ROS in Intermittent Hypoxia-Mediated Neuronal Cell Death

描述(申请人提供)：最近人们认识到，慢性间歇性低氧(IH)，如发生在人类阻塞性睡眠呼吸暂停(OSA)中，与严重的皮质-海马区损伤有关，并导致神经行为功能障碍。目前研究应用的目的是阐明活性氧自由基(ROS)和抗氧化酶在调控和预防慢性IH介导的神经细胞脆弱性中的分子机制。目前应用的工作假设是，IH期间氧的周期性振荡模拟了缺血(缺氧)/复氧过程，并可能增加细胞ROS的产生。氧化繁殖造成的累积损伤可能导致神经功能障碍。另一方面，靶向提高抗氧化酶活性可能会减少ROS介导的增殖，减少IH介导的皮质神经细胞死亡，并防止神经行为损伤。因此，这项建议将集中于以下特定目标：(1)鉴定IH介导的皮层神经细胞特定细胞间隔的特异性ROS产生，并分析线粒体、胞浆和细胞膜中与神经细胞脆弱性相关的特异性氧化还原变化。(2)通过细胞培养和小鼠模型，分析ROS介导的慢性IH诱导神经细胞死亡的分子过程，揭示神经细胞死亡的信号转导途径。(3)明确慢性IH介导的ROS产生、蛋白质聚集和神经细胞易损性之间的分子关系。具体地说，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调节慢性IH介导的神经细胞死亡中的作用。(4)。目的：研究线粒体锰超氧化物歧化酶(MnSOD)和磷脂谷胱甘肽过氧化物酶(Gpx4)在体外和体内原代神经细胞对慢性高压氧(IH)暴露的保护作用。具体地说，我们将使用基因转移、反义和转基因小鼠的方法来分析线粒体抗氧化活性增加/减少在预防/促进慢性IH介导的皮质神经细胞死亡中的作用。我们预计，对周期性低氧下神经元易感性机制的深入了解将导致制定有效的干预策略，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疾病。

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.