Deciphering the lipid composition of primary cilia in human metabolic disease

破译人类代谢疾病中初级纤毛的脂质成分

• 批准号: 10696465
• 负责人: Maia Kinnebrew
• 金额: $ 38.71万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-20 至 2028-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10696465
• 关键词: Acceleration; Address; Adipocytes; Admission activity; Adult; Affect; Animals; Area; Automobile Driving; Award; Binding; Biochemical; Biochemistry; Biological; Biology; Biophysics; Brain; Cell membrane; Cell surface; Cells; Cellular biology; Cholesterol; Cilia; Classification; Consumption; Dedications; Defect; Development; Developmental Biology; Diabetes Mellitus; Diet; Dietary Fats; Doctor of Philosophy; Educational Status; Electron Spin Resonance Spectroscopy; Ensure; Environment; Event; Faculty; Faculty Workshop; Fatty Acids; Financial Support; G Protein-Coupled Receptor Signaling; G-Protein-Coupled Receptors; Genetic; Genetic study; Goals; Health; Health Care Costs; Homeostasis; Human; Human Genetics; Human Resources; In Vitro; Institution; Islet Cell; Islets of Langerhans; Laboratories; Lead; Leadership; Link; Lipids; Measures; Membrane; Membrane Biology; Mentors; Mentorship; Metabolic Diseases; Metabolism; Methodology; Molecular; Mus; Non-Insulin-Dependent Diabetes Mellitus; Obesity; Organelles; Pathway interactions; Perception; Persons; Play; Postdoctoral Fellow; Privatization; Process; Property; Proteins; Reader; Receptor Signaling; Recording of previous events; Research; Research Personnel; Research Training; Resource Sharing; Role; Satiation; Series; Signal Transduction; Spectrum Analysis; Stimulus; Structure; Students; Syndrome; System; Talents; Techniques; Testing; Time; Training; Universities; Vision; Visualization; Voting Right; Work; biological research; career; ciliopathy; cost; equipment acquisition; experience; extracellular; graduate school; high school; in vivo; instrument; insulin secretion; interest; lipid biosynthesis; lipid transport; medical schools; meetings; member; minority student; novel; peer; programs; receptor; recruit; skills; success; symposium; tissue culture; tool; trafficking; transmission process; undergraduate student

PROJECT SUMMARY The primary cilium is a cell surface organelle that plays critical roles in human health. Multiple G protein-coupled receptors (GPCRs) are trafficked to the primary cilium where they carry extracellular signals across the membrane to initiate intracellular signaling events. Genetic studies have linked GPCR signaling at primary cilia to human metabolic disease. For example, ciliary GPCRs regulate diverse metabolic processes such as the perception of satiety, the secretion of insulin, and the formation of adipocytes. With 42% of U.S. adults classified as obese, understanding how the primary cilium functions as a GPCR signaling center is critical to addressing this major human health concern. In this proposal I will test how the primary cilium membrane composition controls GPCR signaling. Lipids have profound effects on GPCR signaling through (1) direct binding and (2) indirect modulation by changing membrane bilayer properties. Through these interactions, GPCRs play fundamental roles in cellular lipid signaling and organismal lipid homeostasis. A key barrier to understanding how GPCRs regulate human metabolism is the lack of tools to study lipids in cells. I have developed a unique skillset and a set of tools to visualize, quantify and manipulate lipids at primary cilia to address these challenges. This proposal tests three fundamental questions related to cilia lipid signaling. First, despite its importance in regulating metabolism, it is unknown whether the primary cilia membrane is altered by dietary lipids. External stimuli robustly change the plasma membrane (PM) composition to drive cell signaling events required for cellular homeostasis. To test this at cilia, I will treat cells with fatty acids or cholesterol to mimic the human diet and ask whether the membrane composition is altered. Cilia lipids will be further examined in mice fed different chow diets and in mice with metabolic disease (Aim 1). Second, despite having a membrane that is structurally continuous with the PM, the primary cilium maintains a distinct membrane composition that is critical for GPCR signaling through unknown mechanisms. I will test whether lipids exchange between the PM and cilia membrane, and then determine how lipids are delivered to cilia by disrupting membrane trafficking pathways (Aim 2). Finally, I will determine what lipids are required for FFAR4 activity at cilia. FFAR4 is a GPCR that intimately relies on the integrity of the cilia membrane environment for signaling. By cross comparing this screen with a screen I previously performed to find regulators of the ciliary GPCR SMO, I will identify generalizable pathways controlling ciliary lipid homeostasis. Importantly, this screen will also determine the specific lipid requirements of FFAR4, which is a promising target for treating metabolic disease due to its role in insulin secretion and adipogenesis. Through this research I will develop robust methodologies that can be utilized to study cilia in diverse contexts, and I will advance our understanding of cilia biology, membrane biology, and GPCR signaling. The long-term vision of this project is to identify new strategies for correcting lipid or GPCR signaling defects found in human metabolic disease.

项目摘要 初级纤毛是细胞表面的细胞器，在人类健康中起着关键作用。多G蛋白偶联 受体（GPCR）被运输到初级纤毛，在那里它们携带细胞外信号穿过纤毛。 膜启动细胞内信号事件。遗传研究将初级纤毛的GPCR信号联系起来 to human人类metabolic代谢disease疾病.例如，睫状GPCR调节多种代谢过程，如 饱腹感、胰岛素分泌和脂肪细胞的形成。42%的美国成年人 作为肥胖者，了解初级纤毛如何作为GPCR信号中心发挥作用对于解决 这是人类健康的主要问题。在这个建议中，我将测试初级纤毛膜的组成， 控制GPCR信号传导。脂质通过（1）直接结合和（2） 通过改变膜双层性质的间接调节。通过这些相互作用，GPCR发挥了 在细胞脂质信号传导和生物体脂质稳态中的基本作用。理解的关键障碍 GPCR如何调节人体代谢的关键是缺乏研究细胞中脂质的工具。我发明了一种独特的 技能和一套工具来可视化，量化和操纵初级纤毛的脂质，以应对这些挑战。 该提案测试了与纤毛脂质信号相关的三个基本问题。首先，尽管 虽然初级纤毛膜在调节代谢中具有重要作用，但尚不清楚初级纤毛膜是否因饮食而改变。 脂质。外部刺激强烈地改变质膜（PM）组成以驱动细胞信号事件 维持细胞内稳态所必需的为了在纤毛上测试这一点，我将用脂肪酸或胆固醇处理细胞， 人类的饮食，并询问膜组成是否改变。将在小鼠中进一步检查纤毛脂质 喂养不同的食物饮食和患有代谢疾病的小鼠（目的1）。其次，尽管有一个膜， 初级纤毛在结构上与PM连续，维持着至关重要的独特膜组成 GPCR信号通过未知的机制。我将测试PM和纤毛之间是否有脂质交换 膜，然后确定脂质如何通过破坏膜运输途径传递到纤毛 (Aim 2）的情况。最后，我将确定在纤毛FFAR 4活性所需的脂质。FFAR 4是GPCR， 密切依赖于纤毛膜环境的完整性来进行信号传导。通过交叉对比这个屏幕 通过我以前进行的寻找纤毛GPCR SMO调节因子的筛选，我将确定可推广的 控制睫状体脂质稳态的途径。重要的是，这种筛选还将确定特定的脂质 FFAR 4的需求，由于其在胰岛素中的作用，FFAR 4是治疗代谢疾病的有希望的靶标 分泌和脂肪生成。通过这项研究，我将开发出强大的方法，可用于 在不同的背景下研究纤毛，我将推进我们对纤毛生物学，膜生物学， GPCR信号传导。该项目的长期愿景是确定纠正脂质或GPCR的新策略 在人类代谢疾病中发现的信号缺陷。