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

项目总结/摘要 骨骼肌和其他组织中的胰岛素抵抗（IR）对于2型糖尿病的发展是必须的。 肌肉细胞中不完全氧化的非酯化脂肪酸（FA）的过量积累，即，脂毒性， 越来越多的人认识到这是IR发展的基础。同时，支链氨基酸（BCAA） 最近在糖尿病领域的前沿和中心，作为大规模无偏见的代谢组学分析， 前瞻性流行病学研究表明，血清支链氨基酸升高可预测IR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， 这两个观察。BCAA缬氨酸在骨骼肌中的主动催化引起旁分泌 代谢物3-羟基异丁酸酯（3-HIB）的分泌，其促进FA进入骨骼肌，和 随后的脂毒性。 该途径的鉴定为胰岛素抵抗的潜在治疗提供了新的切入点， 与大多数目前的基于胰岛素或胰岛素分泌原疗法正交。拟议项目响应 PA-16-374（用于发现治疗或成像药物的试验开发和筛选， 感兴趣的NIDDK），并将确定铅使小分子，针对这一新发现的 通路目的1利用计算机模拟和高通量筛选来鉴定阻断3 HIB产生的分子。 已确定的命中将通过二级反屏幕的强大工作流程进行。在目标2中，分子 将在完整细胞中测试目标1中鉴定的化合物的功效和安全性。在目标3中，目标1和2的确认命中率 将首先进行体内药代动力学和药效学研究。可行的候选人将在 测试了它们在3 HIB处理的小鼠以及预处理的小鼠中阻断脂质积累和胰岛素抵抗的能力。 临床高脂喂养胰岛素抵抗模型。 拟议的工作代表了学术界和强大的私营部门团队之间的密切合作， 有着悠久的成功历史。我们提出了一个新的和挑衅性的假设，和一个以前未探索的 了解和靶向脂毒性的方法。成功将产生新的目标和潜在的铅 这些化合物用于开发解决胰岛素抵抗根源的新疗法。

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.