Effects of HIV- and ARV-Induced Oxidative Stress on Neuroglial Cells

描述：全世界有3300万人感染了艾滋病毒。获得性免疫缺陷综合症现在可以通过抗逆转录病毒（ARV）药物来避免，这种药物可以抑制病毒复制并恢复免疫系统功能。然而，50%的人患有某种形式的神经损伤，称为艾滋病毒相关的神经认知障碍（HAND）。氧化应激已被清楚地证明在患有HAND的个体的脑和脑脊髓液中，即使使用有效的ARV治疗。HIV和受感染巨噬细胞的分泌产物诱导氧化应激。此外，抗逆转录病毒化合物，在没有病毒感染的情况下，已显示产生ER和氧化应激，活性氧（ROS）和神经元损伤。抗逆转录病毒药物在神经元中诱导ROS，但在皮质神经胶质细胞培养中导致神经元毒性。这项工作的第一个目标是具体地证明神经元内源性抗氧化反应（ESTA）通路参与响应媒体从HIV感染的巨噬细胞和ARV。Nrf 2是负责转录的转录因子。将确定Nrf 2定位和效应蛋白转录和翻译，以及ROS水平。HAND中的白色物质病理在有效抑制病毒的时代更普遍。迄今为止，还没有研究检查ART对少突胶质细胞谱系细胞群的直接影响。虽然一项研究报告了在病毒蛋白gp 120存在下体外髓鞘形成的减少，但HIV感染的巨噬细胞的影响尚未得到表征。该提案的第二个目标是解决艾滋病毒和抗逆转录病毒化合物对成熟和发育中的少突胶质细胞的直接影响。将通过免疫荧光染色、探测mRNA和蛋白质水平以及细胞死亡测定来确定细胞形态、成熟和活力。将确定通过HIV/ART诱发的氧化应激是否改变这些细胞的成熟。在脑的所有细胞群中上调BRA可能是ART方案的有效补充。更高的内源性抗氧化活性将通过促进对氧化应激的防御来降低由病毒和ARV诱导的细胞ROS。本提案的最终目的是研究在氧化剂降解的情况下升高的Nrf 2活性水平的潜在保护作用。通过在神经胶质细胞和少突胶质细胞培养物中给予抗氧化剂富马酸单甲酯，可实现神经胶质细胞的上调。将HIV/ART毒性对这些培养物的影响与具有基础Nrf 2活性水平的那些进行比较。将测定ROS、氧化损伤和细胞死亡的水平。这项工作将提供一个了解Nrf 2通路的调节，以及特点的神经胶质细胞和少突胶质细胞培养系统。一旦理解，靶向调节可用于减弱氧化损伤和细胞死亡。将研究结果转化为体内环境将提供一种新的内源性治疗途径，以潜在地降低显示氧化应激证据的神经退行性疾病的严重程度或进展速度。

DESCRIPTION: 33 million individuals worldwide are infected with HIV. Acquired immunodeficiency syndrome is now staved off by antiretroviral (ARV) drugs which suppress viral replication and restore immune system function. However, 50% of individuals suffer from some form of neurological impairment, termed HIV-Associated Neurocognitive Disorder (HAND). Oxidative stress has been clearly demonstrated in the brain and cerebral spinal fluid of individuals suffering from HAND, even with effective ARV therapy. HIV and secreted products from infected macrophages induce oxidative stress. Additionally, antiretroviral compounds, in the absence of viral infection, have been shown to produce ER and oxidative stress, reactive oxygen species (ROS) and neuronal damage. ARV drugs induce ROS in neurons, yet result in neuronal toxicity in cortical neuroglial culture. The first goal of this work is to concretely demonstrate neuronal endogenous antioxidant response (EAR) pathway involvement in response to media from HIV-infected macrophages and ARVs. Nrf2 is the transcription factor responsible for the EAR. Nrf2 localization and effector protein transcription and translation will be determined, as will levels of ROS. White matter pathologies in HAND are more prevalent in the era of effective viral suppression. No studies to date have examined direct effects of ART on cell populations of the oligodendrocyte lineage. While a single study reported decreased in vitro myelination in the presence of viral protein gp120, the effects of HIV-infected macrophages have not been characterized. The second goal of this proposal will address the direct effects of HIV and antiretroviral compounds on mature and developing oligodendrocytes. Cellular morphology, maturation, and viability will be ascertained through immunofluorescent staining, probing for levels of mRNA and protein, and cell death assays. It will be determined if oxidative stress evoked through HIV/ART alters maturation of these cells. Upregulation of the EAR in all cell populations of the brain may be an effective adjunctive to ART regimens. Higher endogenous antioxidant activity would lower cellular ROS induced by the virus and ARVs by promoting defenses against oxidative stress. The final aim of this proposal will investigate the potential protective effects of elevated Nrf2 activity levels in the context of an oxidant challeng. EAR upregulation will be achieved through administration of the antioxidant monomethyl fumarate in neuroglial and oligodendrocyte culture. Effects of HIV/ART toxicity on these cultures will be compared to those with basal Nrf2 activity levels. Levels of ROS, oxidative damage, and cell death will be assayed. This work will provide an understanding of Nrf2 pathway regulation in well characterized neuroglial and oligodendrocyte culture systems. Once understood, targeted modulation can be utilized to attenuate oxidative damage and cell death. Translation of findings to an in vivo setting will provide a novel endogenous therapeutic avenue to potentially lessen severity or speed of progression of neurodegenerative diseases displaying evidence of oxidative stress.