Effects of cellular lipid droplet allocation on lipid droplet consumption and Drosophila embryogenesis

细胞脂滴分配对脂滴消耗和果蝇胚胎发生的影响

• 批准号: 10056973
• 负责人: Marcus Daniel Kilwein
• 金额: $ 4.55万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-01 至 2022-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10056973
• 关键词: Active Biological Transport; Address; Affect; Animals; Area; Biology; Blastoderm; Cell Culture System; Cell Culture Techniques; Cells; Cellular biology; Complex; Consumption; Cultured Cells; Data; Deposition; Development; Developmental Delay Disorders; Disease; Drosophila genus; Embryo; Embryonic Development; Energy Intake; Energy Supply; Energy-Generating Resources; Fatty Liver; Fatty acid glycerol esters; Fertilization; Genetic; Goals; Growth; Knock-out; Link; Lipase; Lipids; Lipolysis; Liver diseases; Mammalian Cell; Mammals; Mediating; Medical; Metabolic; Metabolism; Microtubules; Mitochondria; Motor; Mus; Non-Insulin-Dependent Diabetes Mellitus; Nutrient; Nutritional status; Obesity; Organelles; Organism; Positioning Attribute; Property; Proteins; Regulation; Research; Role; Starvation; Structure; System; Testing; Time; Toxic effect; Triglycerides; base; blastomere structure; experience; fly; hatching; human disease; lipid metabolism; lipid transport; mutant; prevent; response; tool

Lipid droplets have recently emerged as an exciting, disease relevant topic of research. Droplet biology is intrinsically linked to fat metabolism, which is in turn linked to a multitude of human diseases despite the obvious medical importance of lipid droplets, much of their cellular biology is poorly understood. It has recently become clear that throughout the animal kingdom lipid droplets are transported within the cell. It appears that the cellular region a lipid droplet is positioned to affects its metabolic state allowing cells to transport droplets into a ‘degradative region’ when starved or a ‘growth region’ when fed. Testing this hypothesis and examining the overall importance of lipid droplet allocation in the developmental system of the Drosophila embryo is the goal of this proposal. It is the Drosophila embryo where our mechanistic understanding of how lipid droplets are transported is the most advanced. While the impetus of previous such research was to understand general properties of active transport, I will now employ this system to droplet biology. The decades of transport driven research done by our lab has yielded a vast repertoire of genetic tools which I plan to utilize to interrogate the role transport mediated lipid droplet allocation between embryonic cells. My preliminary data shows that disrupting proper transport of lipid droplets along microtubules diminishes turnover of triglycerides (stored in lipid droplets) and may cause a delay in embryonic development. Intriguingly, droplet consumption because of improper intracellular positioning fits nicely with data gathered from mammalian systems: mouse embryos extensively reposition their lipid droplets post fertilization and mammalian cultured cells use microtubules to reposition droplets depending on nutritional status. These strong similarities between mammals and flies not only suggests conservation of transport mediated positioning of lipid droplets across taxa, but also supports the notion that lipid droplet positioning itself may be a means regulating cellular lipid metabolism. I will test this at an organismal level. This proposal aims to address why loss of lipid droplet based active transport impedes their consumption and how that that failed consumption would then delay embryonic development. It seems likely that improperly allocating droplets would cause a state of relative starvation in droplet-deprived cells. Mammalian cell culture system have elucidated several markers of cellular lipid starvation which I will examine in these lipid droplet deprived embryos. Next, the delay in embryogenesis is likely caused by diminished droplet consumption at the embryonic level which would globally diminish the energy supply. To pin this down, I will use a panel of genetic mutants, which fail in lipid droplet allocation to varying degrees, to extrapolate the relationship between failed lipid droplet consumption and delayed embryogenesis. These studies would constitute strong support of the role of lipid-droplet-transport-mediated cellular allocation and its importance for development.

最近，脂滴已经成为一个令人兴奋的、与疾病相关的研究课题。水滴生物学是 本质上与脂肪新陈代谢有关，这反过来又与许多人类疾病有关，尽管 尽管脂滴具有明显的医学重要性，但人们对其细胞生物学知之甚少。最近是这样的 很明显，在整个动物界，脂滴都是在细胞内运输的。看起来， 脂滴所处的细胞区域，影响其新陈代谢状态，使细胞能够运输液滴 饥饿时变成“退化区域”，进食时变成“生长区域”。检验这一假说并检验 果蝇胚胎发育系统中脂滴分配的总体重要性是 这项提案的目标。在果蝇胚胎中，我们对脂滴如何 是最先进的运输方式。虽然以前这类研究的动力是理解一般的 主动运输的特性，我现在将使用这个系统来研究液滴生物学。几十年的交通运输驱动 我们实验室的研究已经产生了大量的遗传工具，我计划用它们来审问 角色转运介导的脂滴在胚胎细胞间的分配。我的初步数据显示 破坏脂滴沿微管的正常运输会减少甘油三酯的周转(储存在 脂滴)，并可能导致胚胎发育延迟。耐人寻味的是，由于 不正确的细胞内定位与从哺乳动物系统收集的数据非常吻合：小鼠胚胎 受精后广泛重新定位脂滴，哺乳动物培养细胞使用微管 根据营养状况重新放置液滴。哺乳动物和苍蝇之间的这些强烈的相似之处 这不仅表明了脂滴跨类群的运输调节定位的保守性，而且也支持 认为脂滴定位本身可能是调节细胞脂代谢的一种手段。我将在以下位置进行测试 生物体的水平。该提案旨在解决基于脂滴的丢失阻碍主动转运的原因 他们的消费，以及这种失败的消费如何会推迟胚胎发育。似乎 不适当地分配液滴很可能会导致没有液滴的细胞处于相对饥饿的状态。 哺乳动物细胞培养系统已经阐明了细胞脂肪饥饿的几个标志，我将对这些标志进行检测 在这些没有脂滴的胚胎中。其次，胚胎发育的延迟很可能是由于 水滴消费处于萌芽阶段，这将减少全球能源供应。为了弄清这件事， 我将使用一组基因突变，它们在不同程度上未能分配脂滴，来推断 脂滴消耗失败与胚胎发育延迟的关系。这些研究将 构成强大支持作用的脂滴转运介导的细胞分配及其 对发展的重要性。