Adaptive Regulation of Vitamin B1 Transport

维生素 B1 运输的适应性调节

• 批准号: 8430562
• 负责人: Jason A Zastre
• 金额: $ 17.69万
• 依托单位: UNIVERSITY OF GEORGIA
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-06-02 至 2015-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8430562
• 关键词: Alcohol consumption; Alcohol dependence; Alcoholism; Alcohols; Attenuated; Bioenergetics; Biological Assay; Cells; Coenzymes; Country; Data; Developing Countries; Dietary intake; Disease; Disease Progression; Down-Regulation; Enzymes; Ethanol Metabolism; Future; Gene Expression; Gene Expression Regulation; Goals; Homeostasis; Human; Hypoxia; Impairment; Intestines; Kidney; Knowledge; Laboratories; Lactic Acidosis; Lead; Link; Luciferases; Malnutrition; Mediating; Metabolic; Metabolic stress; Metabolism; Mission; Neurologic; Nutritional; Outcome; Oxidative Stress; Pathology; Pathway interactions; Process; Promoter Regions; Public Health; Pyruvate; Regulation; Regulatory Element; Research; Response Elements; Stress; Testing; Thiamine; Thiamine Deficiency; Trans-Activators; Transcriptional Regulation; Transport Process; Up-Regulation; Work; absorption; base; chronic alcohol ingestion; hypoxia inducible factor 1; innovation; insight; mitochondrial dysfunction; nutrition; promoter; public health relevance; transcription factor; uptake

DESCRIPTION (provided by applicant): Vitamin B1 (thiamine) is a critical enzyme cofactor within the glycolytic metabolism network that is fundamentally required to sustain the bioenergetic and anabolic needs of all cells. When deficiencies arise, an adaptive up-regulation in thiamine transporter expression has been described that attempts to restore thiamine homeostasis. However, thiamine deficiencies during chronic alcohol consumption are associated with a down- regulation of thiamine transporters. This antagonism between alcohol and thiamine availability on gene regulation of thiamine transporters is not clearly understood because there is a lack of fundamental knowledge on how thiamine transporters are adaptively regulated. Hence, this application endeavors to understand the cis- and trans-regulatory elements that are responsible for mediating an adaptive up-regulation during thiamine deficiency. Until this mechanistic insight into adaptive regulation is known, understanding how alcohol attenuates the gene expression of thiamine transporters during associated thiamine deficiency will not be realized. The overall objective we have for this application is to determine the transcriptional pathways involved in the adaptive regulation of thiamine transporters during thiamine deficiency. It is our central hypothesis that hypoxia inducible factor-1 (HIF-1 is a centrl transcription factor modulating thiamine availability by trans- activating expression of the thiamine transporter SLC19A3. This hypothesis has been formulated on the basis of preliminary data produced in the applicants' laboratory. The rationale for the proposed research is that once the transcriptional pathways for adaptive thiamine transporter expression are known, new insights and approaches into the underlying effects of alcohol consumption on thiamine transport capacity can be achieved. Guided by our strong preliminary data, this hypothesis will be tested by pursuing two specific aims: 1) Establishing the connection between thiamine deficiency and pseudo-hypoxia on adaptive thiamine transport expression. It is our contention that the metabolic consequences of thiamine deficiency can lead to an accumulation of pyruvate which in turn activates HIF-1 mediated gene regulation. Thus we will use a combination of metabolic profiling and assessment of HIF-1 target gene expression and in particular SLC19A3 during thiamine deficiency. We will also determine if the consequences of alcohol metabolism attenuates the level of pyruvate to counteract this adaptive regulation. 2) Determining HIF-1 mediated trans- activation of SLC19A3 gene expression. Our working hypothesis is that adaptive up-regulation of the thiamine transporter SLC19A3 is conferred through hypoxia response elements in the proximal promoter region. Using a combination of promoter-luciferase assays and ChIP we will establish HIF-1 as an essential trans-activator for SLC19A3 expression. Overall, the proposed research is significant because it is expected to lead to a mechanistic understanding of thiamine transporter regulation within thiamine deficiency related disorders.

描述（由申请人提供）：维生素B1（硫胺素）是糖酵解代谢网络中的关键酶辅因子，从根本上需要维持所有细胞的生物能和合成代谢需求。当出现缺陷时，已经描述了硫胺素转运蛋白表达的自适应上调，该表达试图恢复硫胺素稳态。然而，慢性饮酒期间的硫胺素缺乏与硫胺素转运蛋白的下调有关。酒精和硫胺素可用性对硫胺素转运蛋白的基因调节之间的拮抗作用尚不清楚，因为缺乏关于硫胺素转运蛋白如何适应调节的基本知识。因此，这项应用程序努力理解负责介导硫胺素缺乏期间自适应上调的顺式和反式调节元素。直到已知对适应性调节的机械性见解之前，了解酒精如何减弱相关硫胺素缺乏期间硫胺素转运蛋白的基因表达。我们对此应用的总体目标是确定 硫胺素缺乏期间硫胺素转运蛋白的适应性调节涉及的转录途径。我们的中心假设是，缺氧诱导因子1（HIF-1是一种通过转移硫胺素转运蛋白转运蛋白SLC19A3的表达来调节硫胺素可用性的中心转录因子。该假说是根据申请人的拟议throine the News throway the News throwey the News throwey the News threove the Protimention the News throwey的提出的。可以通过我们强大的初步数据来指导饮酒对硫胺素运输能力的潜在影响的见解和方法，该假设将通过追求两个具体的目的来检验：1）确定硫胺素缺乏症与伪氧化的硫胺素运输表达。我们的论点是，硫胺素缺乏的代谢后果会导致丙酮酸的积累，进而激活HIF-1介导的基因调节。因此，我们将使用HIF-1靶基因表达，尤其是硫胺素缺乏期间的SLC19A3的代谢分析和评估的组合。我们还将确定酒精代谢的后果是否会减弱丙酮酸的水平以抵消这种适应性调节。 2）确定HIF-1介导的SLC19A3基因表达的转移。我们的工作假设是，硫胺素转运蛋白SLC19A3的自适应上调是通过近端启动子区域中的缺氧响应元素赋予的。使用启动子 - 卢西酶测定和芯片的组合，我们将建立HIF-1作为SLC19A3表达的必不可少的反式激活剂。总体而言，拟议的研究很重要，因为预计它将导致对硫胺素缺乏症中硫胺素转运蛋白调节的机械理解。