Role of miR-124 in HIV-1 Tat & cocaine mediated microglial activation

miR-124 在 HIV-1 Tat 中的作用

基本信息

批准号：
9411435
负责人：
Palsamy Periyasamy
金额：
$ 7.58万
依托单位：
UNIVERSITY OF NEBRASKA MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-07-01 至 2019-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9411435
关键词：
Animal Model Anti-Retroviral Agents Area Biological Assay Brain Cell Culture Techniques Cell Line Cells Cocaine Cocaine Abuse Comorbidity DNA Methylation Data Disease Down-Regulation Drug abuse Enzyme-Linked Immunosorbent Assay Epigenetic Process Exhibits Future Gene Expression Profile Genetic Transcription Global Change Goals HIV HIV Envelope Protein gp120 HIV-1 HIV-associated neurocognitive disorder Health Immunoprecipitation In Vitro Individual Infection Inflammation Inflammatory Interleukin-1 beta Interleukin-6 Lead Life Expectancy Link Luciferases Macaca mulatta Mediating Methyl-CpG-Binding Protein 2 Methylation MicroRNAs Microglia Modeling Modification Molecular Molecular Profiling Mus Neurodegenerative Disorders Neuroglia Neurons Newborn Infant Pathogenesis Pathway interactions Pharmaceutical Preparations Pharmacology Plasma Prevalence Process Proteins Public Health Regulation Research Role SIV STAT3 gene Signal Transduction Societies Substance abuse problem TNF gene Testing Tissues Trans-Activators Transfection Up-Regulation Validation Viral Proteins Viremia Western Blotting antiretroviral therapy cohort cytokine drug of abuse genetic approach glial activation lymph nodes neuroinflammation overexpression promoter pup sex symptomatology therapeutic development therapeutic target therapy adherence therapy development virus envelope

项目摘要

Project Summary Although the advent of combination antiretroviral therapy (cART) has dramatically increased the life expectancy of people living with HIV-1, paradoxically the prevalence of HIV-1-associated neurocognitive disorders (HAND) in people treated with cART, is on the rise. It is estimated that almost 30-60% of infected individuals on cART will go on to develop HAND, out of which at least 30% will have a co-morbidity of substance abuse. It is well recognized that HIV-1 infection and drug abuse go hand in hand, leading not only to compromised cART adherence but also to exacerbation of HAND. Drugs of abuse and HIV-1 viral proteins (transactivator of transcription - Tat & gp120) have been shown to accelerate HAND pathogenesis co- operatively. Furthermore, similar to HIV-1-positive subjects on cART, SIV-infected rhesus macaques on cART also exhibit increased glial activation, which was associated with dysregulation of various signature microRNAs (miRs). Emerging evidence also points to the role of drugs such as cocaine in mediating glial activation with global changes in miRs. In our preliminary studies, we have demonstrated that exposure of microglial cells to both Tat & cocaine resulted in increased activation of microglia (compared to cells exposed to either agent alone) and this, in turn, was associated with downregulation of brain-enriched miR-124 through an epigenetic pathway (miR-124 promoter DNA methylation) and a concomitant upregulation of MeCP2 (also p-MeCP2), and STAT3 - the predicted targets of miR-124. Furthermore, we also found that overexpression of miR-124 in microglia resulted in alleviation of Tat & cocaine-mediated activation of microglia. The premise of this proposal is that the effect of HIV-1 Tat and cocaine can lead to increased activation of microglia, thereby serving as a model for assessment of broader effects of these agents in the CNS. It is thus hypothesized that Tat & cocaine activate microglia via downregulation of miR-124 involving the unique MeCP2-STAT3 signaling axis. The hypothesis will be tested in two specific aims: AIM 1: Determine the epigenetic mechanism(s) underlying Tat &/or cocaine-mediated downregulation of miR-124 and its association with microglial activation in vitro. AIM 2: Determine the effect(s) of miR-124 overexpression in blocking Tat &/or cocaine-mediated induction of Mg activation in vitro. The findings from this study will set the stage for our long- term future goals (not a part of this study), of validating the cell culture findings in appropriate animal models of HAND & cocaine abuse, and of harnessing the epigenetic modifications associated with Tat & cocaine-induced CNS inflammation as therapeutic targets of HAND.

项目概要尽管联合抗逆转录病毒疗法 (cART) 的出现极大地延长了患者的寿命 HIV-1 感染者的预期，矛盾的是 HIV-1 相关神经认知的患病率接受 cART 治疗的患者中的疾病 (HAND) 呈上升趋势。据估计，近 30-60% 的感染者接受 cART 的个体将继续发展为手部疾病，其中至少 30% 的人会患有以下并发症：药物滥用。众所周知，HIV-1 感染与药物滥用密切相关，不仅导致损害了 cART 的依从性，而且还会加剧 HAND。滥用药物和 HIV-1 病毒蛋白（转录反式激活因子 - Tat 和 gp120）已被证明可加速 HAND 发病机制可操作地。此外，与 cART 上的 HIV-1 阳性受试者类似，cART 上感染 SIV 的恒河猴还表现出神经胶质细胞活化增加，这与各种特征性 microRNA 的失调有关（miR）。新出现的证据还指出可卡因等药物在介导神经胶质细胞活化中的作用 miR 的全局变化。在我们的初步研究中，我们已经证明小胶质细胞暴露于 Tat 和可卡因均导致小胶质细胞活化增加（与暴露于任一药物的细胞相比）单独），而这又与通过表观遗传下调大脑富集的 miR-124 相关。途径（miR-124 启动子 DNA 甲基化）和 MeCP2（也称为 p-MeCP2）的伴随上调，以及 STAT3 - miR-124 的预测靶标。此外，我们还发现miR-124在小胶质细胞导致了 Tat 和可卡因介导的小胶质细胞激活的减轻。这样做的前提是该提议认为，HIV-1 Tat 和可卡因的作用可以导致小胶质细胞的激活增加，从而作为评估这些药物在中枢神经系统中更广泛影响的模型。因此假设 Tat 和可卡因通过下调涉及独特 MeCP2-STAT3 的 miR-124 激活小胶质细胞信号轴。该假设将在两个具体目标上进行检验：目标 1：确定表观遗传 Tat 和/或可卡因介导的 miR-124 下调的机制及其与小胶质细胞体外激活。目标 2：确定 miR-124 过表达在阻断 Tat 和/或可卡因介导的体外镁激活诱导。这项研究的结果将为我们的长期研究奠定基础术语未来目标（不是本研究的一部分），即在适当的动物模型中验证细胞培养结果 HAND 和可卡因滥用，以及利用与 Tat 和可卡因诱导相关的表观遗传修饰中枢神经系统炎症作为 HAND 的治疗靶点。