Maternal Obesity affects AMP-Kinase in Muscle Cell Differentiation

母亲肥胖影响肌细胞分化中的 AMP 激酶

• 批准号: 8306744
• 负责人: MIN DU
• 金额: $ 23.82万
• 依托单位: WASHINGTON STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-27 至 2015-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8306744
• 关键词: 5' -AMP-activated protein kinase; Acetylesterase; Activities of Daily Living; Adipocytes; Adult; Affect; Affinity; Aging; American; Antidiabetic Drugs; Attenuated; Barker Hypothesis; Birth; Catalytic Domain; Cell Differentiation process; Cells; Child; Country; Cultured Cells; Data; Development; Developmental Biology; Diabetes Mellitus; Diet; Down-Regulation; EP300 gene; Embryo; Energy Metabolism; Ensure; Environment; Epidemic; Event; Fatty acid glycerol esters; Fetal Development; Fetus; Fibroblasts; Fibrosis; Gene Expression; Glucose; Health; Histones; Impairment; Incidence; Insulin; Insulin Resistance; Intervention; Intramuscular; Knockout Mice; Knowledge; Laboratories; Life; Link; Location; Mediating; Mediator of activation protein; Mesenchymal; Mesenchymal Stem Cells; Messenger RNA; Metabolic; Metabolism; Metformin; Methodology; Molecular; Mus; Muscle; Muscle Cells; Muscle Development; Muscle Fibers; Muscle function; Neonatal; Non-Insulin-Dependent Diabetes Mellitus; Nuclear Receptors; Obese Mice; Obesity; Pathway interactions; Peripheral; Peroxisome Proliferator-Activated Receptors; Pharmaceutical Preparations; Phosphorylation; Physiological; Pregnant Women; Protein Isoforms; Proteins; Regulation; Role; Signal Pathway; Signal Transduction; Skeletal Muscle; Staging; Staining method; Stains; Stress; Teenagers; Testing; Tissues; Transforming Growth Factors; United States; Universities; Woman; Work; Wyoming; adenylate kinase; animal facility; attenuation; child bearing; clinical application; density; experience; fatty acid oxidation; fetal; fetal programming; fibrogenesis; glucose uptake; in vivo; laboratory facility; lipid biosynthesis; mouse model; muscle form; muscle strength; myogenesis; novel; offspring; paracrine; pregnant; prevent; public health relevance; stem cell differentiation; transcription factor

DESCRIPTION (provided by applicant): SIGNIFICANCE: 18-35% of pregnant American women are clinically obese, a condition which affects fetal development with long-term consequences for offspring health, including pre-disposition to obesity and type 2 diabetes (T2D). The underlying mechanisms remain poorly defined. RATIONALE: Skeletal muscle (SM) is a key tissue responsive to the oxidation of fatty acids and glucose, and its transition to insulin resistance (IR) precedes the onset of T2D. The fetal stage is crucial for SM development since there is no net increase in the number of SM fibers after birth. Our preliminary studies in fetal SM indicate that maternal obesity (MO) reduced AMP-activated protein kinase (AMPK) activity, and altered fetal SM development by enhancing intramuscular adipogenesis and fibrogenesis, both of which impair SM functions. Myocytes, adipocytes and fibroblasts in fetal SM are derived from mesenchymal stem cells (MSC). Our preliminary studies show that AMPK phosphorylates and enhances 2-catenin mediated signaling, a pathway promoting myogenesis. AMPK also phosphorylates p300, which is expected to impair its function as a co-activator, and p300 is a necessary co-activator for transcription factors regulating adipogenesis and fibrogenesis. AMPK catalytic subunit has two isoforms demonstrating slightly different roles in metabolism. CENTRAL HYPOTHESIS: MO inhibits AMPK, which reduces phosphorylation of 2-catenin and p300 by AMPK, leads to the down-regulation of 2-catenin but enhancement of p300 mediated signaling and a shift from myogenesis to adipogenesis/fibrogenesis during fetal SM development. We have three SPECIFIC AIMS: 1) Evaluate whether 2-catenin is the key mediator linking AMPK to myogenesis in fetal SM; 2) Examine the link between p300 phosphorylation by AMPK and adipogenesis/fibrogenesis in fetal SM; 3) Assess the isoform specific effect of AMPK on myogenesis, adipogenesis and fibrogenesis. APPROACH: We plan to use mouse mesenchymal C3H10T1/2 cells to assess whether p300 and 2-catenin are key mediators between AMPK and MSC differentiation in fetal SM. We will also use the well-established diet-induced obesity mouse model to induce MO and the available AMPK-isoform-specific knockout mice to evaluate the role of AMPK in fetal SM development. Important mediators of selected signaling pathways will be analyzed at both mRNA and protein levels, as well as their location by immunohistochemical staining in fetal SM. OBJECTIVE: The objective is to test the role of AMPK in fetal SM development due to MO and to further explore mechanisms. INNOVATION: We are pioneering studies to define the role of AMPK in fetal SM development. The proposed work is novel, because the effects of AMPK and its associated signaling pathways on fetal SM development due to MO are just becoming to be appreciated. ENVIRONMENT: All methodologies required are already established in our laboratory. The Developmental Biology Group and the Center for the Study of Fetal Programming provide excellent academic environment, and animal and laboratory facilities. IMPACT: Proposed studies will demonstrate AMPK as a key mediator of fetal SM development, which will make it possible to use numerous available anti- diabetic drugs, known activators of AMPK, to prevent impairment of fetal SM development due to MO. Data and knowledge obtained will also allow us to further explore mechanisms regulating fetal SM development due to other maternal physiological stresses. Given the importance of SM for lifelong activities and its close association with obesity and T2D, such intervention will help the increasing number of obese pregnant women in this country to deliver healthy children. PUBLIC HEALTH RELEVANCE: The United States is experiencing an obesity epidemic which increasingly involves women of child bearing years. 18-35% of pregnant American women are clinically obese, a condition which affects fetal development with long-term consequences for offspring health, including pre-disposition to obesity and Type 2 diabetes. The underlying mechanisms are poorly defined. The objectives of proposed studies are to explore mechanisms associated with impairment of fetal skeletal muscle development due to maternal obesity. Knowledge obtained will allow us to further explore fetal skeletal muscle development due to maternal obesity and other maternal physiological stresses. Molecular mediators identified are targets for interventions to ensure proper skeletal muscle development in fetuses of obese women. Due to the importance of skeletal muscle for lifelong activities and its close association with obesity and Type 2 diabetes, such intervention will help the increasing number of obese pregnant women in this country to deliver healthy children.

描述（由申请人提供）： 意义：18-35% 的美国孕妇患有临床肥胖症，这种情况会影响胎儿发育，对后代健康产生长期影响，包括易患肥胖症和 2 型糖尿病 (T2D)。根本机制仍然不明确。基本原理：骨骼肌 (SM) 是对脂肪酸和葡萄糖氧化做出反应的关键组织，其向胰岛素抵抗 (IR) 的转变先于 T2D 的发作。胎儿阶段对于 SM 发育至关重要，因为出生后 SM 纤维的数量不会净增加。我们对胎儿 SM 的初步研究表明，母亲肥胖 (MO) 会降低 AMP 激活蛋白激酶 (AMPK) 活性，并通过增强肌内脂肪生成和纤维生成来改变胎儿 SM 发育，这两者都会损害 SM 功能。胎儿 SM 中的肌细胞、脂肪细胞和成纤维细胞均源自间充质干细胞 (MSC)。我们的初步研究表明，AMPK 磷酸化并增强 2-连环蛋白介导的信号传导，这是一种促进肌生成的途径。 AMPK 还会磷酸化 p300，这预计会损害其作为共激活剂的功能，而 p300 是调节脂肪生成和纤维发生的转录因子必需的共激活剂。 AMPK 催化亚基有两种亚型，在代谢中的作用略有不同。中心假设：MO 抑制 AMPK，从而减少 AMPK 对 2-连环蛋白和 p300 的磷酸化，导致 2-连环蛋白下调，但增强 p300 介导的信号传导，并在胎儿 SM 发育过程中从肌生成转变为脂肪生成/纤维生成。我们有三个具体目标：1) 评估 2-catenin 是否是连接 AMPK 与胎儿 SM 肌生成的关键介质； 2) 检查 AMPK 磷酸化 p300 与胎儿 SM 中脂肪生成/纤维生成之间的联系； 3) 评估 AMPK 对肌生成、脂肪生成和纤维生成的亚型特异性作用。方法：我们计划使用小鼠间充质 C3H10T1/2 细胞来评估 p300 和 2-catenin 是否是胎儿 SM 中 AMPK 和 MSC 分化之间的关键介质。我们还将使用成熟的饮食诱导肥胖小鼠模型来诱导 MO，并使用现有的 AMPK 异构体特异性敲除小鼠来评估 AMPK 在胎儿 SM 发育中的作用。将在 mRNA 和蛋白质水平上分析选定信号通路的重要介质，并通过胎儿 SM 中的免疫组织化学染色来分析它们的位置。目的：检测 AMPK 在 MO 引起的胎儿 SM 发育中的作用并进一步探讨机制。创新：我们正在进行开创性研究，以确定 AMPK 在胎儿 SM 发育中的作用。这项工作是新颖的，因为 AMPK 及其相关信号通路对 MO 引起的胎儿 SM 发育的影响刚刚开始被人们所认识。环境：我们的实验室已经建立了所需的所有方法。发育生物学组和胎儿编程研究中心提供优良的学术环境以及动物和实验室设施。影响：拟议的研究将证明 AMPK 是胎儿 SM 发育的关键介质，这将使使用多种可用的抗糖尿病药物（已知的 AMPK 激活剂）来预防 MO 引起的胎儿 SM 发育受损成为可能。获得的数据和知识也将使我们能够进一步探索由于其他母体生理压力而调节胎儿 SM 发育的机制。鉴于 SM 对终生活动的重要性及其与肥胖和 T2D 的密切关系，此类干预将帮助该国越来越多的肥胖孕妇生出健康的孩子。 公共卫生相关性：美国正在经历肥胖流行病，其中越来越多的育龄妇女受到影响。 18-35% 的美国孕妇患有临床肥胖症，这种情况会影响胎儿发育，对后代健康产生长期影响，包括易患肥胖症和 2 型糖尿病。底层机制的定义不明确。拟议研究的目的是探索与母亲肥胖导致胎儿骨骼肌发育受损相关的机制。获得的知识将使我们能够进一步探索由于母亲肥胖和其他母亲生理压力而导致的胎儿骨骼肌发育。确定的分子介质是干预措施的目标，以确保肥胖妇女胎儿的骨骼肌正常发育。由于骨骼肌对于终生活动的重要性及其与肥胖和 2 型糖尿病的密切关系，此类干预措施将帮助该国越来越多的肥胖孕妇生出健康的孩子。