Glycerol Kinase Deficiency as a Model to Understand Met*

描述（由申请人提供）：这些研究的长期目标是了解单基因疾病（甘油激酶缺乏症）如何导致复杂表型疾病的细胞机制。甘油激酶（GK）催化甘油磷酸化为3-磷酸甘油，并处于葡萄糖和脂肪代谢的界面。甘油激酶缺乏症（GKD）是一种X-连锁代谢疾病，是由于甘油激酶基因（GK）的突变和/或缺失。GKD患者在表型上有症状或无症状。我们对甘油激酶缺乏症的初步研究表明，没有办法通过GK活性或蛋白质三维结构模型中突变的位置来预测哪些患者有症状，哪些患者无症状。我们推测，这是GK突变与其他遗传和环境对代谢通量（相关途径中的其他酶和关键中间体水平）的影响的相互作用，这对了解这种疾病的发病机制很重要。 该提案的目标是更好地了解细胞内的复杂相互作用，以及单个酶（GK）的扰动如何影响其他途径和基因表达，从而导致整个动物中观察到的生理变化。我们的第一个具体目标（任务1）是使用来自GKD个体以及正常个体的淋巴母细胞系来表征与GK相关的代谢途径以及它们在GKD中如何变化。代谢组分析、通量分析和转录组分析将使我们能够在个体遗传背景的背景下研究具有不同水平GK活性的突变的影响。然后，我们将研究这些突变在肝脏和肾脏细胞系中的作用，因为这些组织具有最高水平的GK表达，并将使我们能够研究GK突变在相同遗传背景背景下的作用。这些研究的结果将使我们能够使用甘油激酶敲除（gyk k/o）小鼠（特定目标/任务2）在整个动物模型中进行代谢组、通量和转录组分析。这些研究将提供一个模型系统，以了解遗传疾病的复杂性，并最终帮助治疗这些疾病。

DESCRIPTION (provided by applicant): The long-term objectives of these investigations are to understand the cellular mechanisms of how a single gene disorder (glycerol kinase deficiency) causes a complex phenotypic disease. Glycerol kinase (GK) catalyzes the phosphorylation of glycerol into glycerol 3-phosphate and is at the interface of glucose and fat metabolism. Glycerol kinase deficiency (GKD) is an X-linked disorder of metabolism that is due to mutations and/or deletions of the glycerol kinase gene (GK). Patients with GKD are phenotypically either symptomatic or asymptomatic. Our initial work on glycerol kinase deficiency has shown that there is no way to predict which patients will be symptomatic and which will be asymptomatic by GK activity or the location of the mutation in a model of the three dimensional structure of the protein. We hypothesize that it is the interaction of GK mutations with additional genetic and environmental influences on metabolic flux (other enzymes in related pathways and levels of critical intermediates) that are important to understand the pathogenesis of this disorder. The goals of this proposal are to understand better the complex interactions within the cell and how perturbations of an individual enzyme (GK) affects the other pathways and gene expression to result in the physiological changes seen in the whole animal. Our first Specific Aim (Task 1) is to characterize the metabolic pathways relating to GK and how they are changed in GKD using lymphoblastoid cells lines from the individuals with GKD as well as normal individuals. Metabolome analysis, flux analysis, and transcriptome analysis will allow us to investigate the effect of the mutations with varying levels of GK activity in the context of the individuals' genetic background. We will then investigate the effect of these mutations in liver and kidney cell lines as these tissues have the highest level of GK expression and will allow us to investigate the role of the GK mutations within the context of identical genetic background. Results of these studies will allow us to perform metabolome, flux, and transcriptome analysis in the whole animal model using the glycerol kinase knock-out (gyk k/o) mouse (Specific Aim/Task 2). These studies will provide a model system to understand the complex nature of genetic disorders and eventually help in treatment of such disorders.