可用于研究 目的BTX A对两种主要血管痉挛的作用的靶组织、蛋白和分子水平分析 将利用本机构附属的核心设施和研究实验室进行路径。 阐明BTX A痉挛的作用机制将有助于填补目前的知识空白， 人类和动物研究，并可为II期临床疗效研究提供基础。这些发现也 有可能扩大BTX A在心脏血管重建中血管痉挛并发症的应用， 重建手术我们的基础科学合作，血管组织库和高临床量， 我们的脑血管重建中心有一个独特的环境来进行这项研究。

Project Summary The primary goal of this study is to investigate the effects of botulinum toxin A (BTX A) adrenergic and Rho kinase pathways elucidating, for the first time, its spasmolytic mechanism of action in human cerebral revascularization grafts. Revascularization graft stenosis and occlusion remains a formidable complication which can lead to significant morbidity and mortality. Graft stenosis and occlusion from vasospasm is thought to be at least partially mediated through increased activity in adrenergic vasospastic pathways. Additionally, evidence supporting the role of the RhoA/Rho kinase (ROCK) pathway in vasospasm has been described. Despite various proposed spasmolytics, there is no single effective agent. Factors including anatomic and physiologic variability in revascularization conduits, patient demographics and comorbidities have been associated with graft vasospasm pathogenesis and response to spasmolytics. Given this knowledge, the ideal spasmolytic agent likely needs to modulate multiple pathways to exert therapeutic effect. BTX A is a powerful neurotoxin widely used in clinical practice for the treatment of a variety of spastic conditions. Although its classic paradigm of cholinergic neural transmission blockade has been widely accepted, evidence for other possible mechanisms has been described. Other mechanisms involving modulation of adrenergic, ROCK and endothelial vasomotor pathways has been reported in animal studies. Recently, our group published the first pilot study describing use of BTX A for cerebral revascularization graft spasm prevention. The proposed study will utilize leftover arterial tissue samples collected pre- and post-BTX A treatment during cerebrovascular bypass surgery. We have recently established an Institutional Review Board approved fresh- frozen vascular tissue bank where the vascular tissue samples are stored and can be retrieved for research purposes. Targeted tissue, protein and molecular level analyses of BTX A effects on two major vasospastic pathways will be performed utilizing core facilities and research laboratories affiliated with our institution. Elucidating the mechanism of action for BTX A spasmolysis will help to fill a current gap in knowledge between human and animal studies and could provide the basis for a phase 2 clinical efficacy study. These findings also have the potential to expand the use of BTX A for vasospastic complications in cardiac revascularization and reconstructive surgery. Our basic science collaborations, vascular tissue bank and high clinical volume make our Cerebral Revascularization center a unique environment to perform this research.