Investigating the role of uptake and metabolism in the mechanism of action of the drug N-acetyl-leucine

N-乙酰亮氨酸（NAL）是氨基酸亮氨酸的乙酰化形式。最初用于治疗急性眩晕，现在有强烈的兴趣将这种药物重新用于其他未满足医疗需求的神经系统疾病。潜在的应用包括溶酶体贮积症C型尼曼-皮克病（NPC），其III期临床试验已于2023年成功完成（NCT 05163288）。NAL是手性分子，以L和D对映体存在。L型是临床开发的主要关注点，尽管D型可引起某些治疗作用（卡亚等人，2021）。尽管它的治疗前景，NAL的作用机制仍然不完全清楚。该项目旨在促进我们对NAL的机制理解，从而提供一个合理的框架，以扩大其在罕见和常见神经系统疾病中的应用，并可能为新药的开发提供信息。工作假设是NAL是亮氨酸的前药，通过亮氨酸或其代谢物起作用。NAL治疗的广泛结果可能是使细胞能量产生正常化，其已显示在NPC中失调（Kennedy et al，2013）。实验数据还表明，NAL的细胞摄取利用单羧酸转运蛋白（MCT），而不是亮氨酸使用的L型氨基酸转运蛋白（LAT 1）（丘吉尔等人，2021）。这可能具有重要的机制意义：例如，MCT动力学可以通过亮氨酸代谢的通常次要途径增强相对通量。我们将测试几个独立的，但相互关联的假设NAL的机制。该项目的主要目标如下：1.检测转运蛋白摄取在NAL 2作用机制中的作用。确定NAL 3的代谢命运。为了测试代谢在NAL作用机制中的作用，实验技术将包括分子和细胞生物学方法、药理学抑制剂的使用、流式细胞术、成像/显微镜、液相色谱法和质谱法。技能发展领域将包括定量技能，如统计分析，科学沟通技能的发展，以及必要时的体内工作培训。

N-acetyl-leucine (NAL) is an acetylated form of the amino acid leucine. Originally used as a treatment for acute vertigo, there is now intense interest in repurposing this drug for other neurological disorders with unmet medical needs. Potential applications include the lysosomal storage disorder Niemann-Pick disease Type C (NPC), for which a successful phase III clinical trial was completed in 2023 (NCT05163288). NAL is a chiral molecule, existing as L and D enantiomers. The L form is of primary interest for clinical development, although the D form can elicit certain therapeutic effects (Kaya et al, 2021). Despite its therapeutic promise, the mechanism of action of NAL remains incompletely understood. This project aims to contribute to our mechanistic understanding of NAL, thereby providing a rational framework to expand its use in rare and common neurological disorders and potentially informing the development of new drugs. The working hypothesis is that NAL is a prodrug of leucine, acting via leucine or its metabolites. A broad outcome of NAL treatment may be to normalise cellular energy production, which has been shown to be dysregulated in NPC (Kennedy et al, 2013). Experimental data also indicate that cellular uptake of NAL utilises a monocarboxylate transporter (MCT) rather than the L-type amino acid transporter (LAT1) used by leucine (Churchill et al, 2021). This may have important mechanistic implications: for example, MCT kinetics could enhance the relative flux through ordinarily minor pathways of leucine metabolism. We will test several independent but interrelated hypotheses regarding the mechanism of NAL. Central aims of the project are as follows:1. To test the role of uptake by a transporter in the mechanism of action of NAL2. To determine the metabolic fate of NAL3. To test the role of metabolism in the mechanism of action of NALExperimental techniques will include molecular and cell biology methods, the use of pharmacological inhibitors, flow cytometry, imaging/microscopy, liquid chromatography and mass spectrometry. Areas of skill development will include quantitative skills such as statistical analysis, development of scientific communication skills, and training for in vivo work if required.