Mechanisms of Heart Failure in HIV/AIDS: Nucleotides and NRTIs

HIV/艾滋病导致心力衰竭的机制：核苷酸和 NRTI

• 批准号: 8915899
• 负责人: WILLIAM LEWIS
• 金额: $ 63.77万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-08 至 2015-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8915899
• 关键词: AIDS/HIV problem; Address; Adverse effects; Affect; Anti-Retroviral Agents; Antioxidants; Area; Attenuated; Biological; Biological Assay; Biological Factors; Cardiac; Cardiomyopathies; Cells; Chemicals; Congestive Heart Failure; Cytoplasm; Cytoplasmic Protein; DNA; DNA biosynthesis; Development; Dose; Equilibrium; Event; Exhibits; Functional disorder; Gene Transfer Techniques; Genetically Engineered Mouse; HIV; HIV-1; Health; Heart; Heart failure; In Vitro; Infection; Intake; Knockout Mice; Libraries; Manganese; Metabolism; Mitochondria; Mitochondrial DNA; Mitochondrial Proteins; Mus; Muscle Cells; Mutation; Myocardial; Myocardium; Nucleosides; Nucleotide Biosynthesis; Nucleotides; Organ; Oxidants; Oxidative Stress; Pathogenesis; Patients; Perfusion; Phenotype; Phosphorylation; Physiological; Porphyrins; Prevalence; Proteins; Pump; Purines; Pyrimidine; Resources; Resveratrol; Reverse Transcriptase Inhibitors; Ribonucleotide Reductase; Ribonucleotide Reductase Inhibitor; Role; SAM Domain; SOD2 gene; Sarcoplasm; Supplementation; Syndrome; Therapeutic; Therapeutic Agents; Toxic effect; Transgenic Mice; Transgenic Organisms; Work; base; catalase; catalyst; clinically relevant; heart cell; improved; in vivo; overexpression; prevent; purine; replicase; research study; tool; tripolyphosphate

DESCRIPTION (provided by applicant): This project defines how metabolism of nucleoside reverse transcriptase inhibitors (NRTIs) for HIV/AIDS causes defective mitochondrial (mt-) DNA replication, oxidative stress and cardiomyopathy (CM, a weakness of the heart muscle with poor pump function). Along with the benefit of increased survival in HIV/AIDS, combinations that include NRTIs carry devastating mitochondrial side effects, including CM. Mitochondrial (mt-) DNA depletion and mutation, and oxidative stress are key mechanisms in CM and CHF, and for development of NRTI toxic mitochondrial side effects based of defective mtDNA replication. The working hypothesis states: In myocardial cells, NRTIs interact with proteins that control the nucleotide biosynthesis and salvage for mtDNA replication. Ribonucleotide reductase (RNR) and SAM domain and HD domain-containing protein 1 (SAMHD1) alter abundance of dNTPs for mtDNA replication. RNR inhibition or increased activity of SAMHD1 depletes native dNTP pools, increases abundance of NRTI-TPs (or both). mtDNA depletion and mutation, oxidative stress, and CM are the phenotypic signature. Through clinically relevant experiments using genetically engineered mice, the project will dissect nucleotide pool imbalance in the sarcoplasm and mitochondria of CM myocytes in HIV/AIDS. Oxidative stress and CM are ameliorated by protecting cardiac mitochondria with manganese porphyrin catalytic antioxidants that localize to mitochondria. AIM 1: To define the role of RNR activity and inhibition in modulating cardiac cytoplasmic and mitochondrial nucleotide pools in the CM of HIV/AIDS. Transgenic mice (TGs) that overexpress RNR are in the lab presently. In heart cells, RNR overexpression (by transgenesis) or its inhibition (e.g., exogenous resveratrol) alters nucleotide pools for phosphorylation and incorporation into mtDNA. Nucleotide pools are defined with dNTP assays and correlated with cardiac physiological, pathological and pharmacological studies. AIM 2: To define the role of SAMHD1 activity (and absence) in modulating the myocardial cytoplasmic and mitochondrial nucleotide pools in the CM of HIV/AIDS. SAMHD1 null mice are powerful biological tools to increase the pool of dNTPs in heart cells. Conversely, cardiac targeted transgenic overexpression of SAMHD1 increases dN pools. NRTI treatment generates NRTI-TPs that inhibit pol ? and create CM. Cardiac nucleotide pools are determined with dNTP assays and correlative physiological, pathological and pharmacological parameters. AIM 3: To prevent and treat CM in HIV/AIDS with "replacement" by ameliorating mitochondrial oxidative stress. "Replacement of function" is accomplished using TGs from AIM 1 and 2 that are co- administered manganese porphyrin catalytic antioxidants (to provide SOD2- and catalase-like activity that bolsters antioxidant defense) and prevent or attenuate RNR- or SAMHD1-induced cardiac changes and attenuate CM pathophysiological changes.

描述（由申请人提供）：该项目定义了用于治疗艾滋病毒/艾滋病的核苷逆转录酶抑制剂（NRTI）的代谢如何导致线粒体（mt-）DNA复制缺陷、氧化应激和心肌病（CM，泵血不良的心肌无力）功能）。除了提高 HIV/AIDS 患者的生存率之外，包含 NRTI 的组合还具有毁灭性的线粒体副作用，包括 CM。线粒体 (mt-) DNA 耗竭和突变以及氧化应激是 CM 和 CHF 的关键机制，也是基于 mtDNA 复制缺陷而产生 NRTI 有毒线粒体副作用的关键机制。工作假设指出：在心肌细胞中，NRTI 与控制核苷酸生物合成和线粒体 DNA 复制抢救的蛋白质相互作用。核糖核苷酸还原酶 (RNR) 和 SAM 结构域以及含有 HD 结构域的蛋白 1 (SAMHD1) 会改变 mtDNA 复制的 dNTP 丰度。 RNR 抑制或 SAMHD1 活性增加会耗尽天然 dNTP 池，增加 NRTI-TP 丰度（或两者兼而有之）。 mtDNA 耗竭和突变、氧化应激和 CM 是表型特征。通过使用基因工程小鼠进行临床相关实验，该项目将剖析 HIV/AIDS 中 CM 肌细胞的肌浆和线粒体的核苷酸库失衡。通过使用位于线粒体的锰卟啉催化抗氧化剂保护心脏线粒体，可以改善氧化应激和心肌梗死。目标 1：确定 RNR 活性和抑制在调节 HIV/AIDS CM 中的心肌细胞质和线粒体核苷酸池中的作用。过度表达 RNR 的转基因小鼠 (TG) 目前已在实验室中。在心脏细胞中，RNR 过度表达（通过转基因）或其抑制（例如外源白藜芦醇）会改变磷酸化和掺入 mtDNA 的核苷酸库。核苷酸池通过 dNTP 测定确定，并与心脏生理、病理和药理学研究相关。目标 2：确定 SAMHD1 活性（和缺失）在调节 HIV/AIDS CM 中心肌细胞质和线粒体核苷酸库中的作用。 SAMHD1 缺失小鼠是增加心脏细胞中 dNTP 库的强大生物工具。相反，心脏靶向转基因 SAMHD1 过度表达会增加 dN 池。 NRTI 处理产生抑制 pol ? 的 NRTI-TP。并创建CM。心脏核苷酸池通过 dNTP 测定和相关生理、病理和药理学参数来确定。目标3：通过改善线粒体氧化应激来“替代”预防和治疗HIV/AIDS中的CM。 “功能替代”是使用来自 AIM 1 和 2 的 TG 来完成的，这些 TG 是共同施用的锰卟啉催化抗氧化剂（以提供 SOD2 和过氧化氢酶样活性，增强抗氧化防御），并预防或减弱 RNR 或 SAMHD1 诱导的心脏变化并减弱 CM 病理生理变化。