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 原发性纤毛是一种细胞表面细胞器，在人类健康中起关键作用。多个G蛋白偶联 受体（GPCR）被贩运到原发性纤毛，在那里它们携带细胞外信号 启动细胞内信号事件的膜。遗传研究已将纤毛原发性的GPCR信号连接起来 人类代谢疾病。例如，睫状GPCR调节多种代谢过程，例如 对饱腹感的感知，胰岛素的分泌以及脂肪细胞的形成。 42％的美国成年人分类 肥胖，了解主要纤毛作为GPCR信号中心的功能对于解决问题至关重要 这个主要的人类健康问题。在此提案中，我将测试主要的纤毛膜组成 控制GPCR信号。通过（1）直接结合和（2），脂质对GPCR信号具有深远的影响 通过改变膜双层特性，间接调制。通过这些互动，GPCR播放 在细胞脂质信号传导和有机脂质稳态中的基本作用。理解的关键障碍 GPCR如何调节人类代谢是缺乏研究细胞中脂质的工具。我已经开发了一个独特的 技能和一组工具可以在主要纤毛中可视化，量化和操纵脂质以应对这些挑战。 该提案测试了与纤毛脂质信号有关的三个基本问题。首先，尽管有它 在调节代谢方面的重要性，尚不清楚纤毛膜是否因饮食而改变 脂质。外部刺激可牢固地改变质膜（PM）组成以驱动细胞信号事件 细胞稳态所必需的。为了在纤毛中进行测试，我将用脂肪酸或胆固醇对细胞进行模仿 人类饮食并询问膜成分是否改变。小鼠将进一步检查纤毛脂质 在具有代谢性疾病的小鼠中喂养不同的食物饮食（AIM 1）。第二，尽管有膜 在结构上与PM连续，主要纤毛保持着独特的膜组成，至关重要 用于通过未知机制的GPCR信号传导。我将测试脂质是否在PM和Cilia之间交换 膜，然后确定如何通过破坏膜运输途径将脂质传递到纤毛 （目标2）。最后，我将确定纤毛中FFAR4活性需要哪些脂质。 FFAR4是GPCR 密切依赖纤毛膜环境的完整性来信号传导。通过交叉比较此屏幕 我先前执行的屏幕以查找纤毛GPCR SMO的调节剂，我将确定可概括的 控制睫状脂质稳态的途径。重要的是，此屏幕还将确定特定的脂质 FFAR4的要求，这是治疗代谢疾病的有希望的靶标，由于其在胰岛素中的作用 分泌和成生成。通过这项研究，我将开发可用于 在各种情况下研究纤毛，我将提高我们对纤毛生物学，膜生物学和 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 人类代谢疾病中发现的信号缺陷。