Human adipose tissue in control of sympathetic tone and metabolic rate

人类脂肪组织控制交感神经张力和代谢率

基本信息

批准号：
10749552
负责人：
Silvia Corvera
金额：
$ 72.54万
依托单位：
UNIV OF MASSACHUSETTS MED SCH WORCESTER
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：
2023-09-01 至 2027-08-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10749552
关键词：
Acceleration Adipocytes Adipose tissue Adrenergic Agents Adrenergic Receptor Affect Antidepressive Agents Basal metabolic rate Biological Availability Blood Glucose Blood Vessels Body Temperature Body Weight decreased Brain CRISPR/Cas technology Calories Cells Closure by clamp Communication Cues Dependence Development Enzymes Experimental Models Exposure to Fasting Fatty Acids Fatty acid glycerol esters Forms Controls Genes Grant Health Heart Heart Diseases Homeostasis Hormone secretion Human Human body Hybrids Hyperglycemia Immunocompromised Host Implant Knock-out Lipolysis Liver Measures Mediating Mesenchymal Stem Cells Metabolic Metabolic Diseases Metabolism Methodology Modeling Monoamine Oxidase A Mus Muscle NRIP1 gene Nerve Neurons Neurotransmitters Non-Insulin-Dependent Diabetes Mellitus Norepinephrine Obesity Organ Organ Temperatures Physiological Play Positioning Attribute Predisposition Probability Proteins Recycling Respiration Role Signal Transduction Site Stimulus Techniques Technology Testing Therapeutic Thermogenesis Tissues Vascularization Weight Gain Work blood glucose regulation comparison control design disorder risk fatty liver disease glucose disposal glucose metabolism implantation improved in vivo insulin sensitivity knock-down metabolic rate monoamine nanoparticle nerve supply novel novel strategies novel therapeutics overexpression pharmacologic response stem cells subcutaneous virtual

项目摘要

ABSTRACT Sympathetic outflow to adipose tissue regulates whole body energy homeostasis by stimulating lipolysis in white adipocytes and thermogenesis in brown or beige adipocytes. Using a novel approach to study human adipose tissue in mice [1, 2], we have found that, during development, human adipocytes express a high level of monoamine oxidase A (MAOA), a major mechanism for degradation of norepinephrine, and a known target of antidepressant drugs [3]. Notably, expression of Maoa is virtually undetectable in mouse adipocytes, indicating that this control mechanism may have evolved to meet the metabolic features of larger species. We find that human adipocyte MAOA is decreased during beige adipose tissue development, potentially increasing norepinephrine bioavailability, adrenergic tone and thermogenic capacity. Thus, MAOA expression in human adipocytes is a previously underappreciated, key mechanism controlling adipose tissue functions, potentially underlying susceptibility to obesity and metabolic disease. In this proposal, we will further test the hypothesis that adipocyte MAOA controls systemic energy homeostasis through its effects on adipose tissue sympathetic responsiveness. We have developed methodologies to obtain large numbers of human multipotent mesenchymal progenitor cells that can differentiate into multiple adipocyte subtypes, and can generate functional adipose tissue upon implantation in vivo. We have also successfully deleted MAOA from these cells using a novel nanoparticle-based, CRISPR-Cas9 protein delivery technique, resulting in a >90% depletion of MAOA protein while avoiding non-specific effects of expressed Cas9. Leveraging these technologies, we shall: Aim 1. Test the hypothesis that human adipocyte MAOA limits lipolytic and thermogenic responses to norepinephrine. We will measure lipolysis and induction of thermogenesis in control and MAOA-deleted human adipocytes exposed to norepinephrine, as well as steady-state norepinephrine levels and dependency on the monoamine transporter Oct3. Aim 2. We will test the hypothesis that MAOA in human adipocytes regulates the development and responsiveness of thermogenic adipose tissue in vivo. We will measure the rate and extent of vascularization and innervation, and thermogenic responsiveness to environmental stimuli of tissue developed in NSG mice from control or MAOA deleted human adipocytes. Aim 3. We will test the hypothesis that expression of MAOA in adipocytes will determine susceptibility to obesity, systemic insulin sensitivity and systemic glucose homeostasis. We will analyze weight gain, adipocyte size, insulin sensitivity, glucose disposal under hyper insulinemic, hyperglycemic clamps, and basal metabolic rate in mice harboring adipose depots formed from control or MAOA deleted human adipocytes, and in mice overexpressing MaoA in subcutaneous adipose tissue. These aims will provide the basis for further development of tissue specific MAOA-targeting strategies as novel therapeutics for metabolic disease.

抽象的交感神经流向脂肪组织通过刺激脂肪分解来调节全身能量稳态白色脂肪细胞和棕色或米色脂肪细胞的产热作用。使用新颖的方法来研究人类通过对小鼠脂肪组织的研究 [1, 2]，我们发现，在发育过程中，人类脂肪细胞表达高水平单胺氧化酶 A (MAOA) 是去甲肾上腺素降解的主要机制，也是一种已知的抗抑郁药物的作用靶点[3]。值得注意的是，Maoa 的表达在小鼠脂肪细胞中几乎检测不到，表明这种控制机制可能已经进化以满足较大物种的代谢特征。我们发现人类脂肪细胞 MAOA 在米色脂肪组织发育过程中减少，可能增加去甲肾上腺素生物利用度、肾上腺素能张力和产热能力。因此，MAOA在人类中的表达脂肪细胞是一种以前未被充分认识的控制脂肪组织功能的关键机制，对肥胖和代谢疾病的潜在易感性。在这个提案中，我们将进一步测试脂肪细胞 MAOA 通过其对脂肪组织的影响来控制全身能量稳态的假设同情反应。我们开发了获得大量人类多能细胞的方法间充质祖细胞可分化为多种脂肪细胞亚型，并可产生植入体内后的功能性脂肪组织。我们还成功地从这些细胞中删除了 MAOA 使用基于纳米颗粒的新型 CRISPR-Cas9 蛋白质递送技术，导致 90% 以上的 MAOA 蛋白，同时避免表达的 Cas9 的非特异性效应。利用这些技术，我们应：目标 1. 检验人类脂肪细胞 MAOA 限制脂肪分解和生热反应的假设去甲肾上腺素。我们将测量对照和 MAOA 缺失的脂肪分解和产热诱导暴露于去甲肾上腺素的人类脂肪细胞，以及稳态去甲肾上腺素水平和依赖性单胺转运蛋白 Oct3。目标 2. 我们将检验人类脂肪细胞中 MAOA 的假设调节体内产热脂肪组织的发育和反应性。我们将测量血管化和神经支配的速率和程度，以及对环境刺激的产热反应 NSG 小鼠中从对照或 MAOA 缺失的人类脂肪细胞中发育出的组织。目标 3. 我们将测试假设脂肪细胞中 MAOA 的表达将决定对肥胖、全身胰岛素的易感性敏感性和全身葡萄糖稳态。我们将分析体重增加、脂肪细胞大小、胰岛素敏感性、高胰岛素血症、高血糖钳夹和小鼠基础代谢率下的葡萄糖处理由对照或 MAOA 缺失的人类脂肪细胞形成的脂肪库，以及在过度表达 MaoA 的小鼠中皮下脂肪组织。这些目标将为组织特异性的进一步发展提供基础 MAOA 靶向策略作为代谢疾病的新型疗法。