The Role in OAT1 in Uremia

尿毒症中的 OAT1 项目概要/摘要 我们 (NKT) 发现的有机阴离子转运蛋白 1 (OAT1/SLC22A6) 是典型的肾脏有机阴离子 (PAH) 转运蛋白负责转运许多药物（例如利尿剂、抗病毒药物、非甾体抗炎药）。基于 我们在上一个项目期间对 Oat1 敲除小鼠进行的体内研究以及我们和 其他，OAT1 现在被认为是近端小管感应和消除的核心组成部分 肠道微生物产物和尿毒症毒素的机制。此外，我们实验室的啮齿动物最新数据如下： 以及其他人的人体研究表明，OAT1 依赖性功能对于残余肾功能至关重要 慢性肾病。然而，我们的代谢组学和转录组学研究真正引人注目的是 OAT1 几乎只在肾脏中表达，可调节肠道以外的全身代谢 微生物产品和尿毒症毒素。例如，它调节许多信号脂质、柠檬酸循环 中间体、胆汁酸和维生素/辅因子。事实上，OAT1 可能是影响最广泛的肾脏基因。 对全身代谢的影响。尽管 CKD 是一种多因素疾病，但其中一个因素是 作为近端小管的 OAT1 依赖性感知和消除逐渐丧失的代谢后果 功能下降。因此，我们假设，在 CKD 中，OAT1 介导的蛋白结合蛋白的正常功能 近端小管中的代谢传感和信号传导受到严重破坏，导致 小分子代谢和信号传导。这是因为 OAT1 作为中枢的内源性作用 涉及肠道微生物衍生代谢物的更大代谢网络的组成部分，其中一些参与 严重肾脏疾病的尿毒症毒性，但也会影响色氨酸和脂质代谢以及 其他代谢过程。使用最新的方法来集成大型组学数据集和 特别新颖的多尺度代谢重建方法（将 Recon3D 与基因组尺度相结合） 微生物组重建），我们将在以下条件下定义 Oat1 KO 小鼠的途径：a）肠道 微生物组存在或已耗尽； b) 肾功能受损。最终我们将完全拥有 分析了 Oat1 KO 与 WT、健康与耗尽的肠道微生物组以及假手术与 5/6 的组合 肾切除术，在血清、肾脏、肝脏和粪便中取样。这将解决（在小鼠中）相对重要性 每个改变的状态对尿毒症毒素水平、生化途径和整体多尺度代谢的影响 通过对每种情况进行基因组规模的代谢重建来确定影响。的一部分 组学数据已经获得（KO效应、部分肠道微生物效应）。因此，该项目将产生一个 验证了正常生理和疾病状态下以 OAT1 为中心的代谢的详细图谱，可能是 对于任何多特异性“药物”转运蛋白来说，这都是首创（Nigam，Nature Reviews Drug Discovery，2015）。的 研究可能会导致设计通过影响 OAT1 来改善 CKD 代谢异常的策略 函数或表达式。

OAT1 IN UREMIA PROJECT SUMMARY/ABSTRACT Organic anion transporter 1 (OAT1/SLC22A6), discovered by us (NKT), is the prototypical kidney organic anion (PAH) transporter responsible for the transport of many drugs (e.g., diuretics, antivirals, NSAIDs). Based on our in vivo studies of the Oat1 knockout mouse during the last project period and in vitro studies by us and others, OAT1 is now believed to be a central component of a proximal tubule sensing and elimination mechanism for gut microbe products and uremic toxins. Furthermore, recent data from our lab in rodents, as well as human studies by others, indicates that OAT1-dependent function is critical for residual kidney function in CKD. However, what is truly remarkable from our metabolomics and transcriptomics studies is the degree to which OAT1, which is almost exclusively expressed in the kidney, regulates systemic metabolism--beyond gut microbe products and uremic toxins. For example, it regulates many signaling lipids, citric acid cycle intermediates, bile acids, and vitamins/cofactors. Indeed, OAT1 may be the renal gene with the broadest effects on systemic metabolism. Although CKD is a multi-factorial disease, one of these factors is the metabolic consequence of the gradual loss of OAT1-dependent sensing and elimination as proximal tubule function declines. Thus, we hypothesize that, in CKD, the normal functioning of OAT1-mediated protein-bound metabolite sensing and signaling in the proximal tubule is severely disrupted--leading to major disruptions in small molecule metabolism and signaling. This is because of the endogenous role of OAT1 as a central component of a larger metabolic network involving gut microbe-derived metabolites, some of which participate in uremic toxicity in severe kidney disease but which also impact tryptophan and lipid metabolism as well as other metabolic processes. Using the latest approaches to integration of large omics datasets and a particularly novel multi-scale metabolic reconstruction approach (combining Recon3D with a genome-scale microbiome reconstruction), we will define the pathways in Oat1 KO mice under conditions in which: a) the gut microbiome is present or depleted; and b) kidney function is compromised. At the end, we will have fully analyzed combinations of Oat1 KO vs WT, healthy vs depleted gut microbiome, and sham operation vs 5/6 nephrectomy, as sampled in the serum, kidney, liver and feces. This will settle (in mice) the relative importance of each altered state on levels of uremic toxins, on biochemical pathways, and on overall multi-scale metabolic impact as determined by genome-scale metabolic reconstruction for each of the conditions. A portion of the omics data has already been obtained (KO effect, partial gut microbe effect). This project will thus produce a validated detailed map of OAT1-centered metabolism in normal physiology and in diseased states, possibly the first of its kind for any multi-specific “drug” transporter (Nigam, Nature Reviews Drug Discovery, 2015). The studies could lead to design of strategies for improving the metabolic abnormalities in CKD by affecting OAT1 function or expression.