Elucidating the mechanism of transendothelial fatty acid transport

阐明跨内皮脂肪酸转运机制

• 批准号: 389324783
• 负责人: Professor Dr. Joachim Füllekrug
• 金额: --
• 依托单位: Klinik für Gastroenterologie, Infektionskrankheiten, Vergiftungen
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/389324783?language=en
• 关键词: Elucidating; mechanism; transendothelial; fatty; acid

Fatty acids and the lipids made from them are essential components of every cellular form of life. Exogenous fatty acids are taken up by transport across the plasma membrane, and this is usually followed very soon by their esterification with coenzyme A. This "activation" of fatty acids is indispensable for their further metabolism. In our published preliminary work we have characterized several membrane proteins involved in cellular fatty acid uptake, especially putative transporter proteins (FATPs and CD36) and fatty acyl-CoA ligases. Now we would like to use the developed molecular tools thereby to address the most urgent open questions in this still very controversial field of research, in particular the relationship between fatty acid transport and metabolism. The model system is going to be peripheral microvascular endothelial cells which are distinguished by a high capacity for fatty acid uptake and transport.The overall key question of this proposal is: Which is the molecular mechanism for the favored transport of fatty acids across the endothelium as opposed to their metabolism by the endothelial cells? Driving forces for the transport of fatty acids are in principle: regulation by fatty acid transport proteins, concentration differences between luminal and abluminal endothelial plasma membrane, higher velocity of transport as compared to metabolism, and the protection of non-esterified fatty acids against the cytosolically oriented CoA ligases. These hypotheses will be examined by the work program, and correlated to each other. The expression level of the candidate proteins is going to be modified by retrovirus mediated RNA interference or overexpression respectively. Immortalized as well as primary cultures of endothelial cells will be differentiated on permeable filters to be able to measure fatty acid transport and metabolism simultaneously. The focused project aims derived from the hypotheses are:1. Elucidation of the mechanism of action of the FATP transporters.2. Identification of the underlying dominant determinants for the high velocity of fatty acid transport as compared to endothelial metabolism.3. Investigation if cytosolic proteins or caveolae protect non-esterified fatty acids from the metabolic enzymes.Summarizing, endothelial cells are a unique model system which are excellently suited to answer basic and important questions regarding cellular fatty acid transport. We assume that our results will also be relevant for the transport across the blood brain barrier as well as for the understanding of widespread lipid associated metabolic diseases.

脂肪酸和由它们制成的脂质是每种细胞生命形式的基本组成部分。外源性脂肪酸通过跨质膜转运而被吸收，通常很快就被辅酶A酯化。脂肪酸的这种“活化”对于它们的进一步代谢是必不可少的。在我们发表的初步工作中，我们表征了几种参与细胞脂肪酸吸收的膜蛋白，特别是推定的转运蛋白（FATP和CD 36）和脂肪酰CoA连接酶。现在，我们想使用发达的分子工具，从而解决最紧迫的开放问题，在这个仍然非常有争议的研究领域，特别是脂肪酸运输和代谢之间的关系。模型系统将是外周微血管内皮细胞，其特征在于具有高的脂肪酸摄取和转运能力，该提议的总体关键问题是：与内皮细胞的代谢相反，哪种分子机制有利于脂肪酸穿过内皮细胞的转运？原则上，脂肪酸转运的驱动力是：脂肪酸转运蛋白的调节、腔和近腔内皮细胞质膜之间的浓度差异、与代谢相比更高的转运速度以及保护非酯化脂肪酸免受胞质定向CoA连接酶的影响。这些假设将通过工作计划进行检查，并相互关联。候选蛋白的表达水平将分别通过逆转录病毒介导的RNA干扰或过表达来修饰。内皮细胞的永生化以及原代培养物将在可渗透过滤器上分化，以便能够同时测量脂肪酸转运和代谢。由假设导出的项目目标是：1。阐明FATP转运蛋白的作用机制。与内皮代谢相比，确定脂肪酸高速度转运的潜在主导决定因素。研究胞浆蛋白或小窝是否保护非酯化脂肪酸免受代谢酶的侵害。总之，内皮细胞是一种独特的模型系统，非常适合回答有关细胞脂肪酸转运的基本和重要问题。我们认为，我们的研究结果也将是相关的跨血脑屏障的运输，以及广泛的脂质相关的代谢疾病的理解。