Modulation of Sp1/Sp3 by HIV-1 Tat Contributes to oxidative stress in HIV-PAH

HIV-1 Tat 对 Sp1/Sp3 的调节有助于 HIV-PAH 的氧化应激

• 批准号: 8992878
• 负责人: ADELA COTA-GOMEZ
• 金额: $ 46.03万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-17 至 2019-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8992878
• 关键词: 3-nitrotyrosine; Acetylation; Acetylesterase; Acute; Address; Alveolar Macrophages; Animal Model; Animals; Anti-Retroviral Agents; Apoptosis; Arteries; Binding Sites; Biological; Biological Assay; Blood; Cardiac; Cell Culture Techniques; Cells; Chronic; Chronic Disease; Clinical; Deacetylase; Deacetylation; Diagnosis; Disease; Elements; Endothelial Cells; Epidemiology; Exposure to; Family; General Population; Genetic Transcription; Glutathione; HIV; HIV Infections; HIV tat Protein; HIV therapy; HIV-1; Heart Diseases; Hematopoietic stem cells; Histone Deacetylase Inhibitor; Human; Immune; Immune System Diseases; Implant; In Vitro; Indium; Individual; Infection; Inflammation; Inflammatory Response; Injury; Interleukin-2; Irrigation; Knockout Mice; Lead; Lipid Peroxides; Liver; Lung; Lung diseases; Manganese; Manganese Superoxide Dismutase; Measures; Mitochondria; Modeling; Molecular; Morbidity - disease rate; Mus; Nucleotides; Oxidants; Oxidative Stress; Pathogenesis; Patients; Peripheral Blood Mononuclear Cell; Pharmaceutical Preparations; Physiological; Play; Predisposition; Proteins; Pulmonary Hypertension; Pulmonary vessels; Regulation; Reporting; Repression; Research; Resistance; Role; Source; Sp1 Transcription Factor; Sp3 Transcription Factor; Specimen; Superoxide Dismutase; Superoxides; T-Lymphocyte; Thymic Tissue; Time; Tissues; Transcriptional Regulation; Transferase; Trichostatin A; Vascular remodeling; Viral; Viral Proteins; Virus Diseases; abstracting; antiretroviral therapy; combinatorial; fetal; in vivo; indexing; inhibitor/antagonist; mortality; mouse model; normotensive; novel; promoter; public health relevance; pulmonary arterial hypertension; pulmonary artery endothelial cell; receptor; research study; response; small hairpin RNA; tat Protein; tool; transcription factor

 DESCRIPTION (provided by applicant): Since the introduction of the highly active antiretroviral combinatorial therapies for HIV (HAART) the pathogenesis of HIV infection is now more commonly a chronic, long-term infection that has dramatically changed the epidemiology of this disease. Long-term exposure to low levels of viral replication has unmasked susceptibilities to a number of cardiac and pulmonary diseases that are now more common causes of morbidity and mortality. For example, HIV-associated pulmonary arterial hypertension (HIV-PAH) PAH is approximately 25 times more prevalent among HIV infected individuals than in the general population. We have found that the HIV Tat protein promotes a number of pro-oxidative and pro-inflammatory responses that are not directly related to its function as a viral transcriptional regulator. For example, we and others have demonstrated that Tat induces oxidative stress via depletion of glutathione and alteration of manganese- dependent superoxide dismutase (MnSOD). In endothelial cells, the resultant increase in oxidants can promote a number of physiological responses such as inflammation, apoptosis and subsequent proliferation of apoptosis-resistant cells that can contribute to the occlusion of pulmonary vessels. Thus, we propose that Tat- induced oxidative stress has a central role in initiating the pathogenic cascade that ultimate leads to pulmonary vascular remodeling in HIV-PAH. In this application, we seek to examine the mechanisms whereby the HIV-1 Tat protein modulates sod2 expression thereby contributing to a state of oxidative stress. We have defined a Tat-sensitive Sp-responsive element (TSS) containing multiple binding sites for the oxidant sensitive Sp family of transcription factors in the regions of the sod2 promoter proximal (up to nucleotide -210) to the transcriptional start and have shown that Tat decreases the Sp1/Sp3 ratio on the TSS. Given that Sp3 has reduced transcriptional activity compared to Sp1 and an inhibitory domain that that represses transcription, this shift in occupancy of the promoter will result in alteration of sod2 transcription. Our hypothesis is that HIV-1 Tat dysregulates sod2 expression via modulation of Sp1 and Sp3 transcription factors and contributes to a state of oxidative stress during HIV infection. In order to address the hypothesis we have crafted a research plan that combines in vivo mouse models to examine the oxidative state in the lungs during HIV infection and in vitro mechanistic experiments to probe potential molecular mechanisms for how Tat alters the Sp1/Sp3 ratio on the sod2 promoter. Lastly we will leverage our current bank of bronchalveolar lavage (BAL) and blood biospecimens from HIV+ individuals with and without PAH to address whether in HIV-infected patients, to investigate oxidative stress in human biological specimens of HIV-PAH and to ask mechanistic questions regarding the modulation of sod2 in HIV infection.

 描述（由申请人提供）：自从引入高效抗逆转录病毒联合疗法（HAART）以来，HIV 感染的发病机制现在更常见的是一种慢性、长期感染，这极大地改变了这种疾病的流行病学。低水平的病毒复制暴露了对许多心脏和肺部疾病的易感性，这些疾病现在是发病和死亡的更常见原因，例如与艾滋病毒相关的肺动脉高压。 (HIV-PAH) PAH 在 HIV 感染者中的患病率大约是普通人群的 25 倍。我们发现 HIV Tat 蛋白可促进许多与其功能不直接相关的促氧化和促炎症反应。例如，我们和其他人已经证明，Tat 通过消耗谷胱甘肽和改变内皮细胞中的锰依赖性超氧化物歧化酶 (MnSOD) 来诱导氧化应激。细胞中氧化剂的增加可以促进许多生理反应，例如炎症、细胞凋亡和随后的抗凋亡细胞增殖，从而导致肺血管闭塞，因此，我们认为 Tat 诱导的氧化应激具有中枢作用。在启动最终导致 HIV-PAH 肺血管重塑的致病级联中的作用在本申请中，我们试图研究 HIV-1 Tat 蛋白调节 sod2 表达从而导致一种状态的机制。我们定义了一个 Tat 敏感 Sp 响应元件 (TSS)，其在 sod2 启动子邻近转录起始点的区域（直至核苷酸 -210）中包含氧化敏感 Sp 转录因子家族的多个结合位点。已经表明，Tat 降低了 TSS 上的 Sp1/Sp3 比率，鉴于与 Sp1 相比，Sp3 的转录活性降低，并且具有抑制转录的抑制结构域，因此这种转变。我们的假设是，HIV-1 Tat 通过调节 Sp1 和 Sp3 转录因子来调节 sod2 的表达，并导致 HIV 感染期间的氧化应激状态。制定了一项研究计划，结合体内小鼠模型来检查 HIV 感染期间肺部的氧化状态，并通过体外机制实验来探索 Tat 如何改变最后，我们将利用我们现有的支气管肺泡灌洗液 (BAL) 库和来自患有和不患有 PAH 的 HIV+ 个体的血液生物样本来研究 HIV 感染患者中是否存在氧化应激。 HIV-PAH 并询问有关 HIV 感染中 sod2 调节的机制问题。