Global HIV Drug Therapies and Mitochondrial Complications and Mechanisms

描述(由申请人提供)：线粒体(MT)功能障碍引起的脂肪萎缩和其他毒性是核苷逆转录酶抑制剂(NRTI)常见的并发症。由于高甘油三酯血症和胰岛素抵抗也经常与脂肪萎缩相关；使用d4T或ZDV也可能增加接受这些药物治疗的患者的心血管风险。尽管它们有毒性，但这些NRTI是发展中国家使用的抗逆转录病毒(ARV)方案的广泛使用的组成部分。即使在美国，ZDV和拉米夫定(3TC)仍然被卫生和公众服务部列为首选的ARV初始方案之一。因此，了解这些MT毒性发生的致病机制对于找到适当的方法来监测和预防或最大限度地减少这些药物的并发症是重要的。夏威夷大学与泰国红十字会艾滋病研究中心合作，打算在泰国曼谷开展一项为期72周的前瞻性随机临床试验，评估在150名HIV感染者中短期服用ZDV(24周)后使用ZDV(n=50)与持续使用ZDV+3TC(n=50)或替诺福韦(TDF)+恩曲他滨(n=50)(n=50)的相对毒性。这项临床试验将主要由泰国公共卫生部提供资金，因为这项试验对泰国的国家抗逆转录病毒治疗政策很重要。 我们推测，这些药物的MT毒性主要是由线粒体氧化磷酸化(OXPHOS)蛋白/酶活性水平的变化驱动的，而线粒体氧化磷酸化(OXPHOS)蛋白/酶的活性水平反过来又增加了线粒体活性氧应激和脂肪细胞及前脂肪细胞的凋亡，并且这些力量严重依赖于这些药物的细胞内浓度。我们进一步假设，脂肪、外周血单核细胞(PBMC)或颊拭子(颊拭子)中OXPHOS蛋白/酶活性的水平将与双能X射线吸收法(DEXA)评估的肢体脂肪含量的减少相关。如果这些假设得到验证，那么在理解HIV脂肪减少的机制方面将会对人类健康产生重大的影响。此外，PBMCs或口腔细胞的OXPHOS蛋白/酶活性可作为先发制人的工具，监测受试者线粒体诱导的肢体脂肪丢失的风险。 我们打算使用一种新的免疫学方法和免疫组织化学、mtDNA拷贝/细胞、线粒体特异性氧化损伤(8-oxo-deoxguanine)和细胞凋亡来评估基线、wk 24和wk 72的脂肪组织、PBMCs和口腔细胞的线粒体OXPHOS蛋白/酶活性。此外，还将评估PBMCs细胞内ZDV、d4T、3TC、FTC和TDF三磷酸盐的浓度与线粒体毒性的暴露反应关系。

DESCRIPTION (provided by applicant): Lipoatrophy and other toxicities due to mitochondrial (mt) dysfunction are common complications seen with the nucleoside reverse transcriptase inhibitors (NRTIs). As hypertriglyceridemia and insulin resistance are also frequently observed in association with lipoatrophy; the use of d4T or ZDV may also increase cardiovascular risk in patients treated with these medications. Despite their toxicities, these NRTIs are widely used components of antiretroviral (ARV) regimens used in developing countries. Even in the United States, ZDV together with lamivudine (3TC) continue to be listed as one of the preferred initial ARV regimens by the Department of Health and Human Services. Therefore, understanding the pathogenic mechanisms underlying the development of these mt toxicities are important to finding appropriate ways to monitor and prevent or minimize the complications of these medications. The University of Hawaii in collaboration with the Thai Red Cross AIDS Research Centre intends to launch a longitudinal 72 week prospective, randomized clinical trial in Bangkok, Thailand assessing the relative toxicities of short-term d4T (24 week) use followed by ZDV (n=50) compared to continuous ZDV + 3TC (n=50) or tenofovir (TDF) + emtricitabine (FTC) (n=50), all given with nevirapine (NVP) in 150 HIV+ na¿ve patients. The clinical trial will be predominantly funded by the Thai Ministry of Public Health as this trial is important to its national ARV treatment policies. We hypothesize that the mt toxicities of these medications are driven primarily by alterations in mitochondrial oxidative phosphorylation (OXPHOS) protein/enzyme activity levels, which in turn increase mitochondrial reactive oxygen stress and adipocytes and pre-adipocyte apoptosis, and that these forces are heavily dependent on the intracellular concentration of these drugs. We further hypothesize that levels of OXPHOS proteins/enzyme activities in fat, peripheral blood mononuclear cells (PBMCs) or buccal cells (cheek swabs) will correlate with a decrease in limb fat content as assessed by dual energy x-ray absorptiometry (DEXA). Should these hypotheses be verified, there would be significant human health relevance in the understanding of the pathogenesis of HIV fat loss. Additionally, PBMCs' or buccal cells' OXPHOS protein/enzyme activities may serve as tools to monitor subjects preemptively for the risk of mitochondrial induced limb fat loss. We intend to evaluate adipose tissue, PBMCs, and buccal cells at baseline, wk 24, and wk 72 for mitochondrial OXPHOS protein/enzyme activity using a novel immunological assay and by immunohistochemistry, mtDNA copies/ cells, mitochondrial specific oxidative damage (8-oxo-deoxyguanine), and apoptosis. Additionally, PBMCs intracellular concentrations of ZDV, d4T, 3TC, FTC, and TDF triphosphates will be assessed for exposure-response relationships with mitochondrial toxicity.