Stress Granule Formation in the Antiretroviral-Mediated Dysregulation of Oligodendrocyte Maturation in HIV-HAND

项目总结 大约一半的艾滋病毒携带者(PWH)会经历与艾滋病毒相关的神经认知障碍(HAND)， 并呈现为一系列神经认知障碍。而美国的大多数威尔斯亲王医院是 病毒被抑制或检测不到，出现手部症状的PWH的总体比例保持不变 保持不变。手部的特征之一是白质的萎缩，这是一种持续存在于手部的病理 接受抗逆转录病毒治疗的患者。在威斯康星医院接受抗逆转录病毒治疗的持续时间已被证明与观察到的 白质的丢失，导致了人们对药物本身导致这种病理的担忧。衰减率 白质的减少与髓鞘的丧失有关，在中枢神经系统中，髓鞘是由少突胶质细胞(OL)产生的。 髓鞘是跳跃性传导和轴突营养支持所必需的，它的丢失可能导致 手头出现的临床变化。我们实验室以前的工作已经证明，精选的抗逆转录病毒药物可以预防 少突胶质细胞的成熟和髓鞘形成，尽管这些观察背后的机制需要 额外的调查。我们进一步表明，用精选的抗逆转录病毒药物治疗成熟的OL，例如 Elvitegravir(EVG)，激活综合应激反应(ISR)，抑制ISR使OL恢复 在EVG存在的情况下分化。ISR是用于恢复真核生物体内平衡的适应性途径 细胞在应激条件下，有时以细胞质应激颗粒的形成为特征 (SGS)，被认为有助于全球抑制翻译的无膜细胞器。应激颗粒没有 但在少突胶质细胞中被广泛研究，但对其他神经退行性疾病的研究发现 它们在神经元中的存在可能会导致神经变性的加速。在慢性压力下，SGS可以 变得持久，mRNAs和蛋白质的长期聚集可能成为病理性的。的确有 与肌萎缩侧索硬化症(ALS)相关的神经元慢性SG积聚的有力证据， 阿尔茨海默氏症和额颞部痴呆。我们的实验室还在HIV+的死后白质中观察到了SGS 有神经认知障碍的患者。此外，我的初步数据显示，成熟的OL治疗 EVG不仅激活ISR，而且形成SGS，随着ISR的抑制而消失。我假设在此期间 ARV药物治疗，应激颗粒通过PERK激活隔离OLs成熟所需的mRNAs 这些颗粒的形成是为了防止细胞死亡。我将通过三个具体目标来检验这一假设。目标 1：我将确定ARV药物诱导的应激颗粒是否通过PERK激活的ISR形成OL。目标2：我会 确定在ARV药物暴露期间SG的形成对OL存活的贡献。目标3：我会决定 ARV诱导的OLS中的SGS是否需要成熟和髓鞘形成所需的mRNAs隔离。自压力以来 颗粒以前没有在少突胶质细胞中被表征，这项工作不仅提供了对 改善ART治疗PWH的结果，但也将有利于其他神经疾病的研究 以白质丢失为特征的。

PROJECT SUMMARY HIV-Associated Neurocognitive Disorder (HAND) is experienced by about half of people living with HIV (PWH), and presents as a spectrum of neurocognitive impairments. While the majority of PWH in the United States are virally suppressed or undetectable, the overall proportion of PWH with HAND symptoms has remained unchanged. One of the hallmarks of HAND is the atrophy of white matter, a pathology that persists in HAND patients treated with ART. The duration of ART treatment in PWH has been shown to correlate to the observed loss of white matter, leading to the concern that the drugs themselves are causing this pathology. The attenuation of white matter is associated with a loss of myelin, which in the CNS is produced by oligodendrocytes (OLs). Myelin is necessary for saltatory conduction and trophic support of axons and its loss may contribute to the clinical changes seen in HAND. Previous work from our lab has demonstrated that select ART drugs prevent the maturation of oligodendrocytes and myelination, though the mechanisms underlying these observations require additional investigation. We have further shown that treating maturing OLs with select ART drugs, such as Elvitegravir (EVG), activates the Integrated Stress Response (ISR), and inhibition of the ISR restores OL differentiation in the presence of EVG. The ISR is an adaptive pathway used to restore homeostasis in eukaryotic cells under stressful conditions, and is sometimes characterized by the formation of cytoplasmic stress granules (SGs), membraneless organelles thought to aid in the global inhibition of translation. Stress granules have not yet been extensively studied in oligodendrocytes, but research of other neurodegenerative diseases has found that their presence in neurons may cause acceleration of neurodegeneration. During chronic stress, SGs can become persistent, and the long-term aggregation of mRNAs and proteins can become pathological. There is strong evidence associating chronic SG accumulation in neurons with amyotrophic lateral sclerosis (ALS), Alzheimer’s, and frontotemporal dementia. Our lab has also observed SGs in post-mortem white matter of HIV+ patients with neurocognitive impairment. Furthermore, my preliminary data has shown that maturing OLs treated with EVG not only activate the ISR, but also form SGs that disappear with ISR inhibition. I hypothesize that during ARV drug treatment, stress granules sequester mRNAs needed for maturation of OLs via PERK activation of the ISR, and that these granules form to prevent cell death. I will test this hypothesis via three specific aims. AIM 1: I will determine if ARV Drug induced stress granules in OLs form via the PERK activated ISR. AIM 2: I will determine the contribution of SG formation to OL survival during ARV drug exposure. AIM 3: I will determine whether ARV-induced SGs in OLs sequester mRNAs needed for maturation and myelination. Since stress granules have not previously been characterized in oligodendrocytes, this work will not only provide insight into improving outcomes of ART treated PWH, but will also benefit research of other neurological diseases characterized by loss of white matter.