Hormonal regulation of a Ca2+/AMPK signaling pathway

Ca2 /AMPK 信号通路的激素调节

基本信息

批准号：
8059067
负责人：
ANTHONY R MEANS
金额：
$ 15.68万
依托单位：
DUKE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-05-15 至 2011-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8059067
关键词：
Acute Adult Binding Binding Proteins Biochemical Blood Glucose Body Weight Body Weight decreased Brain Ca(2+)-Calmodulin Dependent Protein Kinase CaM kinase I activator Calcium/calmodulin-dependent protein kinase Calmodulin Catalytic Domain Cells Complex Cultured Cells Data Desire for food Diet Eating Enzyme Inhibition Enzymes Eukaryota Exhibits Family Fasting Fatty acid glycerol esters Feeding behaviors Food Gene Expression Generations Genes Glucose Grant Growth Factor Homeostasis Hormones Human Hyperglycemia Hypothalamic structure In Vitro Indirect Calorimetry Infusion procedures Knockout Mice Lead Leptin Malonyl Coenzyme A Mammalian Cell Mammals Mediating Molecular Mus NPY gene Nature Neurons Nuclear Translocation Obesity Pathway interactions Phenotype Phosphorylation Phosphotransferases Physiological Play Production Protein Isoforms Protein Kinase Protein Phosphatase 2A Regulatory Subunit PR53 Publishing RNA Regulation Relative (related person)Research Research Personnel Role Signal Pathway Signal Transduction Stress Structure of nucleus infundibularis hypothalami Structure-Activity Relationship Technology Transcriptional Activation Weight Gain Wild Type Mouse Yeasts base calmodulin-dependent protein kinase II cell type drug discovery energy balance fatty acid oxidation feeding ghrelin glucose tolerance hormone regulation insight novel novel therapeutics programs receptor response scaffold upstream kinase

项目摘要

DESCRIPTION (provided by applicant): The overall objective is to define the Ca2+-dependent signaling pathway in hypothalamic neurons that regulates appetite and body weight to provide novel insights to human obesity. AMPK, originally discovered to protect cells against stresses that deplete ATP, is a key enzyme in the pathways by which ghrelin and leptin act on arcuate nucleus (ARM) hypothalamic neurons to control production of NPY and, thus, appetite, energy homeostasis and body weight. Ca2+ is a ubiquitous 2nd messenger that mediates signaling cascades initiated by hormones and growth factors, in which calmodulin (CaM) is the Ca2+ receptor and Ca2+/CaM- dependent protein kinases (CaMK) transduce the Ca2+/CaM signal resulting in many cell responses. A "CaMK cascade" has been identified composed of Ca2+/CaM, a CaMKK (a or P) and a CaMK (I or IV). Recently the CaMKKs have also been shown to function as AMPKKs and are required to activate AMPK in some human cells. CaMKKp, a brain-specific enzyme, is expressed in the ARM and CaMKKp"'" mice show decreased hypothalamic AMPK phosphorylation/activity as well as NPY/AgRP mRNAs. Indeed, CaMKKp"'" mice share many phenotypes with mice null for NPY or an NPY receptor. Infusion of the only selective CaMKK antagonist, STO-609, into the 3rd ventricle of adult wild-type mice results in acute decreases in food intake and body weight as well as hypothalamic content of NPY/AgRP mRNAs. We hypothesize that CaMKKp serves as a primary AMPKK in NPY/AgRP neurons and that acute inhibition of this enzyme leads to decreased production of NPY which causes decreased food intake, altered energy homeostasis and weight loss. To evaluate this hypothesis we will: 1) utilize genetically altered mice to investigate the physiologically relevant role(s) of the CaMKKs, p and a as AMPKKs in mouse hypothalamus and cultured cells to clarify pathways that regulate NPY gene expression and malonyl CoA level; and 2) define the physical interaction between the CaMKKs and AMPK by employing molecular and biochemical technology to understand the nature of the CaMKK/AMPK signaling complex and how this complex can be inhibited. Our results should validate CaMKKp as a target for drug discovery, which could eventually lead to identification of new therapeutics to treat obesity.

描述（由申请人提供）：总体目标是定义下丘脑神经元中Ca2+依赖性信号传导途径，以调节食欲和体重，以提供对人肥胖的新见解。 AMPK最初被发现是为了保护细胞免受耗尽ATP的压力，是途径中的关键酶，生长素蛋白和瘦素作用于弧形核（ARM）下丘脑神经元来控制NPY的产生，从而控制NPY的产生，因此，食欲，能量，体重稳态，体重和体内体重和身体体重，。 Ca2+是无处不在的第二使者，它介导了由激素和生长因子引发的信号传导级联反应，其中钙调蛋白（CAM）是Ca2+受体和Ca2+/CAM依赖性蛋白激酶（CAMK）传递CA2+/CAM信号在许多细胞反应中导致CA2+/CAM信号。已经确定了由Ca2+/Cam，CaMkk（A或P）和CAMK（I或IV）组成的“ CAMK Cascade”。最近，CAMKK还显示出充当AMPKK，并且需要激活某些人类细胞中的AMPK。 CAMKKP是一种脑特异性酶，在手臂中表达，CAMKKP“”小鼠显示下丘脑AMPK磷酸化/活性以及NPY/AGRP mRNA。实际上，Camkkp“'”小鼠与NPY或NPY受体无效的小鼠共享许多表型。输注唯一的选择性CAMKK拮抗剂STO-609中，将成年野生型小鼠的第三个心室输注导致食物摄入和体重的急性减少以及NPY/AGRP mRNA的下丘脑含量。我们假设CAMKKP是NPY/AGRP神经元中的主要AMPKK，并且对该酶的急性抑制会导致NPY产生降低，从而导致食物摄入量减少，能量稳态改变和体重减轻。为了评估这一假设，我们将：1）利用遗传改变的小鼠研究CaMKKS，P和A AS AMPKK在小鼠下丘脑和培养的细胞中的生理相关作用，以阐明调节NPY基因表达和丙二酰基COA水平的途径； 2）通过采用分子和生化技术来了解CAMKK/AMPK信号传导复合物的性质以及如何抑制这种复合物，来定义CAMKKS和AMPK之间的物理相互作用。我们的结果应验证CAMKKP作为药物发现的靶标，这最终可能导致鉴定出新的治疗肥胖症。