Viral Protein R (Vpr) in HIV-associated Brain Neuroinflammation and Neurotoxicity

病毒蛋白 R (Vpr) 在 HIV 相关脑神经炎症和神经毒性中的作用

• 批准号: 9890841
• 负责人: J. Marc Simard
• 金额: --
• 依托单位: BALTIMORE VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-07-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9890841
• 关键词: AIDS/HIV problem; Address; Affect; Aging; Antiviral Therapy; Apoptosis; Astrocytes; Autopsy; Binding; Biochemical; Blood - brain barrier anatomy; Brain; Brain Injuries; Cations; Cell Line; Cells; Central Nervous System Infections; Chronic; Data; Delirium; Dementia; Extracellular Space; FDA approved; Genetic; Genetic Transcription; Glyburide; Goals; HIV; HIV-1; HIV-associated neurocognitive disorder; Healthcare; Human; Immune; Individual; Infection; International; Knockout Mice; Lead; Link; Longevity; Mediating; Mental Depression; Mental Health; Methods; Microglia; Molecular; Mus; NF-kappa B; Neuraxis; Neurocognitive; Neurocognitive Deficit; Neuroglia; Neurologic; Neurons; Neuropathogenesis; Neuroregulator; Neurotoxins; Patients; Persons; Pharmaceutical Preparations; Pharmacology; Pilot Projects; Play; Proteins; Reporting; Research Priority; Residual state; Role; Severities; Source; Suicide; Surgeon; TLR4 gene; TNF gene; Testing; Therapeutic; Time; Transgenic Mice; Transgenic Organisms; Veterans; Viral; Viral Load result; Viral Proteins; Virion; Virus; Virus Replication; antiretroviral therapy; brain tissue; chemokine; cytokine; experience; glial activation; improved; insight; macrophage; neurocognitive disorder; neuroinflammation; neuron apoptosis; neurotoxic; neurotoxicity; novel; particle; promoter; reactivation from latency; response; suicidal risk; suicide mortality; virology; virus host interaction; vpr Gene Products

This proposed project has direct relevance to Veteran healthcare because it addresses current VA’s research priority on how HIV-1 infection causes brain damages that affect Veteran’s mental health including HIV- associated neurocognitive disorders (HAND) and suicide. There are about 37 million people currently living with HIV/AIDS worldwide. Successful treatment with combinational antiretroviral therapies (cART) can eliminate active replicating viruses and prolong patients’ lives to nearly normal lifespans. However, the new challenge faced by more than half of those HIV-infected and aging patients is the chronic CNS neuroinflammation, which leads to various HAND. While severe and progressive HAND has decreased significantly due to cART, chronic HANDS often persists, resulting in high rates of delirium, dementia and depression that could lead to suicide. Indeed, “the risk of suicide mortality in HIV-infected persons is 3-5 times higher than in HIV-uninfected counterparts”. Nevertheless, the mechanism of neuropathogenesis underlying HAND is not well understood. HAND is typically characterized by HIV-mediated glial neuroinflammation and neurotoxicity. Interestingly, the severity of some HAND does not always directly correlate with the levels of HIV, but rather with glial activation, suggesting other HIV-associated factors, not the whole virus per se, contribute to those HAND. HIV-1 viral protein R (Vpr) might be one of those viral factors, because Vpr induces neuroinflammation and causes neuronal apoptosis. Moreover, in the absence of active viral replication under cART, Vpr can be found in CNS-associated cells because 1) it can be released directly from viral particles; 2) it crosses the blood-brain barrier that can be taken up by glia and neurons; and 3) it triggers viral transcription of latently-infected cells by binding to LTR promoter. Despite these strong evidences indicating a prominent role of Vpr in HAND, how exactly Vpr contributes to HAND remains elusive. The objective of this proposal is to study the specific role(s) of Vpr in activation of host neuroinflammation, neurotoxicity and viral reactivation, as well as its contribution to HAND. Through our pilot studies, we discovered correlations between HIV expression and activation of proinflammatory markers (TLR4, TNFα, NF-κB and the Sur1-Trpm4 channel) in astrocytes of HIV-infected postmortem human and transgenic mouse brain tissues. Furthermore, Vpr alone activate the same set of markers in glial cells. The connection between Vpr and the Sur1-Trpm4 channel could potentially be significant for understanding HAND because this channel is a key neuro-regulator involved in various neurocognitive brain conditions. Indeed, inhibition of the channel by a repurposed and FDA-approved drug glibenclamide reduces Vpr-induced apoptosis and improves other neuroinflammatory brain conditions. Thus, our pilot studies may have revealed a novel mechanism of HAND involving Vpr-induced activation of the Sur1-Trpm4 channel. Therefore, we hypothesize that Vpr contributes to HAND by TLR4/MyD88- and/or TNFα-mediated NF-κB activation, which in turn upregulate the Sur1-Trpm4 channel leading to neuroinflammation and neurotoxicity. Alternatively, Vpr- induced HAND is contributed collectively by NF-κB and Sur1-Trpm4-mediated neuropathologic effects. We further hypothesize that target-specific inhibition of key regulators such as the Sur1-Trpm4 channel mitigates Vpr-induced HAND. We will test these hypotheses with three specific aims (SA). SA1: delineate molecular mechanism of Vpr-induced neuroinflammation, neurotoxicity and viral reactivation in primary astrocytes; SA2: test the functional link of Vpr with the Sur1-Trpm4 channel, its interaction with NF-kB and its contribution to Vpr- induced HAND; and SA3: evaluate the effects of genetic and pharmacologic inhibitions of the Sur1-Trpm4 channel on Vpr-induced HAND by using knock-out mice and by target-specific therapeutic drugs such as glibenclamide. Successful completion of this project will provide novel insights into 1) the molecular mechanism and contribution of HIV-1 Vpr to HAND, 2) the functional link between Vpr and the Sur1-Trpm4 channel and its contribution to HAND, and 3) the feasibility of treating Vpr-related HAND with the therapeutic drug glibenclamide.

该拟议项目与退伍军人医疗保健直接相关，因为它涉及退伍军人管理局当前的研究 优先关注 HIV-1 感染如何导致脑损伤，从而影响退伍军人的心理健康，包括 HIV- 相关的神经认知障碍（HAND）和自杀。目前约有 3700 万人生活在 全世界艾滋病毒/艾滋病。联合抗逆转录病毒疗法 (cART) 的成功治疗可以消除 活跃复制病毒并将患者的生命延长至接近正常的寿命。然而，新的挑战 超过一半的艾滋病毒感染者和老年患者面临的是慢性中枢神经系统炎症， 导致各种HAND。虽然由于 cART，严重和进行性 HAND 已显着减少，但慢性 手经常持续存在，导致谵妄、痴呆和抑郁症的发生率很高，甚至可能导致自杀。 事实上，“艾滋病毒感染者的自杀死亡风险比未感染艾滋病毒的人高 3-5 倍” 然而，HAND 的神经发病机制尚不清楚。 HAND 的典型特征是 HIV 介导的神经胶质神经炎症和神经毒性。有趣的是， 某些 HAND 的严重程度并不总是与 HIV 水平直接相关，而是与神经胶质激活相关， 表明其他与艾滋病毒相关的因素，而不是整个病毒本身，导致了这些 HAND。 HIV-1病毒蛋白 R (Vpr) 可能是这些病毒因子之一，因为 Vpr 会诱发神经炎症并导致神经元 细胞凋亡。此外，在 cART 下缺乏活跃的病毒复制的情况下，Vpr 可以在中枢神经系统相关的细胞中发现。 细胞，因为1）它可以直接从病毒颗粒中释放出来； 2）它可以穿过血脑屏障 被神经胶质细胞和神经元吸收； 3) 通过与 LTR 结合触发潜伏感染细胞的病毒转录 发起人。尽管这些强有力的证据表明 Vpr 在 HAND 中发挥着重要作用，但 Vpr 究竟如何发挥作用？ 对 HAND 的贡献仍然难以捉摸。本提案的目的是研究 Vpr 在以下方面的具体作用： 宿主神经炎症、神经毒性和病毒再激活的激活及其对 HAND 的贡献。 通过我们的试点研究，我们发现了 HIV 表达和激活之间的相关性 HIV 感染的星形胶质细胞中的促炎标记物（TLR4、TNFα、NF-κB 和 Sur1-Trpm4 通道） 死后人类和转基因小鼠脑组织。此外，Vpr 单独激活同一组 神经胶质细胞中的标记。 Vpr 和 Sur1-Trpm4 通道之间的联系可能很重要 用于理解 HAND，因为该通道是参与大脑各种神经认知的关键神经调节器 状况。事实上，FDA 批准的药物格列本脲对通道的抑制作用可降低 Vpr 诱导细胞凋亡并改善其他神经炎症性脑部疾病。因此，我们的试点研究可能有 揭示了 HAND 的一种新机制，涉及 Vpr 诱导的 Sur1-Trpm4 通道激活。所以， 我们假设 Vpr 通过 TLR4/MyD88 和/或 TNFα 介导的 NF-κB 激活来促进 HAND，这 反过来上调 Sur1-Trpm4 通道，导致神经炎症和神经毒性。或者，Vpr- 诱导的 HAND 是由 NF-κB 和 Sur1-Trpm4 介导的神经病理学效应共同促成的。我们 进一步假设关键调节因子（如 Sur1-Trpm4 通道）的目标特异性抑制可减轻 Vpr 诱导的手。我们将通过三个具体目标（SA）来检验这些假设。 SA1：描绘分子 Vpr诱导原代星形胶质细胞神经炎症、神经毒性和病毒再激活的机制； SA2： 测试 Vpr 与 Sur1-Trpm4 通道的功能联系、其与 NF-kB 的相互作用及其对 Vpr- 的贡献 诱发手；和 SA3：评估 Sur1-Trpm4 的遗传和药理抑制作用 通过使用基因敲除小鼠和目标特异性治疗药物（例如 格列本脲。该项目的成功完成将为1）分子机制提供新的见解 以及 HIV-1 Vpr 对 HAND 的贡献，2) Vpr 和 Sur1-Trpm4 通道之间的功能联系及其 对 HAND 的贡献，以及 3）用治疗药物格列本脲治疗 Vpr 相关 HAND 的可行性。