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 相关死亡率并转化了 HIV 感染转为慢性疾病。心肌病仍然是合并症和心脏病的主要原因之一 HIV-1/艾滋病失败。然而，HIV 引起的心脏毒性和心力衰竭的潜在机制 仍然很大程度上不为人所知。由于心肌细胞中缺乏 HIV 产生性感染，人们认为间接 HIV 引起的心肌病涉及具有毒性作用的病毒和细胞因子的途径。 在病毒蛋白中，Nef 由巨噬细胞和 T 细胞等受感染细胞释放，并被摄入 邻近细胞的作用，是一种可能的 HIV-1 毒性因子。 Nef 拥有一些有趣的能力 损害多种细胞过程，包括自噬、细胞凋亡和活力。我们的初步数据 证明 Nef 蛋白在 HIV 感染者和 SIV 感染者的心肌细胞中积累 猕猴甚至在 ART 上也得到了证实，从而证明了研究 Nef 表达的临床意义 心肌细胞。因此，我们的初步数据表明，心肌细胞暴露于 Nef 会导致 自噬失调并引发细胞凋亡。从机制上讲，我们的数据表明 Nef 抑制 通过抑制 Beclin 1 和 Rab7 定位和功能实现自噬的最终步骤。进一步，我们发现 Nef 失调线粒体周转、ROS 的产生并减少线粒体膜 潜在的。这导致线粒体功能受损，导致细胞生物能失常 途径。此外，我们发现 Nef 降低了细胞 NAD+ 水平，NAD+ 是细胞的重要代谢物。 发挥作用并调节细胞自噬。基于这些观察，我们假设 HIV-1 Nef 蛋白 通过自噬失调扰乱心肌细胞中的蛋白质质量控​​制 (PQC)，并导致细胞逐渐 通过影响控制细胞稳态的几个关键因素来导致死亡并导致心肌病。 因此，我们最近的结果表明 Nef 会诱导 ER 应激，这一点可以通过上调 其几个关键监管机构包括 GRP78。此外，我们发现 ART 治疗会导致线粒体 异常。在此应用中，我们将通过确定 Nef 和 A​​RT 在 心脏 PQC 和原代心肌细胞的细胞功能（目标 1）。我们将研究分子 Nef 诱导的自噬失调的途径，包括自噬之间的物理和功能相互作用 Nef 和 Beclin 1、Rab7 以及其他几种参与 PQC 的调节蛋白（目标 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途径 心肌细胞（目标 3）。为了解决这些问题，我们将使用初级进行体外研究 心肌细胞，在动物模型中进行验证，并通过 ART 在 HIV+ 临床样本中进行确认。结果 这些研究将揭示艾滋病毒引起的心肌病的分子机制，并将有助于 制定预防 HIV-1 相关心肌病的智能策略。