ROLE OF MITOCHONDRIAL-PRODUCED ROS IN NEUROGENIC HYPERTENSION

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 脑血管紧张素II（AngII）信号传导的失调与心血管疾病（包括心力衰竭和高血压）的发病机制有关。血管紧张素II循环水平的增加可通过作用于称为室周器官的专门脑区（其缺乏血脑屏障）并改变中枢心血管输出（包括交感神经兴奋、血管加压素释放和压力反射抑制）而导致神经源性高血压的发展。为了更好地了解AngII在神经源性高血压发展中的中枢作用，并确定新的中枢治疗靶点，研究AngII在中枢神经系统（CNS）中的信号传导机制是至关重要的。以前，活性氧（ROS）产生的NADPH氧化酶已被确定为重要的信号中间体在中央血管紧张素II介导的心血管效应。尽管NADPH氧化酶已被证明是ROS的关键来源，但包括线粒体在内的其他来源（其是大多数细胞中ROS产生的主要位点）尚未被研究。在此，我们提出了一系列体外分子生物学和生物化学研究以及体内综合性心血管生理学实验来验证新的假设，即脑内产生的ROS在脑血管紧张素能信号传导中起着重要作用，并且在CNS心血管控制区域过度表达脑内靶向抗氧化剂可改善神经源性高血压。使用CNS衍生的原代神经元，以及AngII敏感的神经元细胞培养模型，我们将在AngII刺激后特异性地测量线粒体中的ROS水平。此外，我们将使用腺病毒介导的靶向抗氧化剂的神经元的基因转移，以检查神经元产生的ROS的影响，血管紧张素II在神经元中的变时作用，使用电生理技术。最后，使用实验小鼠模型血管紧张素II依赖性神经源性高血压，我们将确定在疾病的发病机制中的中枢神经系统中的神经系统产生的ROS的作用。这些研究将为AngII的神经元内信号传导机制提供新的信息，并可能将脑内产生的ROS确定为神经源性高血压的重要治疗靶点。 心脏衰竭和高血压是两种与大脑异常刺激相关的心血管疾病。自由基和氧化剂产生的脑细胞称为神经元已被证明是参与这些心血管疾病。这项研究的主要目标是使用在特定细胞位置（线粒体）中发现的抗氧化剂来预防高血压的发展。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Dysregulation of brain angiotensin II (AngII) signaling is implicated in the pathogenesis of cardiovascular diseases, including heart failure and hypertension. Increased circulating levels of AngII can lead to the development of neurogenic hypertension by acting on specialized brain regions known as circumventricular organs, which lack a blood-brain-barrier, and altering central cardiovascular outputs including sympathoexcitation, release of vasopressin, and dampening of baroreflexes. To better understand the central actions of AngII in the development of neurogenic hypertension and to identify novel, central therapeutic targets of the disease, it is essential to investigate the signaling mechanisms of AngII in the central nervous system (CNS). Previously, reactive oxygen species (ROS) generated by NADPH oxidase have been identified as important signaling intermediates in central AngII-mediated cardiovascular effects. Although NADPH oxidase has been shown to be a critical source of ROS, additional sources including mitochondria, which are the primary sites for ROS generation in most cells, have yet to be investigated. Herein, we propose a series of in vitro molecular biological and biochemical studies and in vivo integrative cardiovascular physiological experiments to test the novel hypothesis that mitochondrial-produced ROS play a fundamental role in brain angiotensinergic signaling, and that overexpression of mitochondrial-targeted antioxidants in CNS cardiovascular control regions ameliorates neurogenic hypertension. Using CNS-derived primary neurons, as well as an AngII-sensitive neuronal cell culture model we will measure ROS levels specifically in mitochondria following AngII stimulation. In addition, we will use adenoviral-mediated gene transfer of mitochondrial-targeted antioxidants to examine the effects of mitochondrial-produced ROS on the chronotropic action of AngII in neurons using electrophysiological techniques. Finally, using an experimental mouse model of AngII-dependent neurogenic hypertension we will determine the role of mitochondrial-produced ROS in the CNS in the pathogenesis of the disease. These studies will provide new information on the intra-neuronal signaling mechanisms of AngII, and may identify mitochondrial-produced ROS as important therapeutic targets in neurogenic hypertension. Lay Description: Heart failure and hypertension are two cardiovascular diseases associated with abnormal stimulation in the brain. Free radicals and oxidants produced in brain cells called neurons have been shown to be involved in these cardiovascular diseases. The primary goal of this study is to use antioxidants, which are found in a specific cellular location (mitochondria), to prevent the development of hypertension.