Cardioprotective Efficacy ofMg-Supplementation during HAART Therapy

描述(由申请人提供)：替诺福韦(TFV)、依法韦仑(EFV)和利托那韦(RTV)是用于大多数艾滋病毒患者治疗的一线高效抗逆转录病毒疗法(HAART)药物。它们的使用被很好地证明与增加心血管功能障碍和共病毒性有关，但补充镁的潜在益处尚未被调查。几种蛋白水解酶抑制剂(PI)，特别是RTV和EFV可导致内皮细胞内活性氧生成增加和细胞功能障碍。与PI使用相关的血脂异常也可能是心肌梗死风险增加的原因。大多数NRTI，包括TVF，都表现出不同程度的线粒体毒性。我们利用培养的内皮细胞进行的体外研究表明，细胞外高镁可减弱AZT诱导的ROS形成增加，减少PGI2和NO的释放，并降低细胞存活率。RTV诱导的细胞毒性也观察到了类似的效应。AZT对大鼠模型的治疗引起全身氧化应激、中性粒细胞激活和心脏组织炎性白细胞的渗透；最有趣的是，补充镁能抑制所有这些氧化指标。根据已报道的结果和我们自己的观察，我们假设：(I)大多数HAART的促氧化特性可能直接或间接导致内皮损伤和相关的代谢紊乱，从而导致心功能障碍；(Ii)补充镁具有全身和心脏保护作用，因为它对HAART诱导的氧化毒性具有调节作用。其具体目的是：1)建立剂量和时间依赖的全身性氧化应激以及TFV、EFV或RTV治疗引起的心脏功能障碍的发病机制和进展。2)确定膳食补镁是否通过抗氧化机制减轻HAART诱导的各种全身病变和心功能不全。3)确定HAART对培养内皮细胞的细胞毒作用机制，评价铁和炎性细胞因子的作用，以及高水平镁的保护作用。氧化应激将由脂质过氧化产物(8-异前列腺素、过氧化脂质)、血液和组织谷胱甘肽状态以及NO释放来确定。将评估HAART诱导的代谢效应(葡萄糖耐受、血脂紊乱)，并将使用免疫组织化学和病理学技术定位炎症标记物和白细胞渗透。ICAM和eNOS表达的改变将通过蛋白质印迹分析来评估。心功能的改变将通过超声心动图进行原位检测。这项拟议的探索性研究可能揭示补充镁作为一种有效而廉价的辅助治疗的潜在用处，以将HAART相关的心血管氧化和代谢副作用的有害影响降至最低。 公共卫生相关性：对HIV-1患者使用高效抗逆转录病毒疗法(HAART)药物可能会导致不良的心血管副作用。这项拟议的项目将有助于确定目前推荐的三种HAART药物(替诺福韦、依法韦仑和利托那韦)引起的细胞毒性和心功能损害，以及补充镁的潜在益处。

DESCRIPTION (provided by applicant): Tenofovir (TFV), efavirenz (EFV) and ritonavir (RTV) are the first line highly active antiretroviral therapy (HAART) agents used in most treatment of HIV patients. Their uses are well documented to be associated with increased cardiovascular dysfunction and co-morbid toxicity, but the potential beneficial effect of Mg- supplementation has not been investigated. Several protease inhibitors (PI), RTV in particular, and EFV can cause elevated endothelial cell reactive oxygen species generation and cellular dysfunction. Dyslipidemia associated with PI use may also account for increased risk of myocardial infarction. Most NRTIs, TVF included, display varying degrees of mitochondrial toxicity. Our in vitro studies using cultured endothelial cells indicate that high extracellular Mg attenuated AZT-induced increases in ROS formation, decreased release of PGI2 and NO and reduced cell viability. Similar effects were observed for RTV-induced cytotoxicity. AZT treatment in a rat model provoked systemic oxidative stress, neutrophil activation and inflammatory WBC infiltration of cardiac tissue; most intriguingly, all these oxidative indices were suppressed by dietary Mg supplementation. Based on the reported findings and our own observations, we postulate that: (i) prooxidant properties of most HAARTs may directly or indirectly cause endothelial injury and related metabolic disturbance leading to cardiac dysfunction; and (ii) Mg-supplementation provides systemic and cardioprotective benefits due to its modulating role against HAART-induced oxidative toxicity. The specific aims are: 1) Establish the dose- and time- dependent systemic oxidative stress and cardiac pathogenesis and progression of dysfunction resulting from TFV, EFV, or RTV treatment in rats. 2) Determine if dietary Mg-supplementation attenuates each HAART- induced systemic pathogenesis and cardiac dysfunction through an anti-oxidative mechanism. 3) Determine the cytotoxic mechanisms of each HAART treatment in cultured endothelial cell (EC); assess the contribution of iron and inflammatory cytokines, and the protection afforded by high levels of Mg. Oxidative stress will be determined biochemically by lipid peroxidation products (8-isoprostane, lipid hydroperoxides), blood and tissue glutathione status and NO release. HAART-induced metabolic effects will be assessed (glucose intolerance, plasma lipid disturbances), and immunohistochemical and pathology techniques will be used to localize inflammatory markers and WBC infiltration. Alteration in iCAM and eNOS expression will be assessed by western blot analysis. Changes in cardiac function will be determined in situ by echocardiogram. This proposed exploratory study may reveal a potential usefulness of Mg-supplement as an effective, yet inexpensive adjunct therapy to minimize the deleterious impact of HAART-related cardiovascular oxidative and metabolic side effects. PUBLIC HEALTH RELEVANCE: The use of highly active antiretroviral therapy (HAART) agents for HIV-1 patients may cause adverse cardiovascular side effects. The proposed project will help to determine the cytotoxicity and cardiac functional impairment caused by three currently recommended HAART agents (tenofovir, efavirenz and ritonavir), and the potential beneficial effects of Mg-supplementation.