Role of bradykinin receptor 2 in tPA stroke therapy

项目摘要 组织纤溶酶原激活剂（tPA）的广泛使用，是唯一一种FDA批准的急性卒中治疗方法， 但其治疗时间窗狭窄和相关的脑出血风险仍然有限。缓激肽（BK）是 众所周知，其作为内皮依赖性血管扩张剂和强效促炎激动剂的作用。一 大量实验研究表明，中风后BK受体通过介导 中风后早期的炎症反应，表明BK减轻脑损伤。在 初步研究发现：1）tPA治疗后，通过血浆激肽释放酶，BK形成增加 2）中风后BK受体2拮抗剂与tPA治疗的共同施用减少了 出血转化; 3）B2 R激动剂在氧和葡萄糖期间不诱导内皮细胞死亡 剥夺; 4）脾切除或巨噬细胞耗竭小鼠与tPA减少脑出血; 5）BK 中风后输注增加出血转化，这在巨噬细胞耗尽的小鼠中被阻断。 拟议研究的目的是确定BK影响和激活的机制 tPA治疗后，巨噬细胞，从而导致脑出血通过促炎过程中血管 损伤我们的最终目标是阐明tPA治疗改善肿瘤的机制基础。 时间窗，使tPA更安全，更广泛地用于中风患者。我们建议测试 以下具体目的：（i）确定条件内皮细胞和巨噬细胞特异性 B2 R缺失对tPA诱导的出血转化的影响;（ii）表征BK在活化的 tPA治疗后巨噬细胞的积累和募集;（iii）描绘分子机制 BK通过其调节巨噬细胞功能及其与脑内皮细胞的相互作用。我会用这个 我获得了职业发展指导奖（K 01），以实现一系列培训目标，这些目标建立在我之前的 在神经科学的技能，而且还扩大了我的专业知识的方式，这是必不可少的，我过渡到 独立调查员这个应用程序的培训部分将建立在我的专业知识在免疫 通过研究tPA治疗后脑出血中涉及的血管损伤，与培训一起 在分子免疫生物学方面，这将使我能够建立自己的中风前沿研究计划。 职业发展活动将由乔治金博士与马格迪塞利姆博士合作指导， Kazuhide Hawakaya和Stephan Kissler，因为他们的科学专长领域，以及技术和 我从我们的导师关系中得到的科学建议我的职业发展活动将 侧重于：1）对实验室管理和组织的指导和指导; 2）开发和 我的独立研究计划的发展; 3）机构责任和履行要求， 推广和扩大我的科学网络; 4）授予写作技能。

Project Summary The widespread use of tissue plasminogen activator (tPA), the only FDA-approved acute stroke treatment, remains limited by its narrow therapeutic time window and related risks of brain hemorrhage. Bradykinin (BK) is well known for its actions as an endothelial-dependent vasodilator and a powerful proinflammatory agonist. A number of experimental studies have show that BK receptors are upregulated after stroke by mediating inflammatory effects during early stages after stroke, indicating that BK aggravates cerebral injury. In preliminary studies, we found that: 1) BK formation is increased after tPA therapy through plasma kallikrein activation; 2) co-administration of a BK receptor 2 antagonist with tPA treatment after stroke reduces hemorrhage transformation; 3) B2R agonist does not induce endothelial cell death during oxygen and glucose deprivation; 4) splenectomized or macrophage-depleted mice with tPA decreased brain hemorrhage; 5) BK infusion after stroke increases hemorrhage transformation, which was blocked in macrophage-depleted mice. The objective of the proposed studies is to define the mechanisms by which BK affects and activates macrophages after tPA therapy, thus causing brain hemorrhage via proinflammatory processes during vascular injury. Our ultimate goal is to delineate the mechanistic underpinnings of tPA therapy responsible for improving the time window and to render tPA safer and more widely usable in patients with stroke. We propose to test the following specific aims: (i) to determine the contribution of conditional endothelium- and macrophage-specific B2R deletion to tPA-induced hemorrhage transformation; (ii) to characterize the role of BK in activated macrophages on accumulation and recruitment after tPA treatment; (iii) to delineate the molecular mechanisms by which BK regulates macrophage function and its interaction with brain endothelial cells. I will use this mentored career development award (K01) to fulfill a series of training objectives, which build upon my prior skills in neuroscience, but also expand my expertise in ways, which are essential to my transition to independent investigator. The training component of this application will build on my expertise in the immune system by investigating vascular injury involved in brain hemorrhage after tPA therapy. Together with training in molecular immunobiology, this will enable me to establish my own cutting-edge research program in stroke. The career development activities will be mentored by Dr. George King in collaboration with Drs. Magdy Selim, Kazuhide Hawakaya, and Stephan Kissler because of their areas of scientific expertise, and the technical and scientific advice that I stand to gain from our mentoring relationship. My career development activities will be focused on: 1) mentorship and guidance on laboratory management and organization; 2) the development and growth of my independent research program; 3) institutional responsibilities and fulfilling requirements for promotion and expanding my scientific network; 4) grant writing skills.