ROS in Intermittent Hypoxia-Mediated Neuronal Cell Death

描述（由申请人提供）：最近已经认识到，慢性间歇性缺氧（IH），如发生在人阻塞性睡眠呼吸暂停（OSA）中，与实质性皮质-海马损伤相关，并导致神经行为功能障碍。目前的研究应用的目的是描绘的分子机制的活性氧（ROS）和抗氧化酶的调制和预防慢性IH介导的神经细胞的脆弱性。本申请的工作假设是IH期间氧的周期性振荡模拟缺血（缺氧）/再氧合过程，并且可以增加细胞ROS产生。氧化传播的累积损伤可能导致神经功能障碍。另一方面，有针对性地增加抗氧化酶活性可以减少ROS介导的增殖，减少IH介导的皮层神经元细胞死亡，并防止神经行为障碍。因此，该提案将重点关注以下具体目标：（1）鉴定皮质神经元细胞特定细胞区室中IH介导的特定活性氧产生，并分析线粒体、胞质溶胶和膜中特定的氧化还原变化，因为它们与神经元细胞的脆弱性有关。(2)分析慢性IH诱导的ROS介导的神经元细胞死亡的分子过程，并利用细胞培养和小鼠模型描述神经元细胞死亡的信号转导途径。(3)确定慢性IH介导的ROS产生、蛋白质聚集和神经细胞脆弱性之间的分子关系。具体而言，我们将使用原代细胞培养和啮齿动物模型来阐明蛋白质氧化和蛋白质聚集在慢性IH介导的神经元细胞死亡的调制中的作用。（四）、目的：研究线粒体MnSOD和磷脂谷胱甘肽过氧化物酶（GPX 4）在体外和体内对慢性IH暴露的原代神经细胞的保护作用。具体来说，我们将使用基因转移，反义和转基因小鼠的方法来分析增加/减少线粒体抗氧化活性的影响，在预防/促进慢性IH介导的皮层神经元细胞死亡。我们预计，增加对神经元对周期性缺氧的脆弱性的机制的理解，将导致有效的干预策略的描绘，旨在减少与阻塞性睡眠呼吸暂停相关的大量神经认知和行为发病率。

DESCRIPTION (provided by applicant): It has been recently recognized that chronic intermittent hypoxia (IH), as occurs in human obstructive sleep apnea (OSA), is associated with substantial cortico-hippocampal damage and leads to impairments in neurobehavioral functions. The objective of the current research application is to delineate the molecular mechanisms of reactive oxygen species (ROS) and antioxidant enzymes in the modulation and prevention of chronic IH-mediated neuronal cell vulnerability. The working hypothesis of the current application is that the cyclical oscillations of oxygen during IH mimics the ischemia (hypoxia)/re-oxygenation process and may increase cellular ROS production. The cumulative damage from oxidative propagation may result in neurological dysfunction. On the other hand, targeted increases in antioxidant enzymatic activity may reduce ROS-mediated propagation, decrease IH-mediated cortical neuronal cell death and prevent the neurobehavioral impairments. This proposal will therefore focus on the following specific aims: (1) To identify IH-mediated specific ROS production at specific cellular compartments of cortical neuronal cells and analyze the specific redox alterations in mitochondria, cytosol and membrane as they relate to neuronal cell vulnerability. (2) To analyze the molecular processes of ROS-mediated neuronal cell death induced by chronic IH, and delineate signal transduction pathways underlying neuronal cell death using cell culture and mouse models. (3) To define molecular relationships between chronic IH-mediated ROS production, protein aggregation, and neuronal cell vulnerability. Specifically, we will use primary cell culture and rodent models to elucidate the roles of protein oxidation and protein aggregation in the modulation of chronic IH-mediated neuronal cell death. (4). To study the protective roles of mitochondrial MnSOD and phospholipid glutathione peroxidase (GPX4) in primary neuronal cells in vitro and in vivo in response to chronic IH exposures. Specifically, we will use gene transfer, anti-sense, and transgenic mouse approaches to analyze the effects of increased/decreased mitochondrial anti-oxidant activity in preventing/facilitating chronic IH-mediated cortical neuronal cell death. We anticipate that increased understanding of the mechanisms underlying neuronal vulnerability to cyclical hypoxia will lead to delineation of effective interventional strategies aiming to reduce the substantial neurocognitive and behavioral morbidities associated with obstructive sleep apnea.