Mechanism of Fetal and Neonatal Handling of HIV Drugs

描述（由申请人提供）：尽管大量感染艾滋病毒的孕妇和新生儿接受抗逆转录病毒药物的长期治疗，但对这些药物在子宫内和新生儿肾脏中的处理知之甚少。虽然这些药物通常被认为在短期内对胎儿和新生儿是相对安全的，但对未被发现的毒性和长期影响的担忧是合理的。这是儿童药理学中一个更普遍关注的问题的一部分，即由于对药物处理能力成熟的机制了解不足，导致剂量不当导致不必要的早产儿和新生儿药物毒性。关于用于治疗HIV的药物，来自PI小组和其他人的体外数据表明，有机阴离子转运蛋白（Oat1和/或Oat3）是调节抗逆转录病毒处理的关键基因。PI的小组是第一个识别出Oat1以及一些相关基因的，并且最近发表了第一个成年Oat1和Oat3敲除小鼠的数据，这些数据证明了有机阴离子（OA）运输缺陷和药物处理改变。然而，某些OA化合物和药物在成年小鼠体内的数据显示，与主要从非洲爪蟾卵母细胞运输试验中获得的体外数据存在差异。此外，我们最近的发育研究，使用一种新的离体方法来分析OA处理，表明OA运输的不依赖于燕麦的机制可能在子宫和新生儿中很重要。根据大量的初步数据，在这篇修订后的申请中，我们假设早产儿和新生儿体内OA药物转运的机制与成人不同。此外，我们假设，虽然Oat1和Oat3是成人和新生儿环境中的关键抗逆转录病毒转运蛋白，但在子宫内，其他新的转运蛋白也有助于处理用于治疗HIV的抗逆转录病毒药物。这些途径需要被定义。因此，我们的目标是解决以下问题：1)在新生儿野生型和敲除动物肾脏中，Oat1和Oat3在抗逆转录病毒药物净转运中的体内作用是什么？2)子宫内抗逆转录病毒转运的其他途径是否活跃？结合遗传、体内生理、微阵列和表达克隆方法来解决这些问题，利用PI的团队在OAT生物学和肾脏发育方面的联合优势。该结果应该为（可能不同的）子宫内和新生儿环境中的药物处理机制提供关键见解，并为转化研究奠定基础。我们已经解决了先前申请的所有批评，包括翻译问题（请参阅合作者的来信），并提供了新的初步数据。

DESCRIPTION (provided by applicant): Despite the large number of pregnant women and neonates infected with HIV receiving long-term treatment with antiretroviral agents, little is understood about the handling of these drugs in utero and in the neonatal kidney. Although the drugs are generally considered to be relatively safe for the fetus and neonate over the short-term, there is justifiable concern over undetected toxicities and long-term effects. This is part of a more general concern in pediatric pharmacology that unnecessary preterm and neonatal drug toxicity results from inappropriate dosing due to poorly understood mechanisms of maturation of drug handling capacity. With respect to drugs used for the treatment of HIV, in vitro data from the PI's group and others indicates that organic anion transporters (Oats), Oat1 and/or Oat3, are the key genes regulating antiretroviral handling. The PI's group was the first to identify Oat1, as well as a number of related genes, and has recently published the first adult Oat1 and Oat3 knockout mice data, which demonstrate defective organic anion (OA) transport and altered drug handling. However, the in vivo data in adult mice for certain OA compounds and drugs has revealed differences with in vitro data obtained mainly from Xenopus oocyte transport assays. Moreover, our recent developmental studies, using a novel ex-vivo method to analyze OA handling, suggest that Oat- independent mechanisms of OA transport may be important in utero and in neonates. Drawing on considerable preliminary data, in this REVISED application, we hypothesize that the mechanisms of in vivo OA drug transport are different in preterm and neonatal compared to adults. Furthermore, we hypothesize that, while Oat1 and Oat3 are the key antiretroviral transporters in adults and probably in the neonatal setting, in utero additional novel transporters also contribute to the handling of antiretrovirals used to treat HIV. These pathways need to be defined. We therefore aim to address the following questions: 1) What are the in vivo roles of Oat1 and Oat3 in net transport of antiretrovirals in the kidneys of neonatal wildtype and knockout animals? 2) Are additional pathways for transport of antiretrovirals active in utero? A combination of genetic, in vivo physiological, microarray and expression cloning methods will be employed to approach these questions, leveraging the joint strengths of the PI's group in OAT biology and kidney development. The results should provide key insights into the (likely different) mechanisms of drug handling in the in utero as well as neonatal settings and set the stage for translational studies. We have addressed all the criticisms of the prior application, including translational issues (please see letters from collaborators) and also provide new preliminary data.