Impact of HIV Infection on Myocardial Cell Homeostasis

HIV 感染对心肌细胞稳态的影响

• 批准号: 9924915
• 负责人: Manish Kumar Gupta
• 金额: $ 51.51万
• 依托单位: UNIVERSITY OF CENTRAL FLORIDA
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-01 至 2022-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9924915
• 关键词: Acquired Immunodeficiency Syndrome; Address; Affect; Animal Model; Apoptosis; Apoptotic; Attenuated; Autophagocytosis; Autophagosome; Biochemical; Bioenergetics; Biological; Calcium; Cardiac; Cardiac Myocytes; Cardiomyopathies; Cardiotoxicity; Cell Death; Cell Survival; Cell physiology; Cells; Chronic Disease; Clinical; Comorbidity; Complication; Conditioned Culture Media; Data; Depressed mood; Electron Transport; Elements; Event; Excision; Fibrosis; GRP78 gene; Generations; Genes; Genetic; HIV; HIV Infections; HIV-1; Heart failure; Homeostasis; Human; In Vitro; Infection; Intelligence; Knock-out; Lysosomes; Macaca; Mediating; Membrane Potentials; Mitochondria; Molecular; Myocardial; Necrosis; Neonatal; Nicotinamide adenine dinucleotide; Outcome; Outcome Study; Pathogenicity; Pathology; Pathway interactions; Patients; Peripheral Blood Mononuclear Cell; Population; Proteins; Quality Control; Rattus; Reactive Oxygen Species; Respiration; Role; SIV; Sampling; Serum; T-Lymphocyte; Testing; Tissues; Toxic effect; Up-Regulation; Validation; Ventricular; Viral; Viral Proteins; antiretroviral therapy; base; clinically relevant; design; endoplasmic reticulum stress; genetic regulatory protein; heart function; human tissue; in vivo; inhibition of autophagy; macrophage; misfolded protein; mitochondrial dysfunction; mitochondrial membrane; mortality; mouse model; mutant; nef Protein; novel therapeutics; operation; preclinical study; prevent; response; stem; treatment strategy

SUMMARY Antiretroviral therapy (ART) has significantly reduced HIV-1/AIDS-related mortality and transformed HIV infection into a chronic disease. Cardiomyopathy remains one of the leading causes of co-morbidity and heart failure in HIV-1/AIDS. However, the underlying mechanism(s) of HIV-induced cardiotoxicity and heart failure remain largely unknown. Due to a lack of HIV productive infection in cardiomyocytes, it is believed that indirect pathways involving viral and cellular factors with toxic effects are involved in HIV-induced cardiomyopathy. Among viral proteins, Nef, which is released by infected cells such as macrophages and T-cells and is taken up by neighboring cells, is a possible HIV-1 toxic factor. Nef possesses several interesting capacities that compromise multiple cellular processes including autophagy, apoptosis and viability. Our preliminary data demonstrate that Nef protein accumulates in the cardiomyocytes of HIV-infected patients and SIV-infected macaques even on ART, thus demonstrating the clinical relevance of studying Nef expression in cardiomyocytes. Accordingly, our preliminary data show that exposure of cardiomyocytes to Nef causes dysregulation of autophagy and triggers apoptosis. Mechanistically, our data indicate that Nef inhibits the terminal step of autophagy through inhibition of Beclin 1 and Rab7 localization and function. Further, we found that Nef dysregulates mitochondrial turnover, generation of ROS and decreases mitochondrial membrane potential. This leads to compromised mitochondrial function causing aberrations in cellular bioenergetic pathways. Additionally, we found that Nef reduces cellular NAD+ level, an important metabolite for cellular function and regulates cellular autophagy. Based on these observations, we hypothesize that HIV-1 Nef protein perturbs protein quality control (PQC) in cardiomyocytes by dysregulating autophagy and causes gradual cell death and consequently cardiomyopathy by impacting several critical elements that control cell homeostasis. Accordingly, our most recent results suggest that Nef induces ER-stress, as evidenced by upregulation of several of its key regulators including GRP78. Additionally we found that ART treatment causes mitochondrial abnormalities. In this application, we will examine our hypothesis by determining the role Nef and ART in cardiac PQC and cellular function in primary cardiomyocytes (Aim 1). We will investigate the molecular pathways of Nef-induced dysregulation of autophagy including the physical and functional interplay between Nef and Beclin 1, Rab7 and several other regulatory proteins involved in PQC (Aim 2). We will assess if stimulation of autophagy through NAD+ might offer a new pathway for suppressing Nef-induced pathology in cardiomyocytes (Aim 3). To address these questions, we will perform our studies in vitro using primary cardiomyocytes, validate in animal models and confirm in HIV+ clinical samples with ART. The outcome of these studies will unravel the molecular mechanism involved in HIV-induced cardiomyopathy and will help to develop intelligent strategies to prevent HIV-1 associated cardiomyopathy.

概括 抗逆转录病毒疗法（ART）显着降低了HIV-1/AIDS相关死亡率并转化为HIV 感染慢性疾病。心肌病仍然是合并症和心脏的主要原因之一 HIV-1/AIDS失败。但是，HIV诱导的心脏毒性和心力衰竭的基本机制 在很大程度上未知。由于心肌细胞缺乏HIV生产感染，因此认为间接 HIV诱导的心肌病涉及涉及病毒和细胞因子的病毒和细胞因子的途径。 在病毒蛋白中，NEF被感染的细胞（例如巨噬细胞和T细胞）释放，被采用 通过相邻细胞，可能是HIV-1毒性因子。 NEF具有几个有趣的能力 损害多个细胞过程，包括自噬，凋亡和生存能力。我们的初步数据 证明NEF蛋白在HIV感染患者的心肌细胞中积累并感染了SIV 即使是在艺术方面的猕猴，也证明了研究NEF表达在 心肌细胞。因此，我们的初步数据表明，心肌细胞暴露于NEF原因 自噬和触发凋亡的失调。从机械上讲，我们的数据表明NEF抑制了 通过抑制Beclin 1和RAB7定位和功能，自噬的末端步骤。此外，我们发现 NEF失调线粒体更新，ROS产生并降低线粒体膜 潜在的。这导致线粒体功能受损，导致细胞生物能的畸变 途径。此外，我们发现NEF降低了细胞NAD+水平，这是一个重要的细胞代谢物 功能并调节细胞自噬。基于这些观察结果，我们假设HIV-1 NEF蛋白 通过失调自噬并导致逐渐细胞的心肌细胞中的Perturbs蛋白质质量控​​制（PQC） 通过影响控制细胞稳态的几个关键元素，死亡和心肌病。 因此，我们最近的结果表明，NEF引起了ER应力，这可以从上调上调 它的几个关键监管机构在内，包括GRP78。另外，我们发现艺术治疗会导致线粒体 异常。在此应用中，我们将通过确定NEF和艺术在 一级心肌细胞中的心脏PQC和细胞功能（AIM 1）。我们将研究分子 NEF诱导的自噬失调的途径，包括物理和功能相互作用 NEF和Beclin 1，Rab7和其他几种参与PQC的调节蛋白（AIM 2）。我们将评估是否 通过NAD+刺激自噬可能为抑制NEF诱导的病理学提供新的途径 心肌细胞（AIM 3）。为了解决这些问题，我们将在体外使用主要的研究进行研究 心肌细胞，在动物模型中验证，并在HIV+ ART临床样品中确认。结果 这些研究将揭示与HIV诱导的心肌病有关的分子机制，并将有助于 制定明智的策略，以防止HIV-1相关的心肌病。