Competing effects of AgRP and POMC neurons on cAMP signaling in downstream neurons in vivo

AgRP 和 POMC 神经元对体内下游神经元 cAMP 信号传导的竞争作用

基本信息

批准号：
10572109
负责人：
Xingjie Zhang
金额：
$ 9.15万
依托单位：
BETH ISRAEL DEACONESS MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-02-01 至 2025-01-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10572109
关键词：
Adenylate Cyclase Adult Affect Animals Axon Behavior Biochemical Biochemical Process Body Weight Brain Cell Compartmentation Cells Cilia Concentration Camps Cyclic AMP Data Dendrites Drug Delivery Systems Eating Electrophysiology (science)Energy Metabolism Engineering Fasting Feeding behaviors Felis catus Genetic study Goals Grant Histology Human Hunger Hypothalamic structure Image Individual Influentials Intraventricular Knowledge Learning Light Measurement Measures Mentors Modeling Molecular Monitor Morbid Obesity Mus Mutation Nature Neurons Neuropeptides Obesity Obesity Epidemic Optics PDE4D3 Partner in relationship Pathway interactions Peptide Receptor Peptide Signal Sequences Peptides Pharmacologic Substance Physiology Production Protein Engineering Research Research Personnel Satiation Second Messenger Systems Signal Transduction Slice Synapses Synaptic plasticity Techniques Technology Testing Time Titrations Training Viral career development design energy balance experimental study feeding fluorescence lifetime imaging in vivo in vivo imaging insight meetings neuronal cell body novel obesity treatment optical sensor optogenetics paraventricular nucleus patch clamp phosphoric diester hydrolase prevent programs real time monitoring receptor receptor function sensor skills subcellular targeting tool two-photon

项目摘要

PROJECT SUMMARY Hypothalamic AgRP hunger neurons and POMC satiety neurons use neuropeptides AgRP, NPY, and αMSH to regulate food intake, energy expenditure, and body weight. One important downstream target is the satiety- promoting MC4R receptor-expressing neurons in the paraventricular nucleus of the hypothalamus (PVHMC4R), which receive converging peptidergic signals from AgRP and POMC neurons. However, exactly how PVHMC4R neurons interpret and integrate these peptide signals remains unclear, especially regarding the involvement of the downstream second messenger cAMP. The central unknowns can be summarized into three questions: (i) How do hunger and satiety peptides alter cAMP in PVHMC4R neurons? (ii) How does cAMP regulate the spiking of PVHMC4R neurons? (iii) Where in a PVHMC4R neuron is cAMP signaling most influential in regulating PVHMC4R activity? The main barrier to answering these questions is the lack of tools to measure and manipulate cAMP in PVHMC4R neurons. I have recently overcome this barrier by helping develop and apply a molecular and optical toolset to measure, make, and degrade cAMP during behaviors. The studies and career development activity in this K99/R00 proposal are designed to provide me with the necessary training to initiate an independent research program that applies the new cAMP tools to understand peptide signaling in PVHMC4R neurons. I hypothesize that coordinated, opposing changes in AgRP and POMC neuron activity regulate spiking in PVHMC4R neurons via competing actions on cAMP signaling. To test this hypothesis, I propose the following aims: Aim 1: To image cAMP dynamics in PVHMC4R neurons with the optical sensor cADDis during experimentally induced and feeding-induced peptide release, and to compare cAMP signaling between fasted and fed states. Aim 2: To measure how directly increasing cAMP (using a new optogenetic tool, biPAC) and degrading cAMP (using an engineered phosphodiesterase, PDE4D3-Cat) changes plasticity and spiking of PVHMC4R neurons. Aim 3: To engineer and use subcellularly targeted cADDis, biPAC, PDE4D3-Cat in order to understand local cAMP signaling in PVHMC4R neurons. The proposed research will be mentored by Drs. Mark Andermann and Bradford Lowell, who will also provide guidance on becoming an independent researcher. I will learn new techniques in intraventricular drug delivery, whole-cell patch-clamp, and measurements of energy expenditure from my mentors as well as Drs. Alex Banks, Maria Lehtinen, and Joseph Majzoub. I will receive training in protein engineering from Drs. Shiqiang Gao, Georg Nagel, Bernardo Sabatini, and Gary Yellen. I will acquire new skills from the above experts and from courses and scientific meetings, combined with my existing expertise in cAMP research. This will enable me to understand when, where, and how cAMP is used to titrate PVHMC4R neurons activity. These results will fill an important knowledge gap in developing and understanding treatments for obesity.

项目概要下丘脑 AgRP 饥饿神经元和 POMC 饱足神经元使用神经肽 AgRP、NPY 和 αMSH 调节食物摄入量、能量消耗和体重。一个重要的下游目标是饱腹感。促进下丘脑室旁核（PVHMC4R）中表达 MC4R 受体的神经元，然而，PVHMC4R 究竟如何接收来自 AgRP 和 POMC 神经元的汇聚肽能信号。神经元解释和整合这些肽信号仍不清楚，特别是关于下游第二信使 cAMP 的中心未知数可归纳为三个问题： (i) 饥饿和饱足肽如何改变 PVHMC4R 神经元中的 cAMP？ (ii) cAMP 如何调节 PVHMC4R 神经元的尖峰？ (iii) PVHMC4R 神经元中 cAMP 信号传导对调节 PVHMC4R 活性影响最大的位置是哪里？回答这些问题的主要障碍是缺乏测量和操作 PVHMC4R 中 cAMP 的工具我最近通过帮助开发和应用分子和光学工具集克服了这一障碍。在行为过程中测量、制造和降解 cAMP。 K99/R00 提案旨在为我提供启动独立研究所需的培训程序应用新的 cAMP 工具来了解 PVHMC4R 神经元中的肽信号传导。 AgRP 和 POMC 神经元活动的协调、相反的变化调节 PVHMC4R 神经元的尖峰为了检验这一假设，我提出以下目标：目标 1：在实验过程中使用光学传感器 cADDis 对 PVHMC4R 神经元中的 cAMP 动态进行成像诱导和进食诱导的肽释放，并比较禁食和进食状态之间的 cAMP 信号传导。目标 2：测量如何直接增加 cAMP（使用新的光遗传学工具 biPAC）和降解 cAMP （使用工程磷酸二酯酶 PDE4D3-Cat）改变 PVHMC4R 神经元的可塑性和尖峰。目标 3：设计和使用亚细胞靶向 cADDis、biPAC、PDE4D3-Cat 以了解局部 PVHMC4R 神经元中的 cAMP 信号传导。拟议的研究将由马克·安德曼博士和布拉德福德·洛厄尔博士指导，他们也将提供成为一名独立研究员的指导我将学习心室内药物输送的新技术，全细胞膜片钳，以及我的导师和亚历克斯·班克斯博士的能量消耗测量，我将接受 Maria Lehtinen 和 Joseph Majzoub 博士的蛋白质工程培训。内格尔、贝尔纳多·萨巴蒂尼和加里·耶伦我将从上述专家和课程中获得新技能。和科学会议，结合我在 cAMP 研究方面的现有专业知识，这将使我能够了解何时、何地以及如何使用 cAMP 来滴定 PVHMC4R 神经元活动。这些结果将填补一个空白。在开发和理解肥胖治疗方面存在重要的知识差距。