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: 10200107
• 负责人: Marcus Daniel Kilwein
• 金额: $ 4.6万
• 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/10200107
• 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.

脂质液滴最近成为一个令人兴奋的，疾病相关的研究主题。液滴生物学是 与脂肪代谢有本质上的联系，而脂肪代谢又与多种人类疾病有关 脂质液滴的显而易见的医学重要性，它们的大部分细胞生物学知识都很少。最近有 清楚地表明，在整个动物界，脂质液滴都在细胞内运输。看来 细胞区域A脂质液滴的位置可影响其代谢状态，从而使细胞运输液滴 当饥饿或喂食时，进入“降解区域”或“生长区域”。检验这一假设并进行检查 脂质液滴分配在果蝇胚胎的发育系统中的总体重要性是 该提议的目标。它是果蝇的胚胎，我们对脂质液滴的理解 运输是最先进的。虽然以前的研究的推动力是了解一般 主动运输的属性，我现在将使用该系统来液滴生物学。数十年的运输驱动器 我们实验室所做的研究产生了大量的遗传工具，我计划用来询问该工具 角色转运介导的胚胎细胞之间的脂质液滴分配。我的初步数据表明 破坏沿微管的脂质液滴的正确运输减少甘油三酸酯的营业额（存储在 脂质液滴），可能会导致胚胎发育的延迟。有趣的是，由于 细胞内定位不当与从哺乳动物系统收集的数据非常适合：小鼠胚胎 在受精后广泛重新定位其脂质液滴，哺乳动物培养的细胞使用微管 重新定位液滴取决于营养状况。哺乳动物和苍蝇之间的这些强烈相似之处 仅建议保存在分类单元中脂质液滴的运输介导定位，但也支持 脂质液滴定位本身可能是控制细胞脂质代谢的一种手段。我会在 有机水平。该建议旨在解决为什么基于脂质液滴的主动运输阻碍的损失 他们的消费以及失败的消费如何将延迟胚胎发育。它似乎 也许不当分配液滴会导致液滴剥夺细胞的相对饥饿状态。 哺乳动物细胞培养系统阐明了细胞脂质饥饿的几个标记 在这些脂肪液滴中被剥夺的胚胎。接下来，胚胎发生的延迟可能是由于减少 胚胎水平的液滴消耗将在全球范围内降低能源供应。将其固定下来， 我将使用一组基因突变体，该突变体在脂质液滴分配中失败，以推断 失败的脂质液滴消耗与延迟的胚胎发生之间的关系。这些研究会 构成了脂质 - 滴滴 - 传输介导的细胞分配及其的作用的强烈支持 对发展的重要性。