High-throughput screening for modulators of vascular fat transport to treat and prevent diabetes

项目摘要/摘要 骨骼肌和其他组织的胰岛素抵抗(IR)是2型糖尿病发生的必由之路。 不完全氧化的非酯化脂肪酸(FAs)在肌肉细胞中过度积累，即脂毒性， 越来越多的人认识到它是IR发展的基础。同时，支链氨基酸(BCAA) 最近在糖尿病领域走在了前列和中心，因为在很大程度上是无偏见的代谢组学 前瞻性流行病学研究表明，血清支链氨基酸水平升高可预测胰岛素抵抗和糖尿病 早在临床表现前20年。我们现在已经发现了一种新的分子途径，它将 这两个观察结果。骨骼肌中支链氨基酸缬氨酸的主动分解代谢导致旁分泌 分泌代谢物3-羟基异丁酸酯(3-HIB)，促进FAs进入骨骼肌，以及 随之而来的脂肪毒性。 该通路的发现为胰岛素抵抗的潜在治疗提供了一个新的切入点， 与目前大多数以胰岛素为基础的或胰岛素分泌疗法正交。拟议的项目回应了 PA-16-374(用于发现疾病的治疗或显像剂的检测、开发和筛选 对NIDDK感兴趣)，并将确定靶向这一新发现的启用铅的小分子 路径。目的1用于硅胶和高通量筛选，以确定阻止3HIB产生的分子。 确定的点击率将通过一个强大的二级屏幕工作流程进行处理。在目标2中，分子 目标1中确定的药物将在完整细胞中进行有效性和安全性测试。在目标3中，验证了来自目标1和2的命中率 将首先提交体内药代动力学和药效学研究。可行的候选人将是 在3HIB治疗的小鼠以及在3HIB治疗前的小鼠中测试它们阻止脂肪堆积和胰岛素抵抗的能力 临床高脂饮食建立胰岛素抵抗模型。 拟议的工作代表着学术界和强大的私营部门团队之间的密切合作， 取得成功的悠久历史。我们提出了一个新的和具有挑衅性的假设，以及一个以前没有探索过的假设 了解和靶向脂毒性的方法。成功将产生新的目标和潜在的线索 用于开发解决胰岛素抵抗根源的新疗法的化合物。

PROJECT SUMMARY / ABSTRACT Insulin resistance (IR) in skeletal muscle and other tissues is obligatory for the development of type 2 diabetes. Excess accumulation of incompletely oxidized non-esterified fatty acids (FAs) in muscle cells, i.e., lipotoxicity, is increasingly appreciated to underlie the development of IR. In parallel, branched chain amino acids (BCAAs) have recently moved front and center in the field of diabetes, as unbiased metabolomic profiling in large prospective epidemiological studies has shown that serum elevations of BCAAs predict IR and diabetes as much as 20 years prior to clinical presentation. We have now uncovered a novel molecular pathway that links these two observations. Active catabolism of the BCAA valine in skeletal muscle causes the paracrine secretion of a metabolite, 3-hydroxyisobutyrate (3-HIB), which promotes entry of FAs into skeletal muscle, and subsequent lipotoxicity. The identification of this pathway provides a novel entry point for the potential treatment of insulin resistance, orthogonal to most current insulin-based or insulin secretogenic therapies. The proposed project responds to PA-16-374 (Assay Development and Screening to Discover Therapeutic or Imaging Agents for Diseases of Interest to the NIDDK) and will identify lead-enabling small molecules that target this newly discovered pathway. Aim 1 use in silico and high-throughput screening to identify molecules that block production of 3HIB. Identified hits will be taken through a robust workflow of secondary counterscreens. In Aim 2, the molecules identified in Aim 1 will be tested for efficacy and safety in intact cells. In Aim 3, validated hits from Aims 1 and 2 will first be submitted to in vivo pharmacokinetic and pharmacodynamic studies. Viable candidates will then be tested for their ability to block lipid accumulation and insulin resistance in 3HIB-treated mice as well as in a pre- clinical high-fat fed model of insulin resistance. The proposed work represents a close collaboration between academia and a strong private sector team with a long history of successes. We propose a novel and provocative hypothesis, and a previously unexplored approach to understand and target lipotoxicity. Success would yield novel targets and potential lead compounds for the development of new therapeutics that address the root of insulin resistance.