Deciphering Mechanisms of Nitrogen-Containing Bisphosphonates - Admin Supplement

摘要 骨质疏松症和低骨量（骨质减少）估计影响55%的美国人口 年龄在50岁以上;总共超过5000万人，对患者的生活质量产生重大影响。的 目前骨质疏松症的标准治疗是施用含氮的二膦酸盐（NBP）。 然而，这些高电荷药物进入、穿过并到达其分子的机制是不确定的。 人们对靶细胞的靶点和作用知之甚少。这项提案的长期目标是解构 NBP反应所必需的分子途径。为了做到这一点，我们将建立在初步遗传研究的基础上， 使用细胞测定和小鼠模型，以及体外结合和功能测定来探索 NBP和我们确定的目标之间的相互作用。我们以前的工作利用了两个不同的高通量 全基因组筛选，以确定NBP作用所需的200多个基因。我们最初的重点是 已经对两种基因ATRAID和SLC37A3的作用进行了研究，这两种基因强烈影响对NBP的反应， 并且很可能是这些药物的内吞运输所需要的。本建议以此为基础，以i） 剖析ATRAID和SLC37A3如何促进NBP运输及其细胞功能，ii）研究ATRAID和SLC37A3的作用。 两种转录因子，通过GWAS与BMD的变化相关，当耗尽时可能使细胞敏感， NBP的作用，和iii）使用条件性ATRAID敲除小鼠，研究NBP的作用机制。 这些药物是治疗骨转移的药物。总之，这些研究产生了一个更广泛的图片， NBP用于影响细胞和组织的分子途径。该提案侧重于已确定的 基因，并将为未来的工作奠定基础，确定在药物筛选中识别的基因如何预测 患者对NBP的反应，包括治疗效果、所需NBP剂量和不良副作用。 此外，这一重点是了解一种廉价的，常用的处方药的机制， 为骨质疏松症治疗策略的发展带来新的视角和假设。

Abstract Osteoporosis and low bone mass (osteopenia) are estimated to affect 55 percent of the American population over the age of 50; over 50 million people in total, with major consequences for the patients’ quality of life. The current standard treatment for osteoporosis is administration of nitrogen-containing bisphosphonates (NBPs). However, the mechanism by which these highly-charged drugs enter, traffic through, and reach their molecular targets and effect target cells is poorly understood. The long-term goal of this proposal is to deconstruct the molecular pathways essential for NBP response. To do this, we will build upon preliminary genetic studies by using cell assays and mouse models, as well as in vitro binding and functional assays to explore the interactions between NBPs and our identified targets. Our previous work utilized two distinct high-throughput genome-wide screens to identify over 200 genes required for the action of NBPs. The initial focus of our studies has been on the role of two genes, ATRAID and SLC37A3, that strongly affect the response to NBPs, and are likely to be required for the endocytic trafficking of these drugs. This proposal builds upon this to i) dissect how ATRAID and SLC37A3 facilitate NBP trafficking and their cellular function, ii) investigate the role of two transcription factors, associated by GWAS with changes in BMD, that when depleted may sensitize cells to the effects of NBPs, and iii) using conditional ATRAID knockout mice, investigate the mechanism by which these drugs are therapeutic for bone metastases. Together, these studies generate a broader picture of the molecular pathways that NBPs use to affect cells and tissues. This proposal focuses on a subset of identified genes, and will set the stage for future work determining how genes identified in drug screens may predict patient response to NBPs, including efficacy of treatment, dosage of NBPs needed, and adverse side effects. Moreover, this focus on understanding the mechanisms of an inexpensive, commonly prescribed drug will bring new perspectives and hypotheses to the development of treatment strategies for osteoporosis.