Cellular and Molecular Physiology of Sympathetic Innervation of Vascular Smooth Muscle

血管平滑肌交感神经支配的细胞和分子生理学

• 批准号: RGPIN-2019-04925
• 负责人: Poburko, Damon
• 金额: $ 2.33万
• 依托单位: Simon Fraser University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=715235
• 关键词: Cellular; Molecular; Physiology; Sympathetic; Innervation

The goal of my NSERC research program is to understand control of blood pressure and blood flow through the body. Sympathetic nerves surrounding blood vessels cause contraction of vascular smooth muscle cells and reduce vessel diameter; if these nerves are over-active, they can cause high blood pressure, while their under-activity promotes fainting. In contrast to most brain nerve cells, which release one type of neurotransmitter (NT), sympathetic nerves “co-release” multiple NTs. Regulation of transmitter co-release is poorly understood at the molecular level. In the next five years, my NSERC research will explore three fundamental aspects of how sympathetic nerves store and release multiple NTs in order to address long-standing gaps in our understanding of sympathetic regulation of blood vessel diameter. Norepinephrine (NE) and ATP are the main NTs released onto blood vessels. Whether sympathetic nerves store NE and ATP in the same releasable vesicles or separate vesicles has been debated for 30 years. We recently reported compelling evidence that NE and ATP are stored in separate vesicles. In Objective 1, we will use advanced (super-resolution) microscopic and molecular methods to understand the molecular basis of separate NT storage and co-release. This work will clarify how these nerves respond to a wide range of physiological conditions. NT release requires calcium to enter nerve terminals through voltage-gated calcium channels from the CaV2 family. Different forms of these channels can be targeted to specific locations in cells and nerve terminals. Knowing which channels cause the release of one or more types of NT will help us to understand how one set of nerves can release different NTs in different situations. In Objective 2, we will determine which NTs are released by three channels (CaV2.1, CaV2.2 and CaV2.3) in differential vascular beds and cell culture models using novel imaging methods. Mitochondria are organelles best known for making ATP, but they also modulate localized calcium signals. We will study how these mitochondrial functions impact the release of NE and ATP from sympathetic nerves. In Objective 3, we will test if mitochondria differentially affect NE or ATP release, over physiological stimulation frequencies. These studies will improve our understanding of how the loss of mitochondria might affect sympathetic nerve function and smooth muscle regulation in aging blood vessels. The novelty of this research program lies in creatively using modern methods to address decades-old questions about NT co-release. Our research will enrich our knowledge of neural control of blood vessels and will be of immediate use to others studying NT co-release and help identify therapeutic targets for the treatment of hypertension. Researchers studying the brain and hormone secretion will benefit from our genetically encoded reporters, and microscopists will benefit from the image analysis algorithms and software that we create.

我的NSERC研究项目的目标是了解血压和血液流经身体的控制。血管周围的交感神经引起血管平滑肌细胞收缩并减小血管直径;如果这些神经过度活跃，它们会导致高血压，而它们的活动不足会导致昏厥。与大多数脑神经细胞释放一种类型的神经递质（NT）相反，交感神经“共同释放”多种NT。在分子水平上对递质共释放的调节知之甚少。在接下来的五年里，我的NSERC研究将探索交感神经如何储存和释放多个NT的三个基本方面，以解决我们对血管直径交感神经调节的理解长期存在的差距。 去甲肾上腺素（NE）和ATP是释放到血管上的主要NT。交感神经是否将NE和ATP储存在同一个可释放的囊泡或单独的囊泡中已经争论了30年。我们最近报道了令人信服的证据，NE和ATP储存在不同的囊泡。在目标1中，我们将使用先进的（超分辨率）显微镜和分子方法来了解单独的NT存储和共同释放的分子基础。这项工作将阐明这些神经如何对广泛的生理条件作出反应。 NT释放需要钙通过来自CaV 2家族的电压门控钙通道进入神经末梢。这些通道的不同形式可以靶向细胞和神经末梢中的特定位置。了解哪些通道导致一种或多种NT的释放将有助于我们了解一组神经如何在不同情况下释放不同的NT。在目标2中，我们将使用新的成像方法确定在差异血管床和细胞培养模型中由三个通道（CaV2.1、CaV2.2和CaV2.3）释放哪些NT。 线粒体是制造ATP的细胞器，但它们也调节局部钙信号。我们将研究这些线粒体功能如何影响交感神经释放NE和ATP。在目标3中，我们将测试线粒体是否在生理刺激频率上差异地影响NE或ATP释放。这些研究将提高我们对线粒体的丧失如何影响交感神经功能和衰老血管中平滑肌调节的理解。 这项研究计划的新奇在于创造性地使用现代方法来解决几十年来关于NT共同发布的问题。我们的研究将丰富我们对血管神经控制的知识，并将立即用于其他研究NT共释放，并帮助确定治疗高血压的治疗靶点。研究大脑和激素分泌的研究人员将受益于我们的基因编码报告，显微镜工作者将受益于我们创建的图像分析算法和软件。