Masvekar Ruturaj R, El-Hage Nazira, Hauser Kurt F, Knapp Pamela E
Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, Virginia, United States of America.
Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, United States of America.
PLoS One. 2014 Jun 20;9(6):e100196. doi: 10.1371/journal.pone.0100196. eCollection 2014.
HIV-1 enters the CNS soon after initial systemic infection; within the CNS parenchyma infected and/or activated perivascular macrophages, microglia and astrocytes release viral and cellular toxins that drive secondary toxicity in neurons and other cell types. Our previous work has largely modeled HIV-neuropathology using the individual viral proteins Tat or gp120, with murine striatal neurons as targets. To model disease processes more closely, the current study uses supernatant from HIV-1-infected cells. Supernatant from HIV-1SF162-infected differentiated-U937 cells (HIV+sup) was collected and p24 level was measured by ELISA to assess the infection. Injection drug abuse is a significant risk factor for HIV-infection, and opiate drug abusers show increased HIV-neuropathology, even with anti-retroviral treatments. We therefore assessed HIV+sup effects on neuronal survival and neurite growth/pruning with or without concurrent exposure to morphine, an opiate that preferentially acts through µ-opioid receptors. Effects of HIV+sup ± morphine were assessed on neuronal populations, and also by time-lapse imaging of individual cells. HIV+sup caused dose-dependent toxicity over a range of p24 levels (10-500 pg/ml). Significant interactions occurred with morphine at lower p24 levels (10 and 25 pg/ml), and GSK3β was implicated as a point of convergence. In the presence of glia, selective neurotoxic measures were significantly enhanced and interactions with morphine were also augmented, perhaps related to a decreased level of BDNF. Importantly, the arrest of neurite growth that occurred with exposure to HIV+sup was reversible unless neurons were continuously exposed to morphine. Thus, while reducing HIV-infection levels may be protective, ongoing exposure to opiates may limit recovery. Opiate interactions observed in this HIV-infective environment were similar, though not entirely concordant, with Tat/gp120 interactions reported previously, suggesting unique interactions with virions or other viral or cellular proteins released by infected and/or activated cells.
HIV-1在初次全身性感染后不久即进入中枢神经系统；在中枢神经系统实质内，被感染和/或被激活的血管周围巨噬细胞、小胶质细胞和星形胶质细胞会释放病毒毒素和细胞毒素，从而对神经元和其他细胞类型产生继发性毒性。我们之前的工作主要使用单个病毒蛋白Tat或gp120，以小鼠纹状体神经元为靶点，对HIV神经病理学进行建模。为了更紧密地模拟疾病过程，当前研究使用了来自HIV-1感染细胞的上清液。收集来自HIV-1 SF162感染的分化U937细胞的上清液（HIV+sup），并通过ELISA测量p24水平以评估感染情况。注射吸毒是HIV感染的一个重要危险因素，阿片类药物滥用者即使接受抗逆转录病毒治疗，其HIV神经病理学表现也会加重。因此，我们评估了HIV+sup对神经元存活以及神经突生长/修剪的影响，同时评估了是否同时暴露于吗啡（一种主要通过μ-阿片受体起作用的阿片类药物）的情况。评估了HIV+sup±吗啡对神经元群体的影响，以及对单个细胞的延时成像影响。在一系列p24水平（10 - 500 pg/ml）范围内，HIV+sup会引起剂量依赖性毒性。在较低的p24水平（10和25 pg/ml）下，与吗啡发生了显著的相互作用，并且GSK3β被认为是一个交汇点。在有神经胶质细胞存在的情况下，选择性神经毒性指标显著增强，与吗啡的相互作用也增强，这可能与脑源性神经营养因子（BDNF）水平降低有关。重要的是，除非神经元持续暴露于吗啡，否则暴露于HIV+sup时发生的神经突生长停滞是可逆的。因此，虽然降低HIV感染水平可能具有保护作用，但持续暴露于阿片类药物可能会限制恢复。在这种HIV感染环境中观察到的阿片类药物相互作用与先前报道的Tat/gp120相互作用相似，但并不完全一致，这表明与病毒粒子或被感染和/或被激活细胞释放的其他病毒或细胞蛋白存在独特的相互作用。
