The role of PTP1B in leptin receptor-dependent and -independent regulation of ene

PTP1B 在瘦素受体依赖性和非依赖性 ene 调节中的作用

• 批准号: 8411139
• 负责人: Ryan Tsou
• 金额: $ 3.19万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-03-01 至 2014-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8411139
• 关键词: Adipocytes; Adipose tissue; Adult; Affect; Basic Science; Biological Assay; Body Weight; Brain; Cells; Chronic; Cultured Cells; Cytokine Signaling; Diet; Disease; Dose; Eating; Endocrine; Energy Metabolism; Enzymes; Epidemic; Evaluation; Fatty acid glycerol esters; Feedback; Fellowship; Food Energy; Genes; Genetic; Goals; Health; Homeostasis; Hormones; Hypothalamic structure; In Vitro; Individual; Injection of therapeutic agent; Interleukin-6; Janus kinase 2; Knock-out; Knockout Mice; Leptin; Leptin resistance; Light; Measures; Mediating; Metabolic; Metabolic Diseases; Metabolism; Molecular Biology Techniques; Mus; Mutation; Non-Insulin-Dependent Diabetes Mellitus; Obesity; Pathogenesis; Pathway interactions; Peripheral; Phenotype; Phosphoric Monoester Hydrolases; Physiology; Play; Population; Protein Tyrosine Kinase; Public Health; Rattus; Recombinant Interleukins; Regulation; Research; Research Design; Resistance; Risk; Role; Signal Pathway; Signal Transduction; Synapsins; Testing; Tissues; Training; United States; Viral; Work; base; cytokine; diabetic; energy balance; glucose tolerance; human PTPRT protein; in vitro Model; in vivo; insulin tolerance; knock-down; leptin receptor; mRNA Expression; mouse model; mutant; novel; protein tyrosine phosphatase 1B; public health relevance; small hairpin RNA

DESCRIPTION (provided by applicant): Obesity is a major health concern in the United States and abroad. Recent estimates within the US classify more than 30% of the adult population as obese (BMI > 30). Since obesity increases the health risks for other associated metabolic and non-metabolic disorders, the increasing obesity epidemic is a major concern for public health. The brain functions as an organized and integrative center in the control of body weight, regulating both food intake and energy expenditure. Leptin is a hormone secreted from the peripheral adipose tissue that acts primarily in the brain to suppress food intake and increase energy expenditure. Mice with a mutation in the gene encoding leptin (ob/ob) are obese and diabetic. Protein tyrosine phosphatase 1B (PTP1B) has been shown to negatively regulate leptin signaling, and whole body and brain-specific PTP1B -/- mice are resistant to diet-induced obesity and are leptin hyper-sensitive. Interestingly, leptin and PTP1B double knockouts (PTP1B-/- ob/ob) mice are leaner than ob/ob single knockouts, suggesting that PTP1B may regulate additional non-leptin signaling pathways which regulate body weight and metabolism. Thus, whether PTP1B requires intact leptin signaling for its metabolic effects remains unclear. Other non-leptin circulating factors have been implicated in the control of energy homeostasis. Interleukin-6 (IL-6) is a circulating cytokine that, like leptin, is found at levels which correlate with adipose mass. Central injection of low dose IL-6 was shown to increase energy expenditure in rats, and chronic daily injections of IL-6 suppressed body weight. IL- 6 has been shown to signal through an intracellular pathway similar to that of leptin. This pathway involves downstream activity by Janus kinase 2 (JAK2), a known substrate of PTP1B. The goal of this proposal is to train the fellowship applicant in a variety of molecular biology techniques, mouse genetics, and in vivo physiology in order to test the hypothesis that PTP1B's metabolic effects are mediated by both leptin- dependent and leptin-independent signaling. Additionally, this proposal aims to test the hypothesis that PTP1B regulates IL-6 signaling. The first aim is to determine whether PTP1B regulates energy balance through a leptin receptor-dependent or -independent manner in the CNS. This will be done with mouse genetics by generating CNS-specific leptin receptor and PTP1B double mutants and comparing their metabolic phenotypes with those of single mutants and wild type controls. The second aim is to determine whether PTP1B regulates IL-6 signaling involved in the central control of metabolism. PTP1B expression will be knocked down in cultured cells via viral-mediated shRNA, and activation of downstream effectors of IL-6 (pJAK, pSTAT) will be measured. Additionally, IL-6 sensitivity in vivo will be assessed based upon the in vitro results.

描述(由申请者提供)：肥胖是美国和国外的一个主要健康问题。美国国内最近的估计显示，超过30%的成年人口属于肥胖(BMI&GT；30)。由于肥胖增加了其他相关代谢性和非代谢性疾病的健康风险，日益增长的肥胖症流行是公众健康的主要关切。大脑在控制体重方面发挥着有组织和综合的中心作用，调节食物摄入量和能量消耗。瘦素是一种由外周脂肪组织分泌的激素，主要作用于大脑，以抑制食物摄入和增加能量消耗。编码瘦素(ob/ob)基因突变的小鼠是肥胖和糖尿病的。蛋白酪氨酸磷酸酶1B(PTP1B)对瘦素信号具有负性调节作用，PTP1B-/-小鼠对饮食诱导的肥胖具有抵抗力，对瘦素高度敏感。有趣的是，瘦素和PTP1B双基因敲除(PTP1B-/-ob/ob)小鼠比ob/ob单基因敲除小鼠更瘦，这表明PTP1B可能调节额外的非瘦素信号通路，调节体重和代谢。因此，PTP1B是否需要完整的瘦素信号来实现其代谢作用仍不清楚。其他非瘦素循环因子也参与了能量平衡的控制。白介素6(IL-6)是一种循环细胞因子，与瘦素一样，存在于与脂肪质量相关的水平。中枢注射低剂量IL-6可增加大鼠的能量消耗，而每日长期注射IL-6则抑制体重。已有研究表明，IL-6通过与瘦素类似的细胞内途径发出信号。这一途径涉及已知的PTP1B底物Janus kinase2(JAK2)的下游活性。这项建议的目的是在各种分子生物学技术、小鼠遗传学和体内生理学方面对奖学金申请者进行培训，以检验PTP1B的代谢效应是由瘦素依赖和非瘦素非依赖信号介导的假设。此外，这项建议旨在检验PTP1B调节IL-6信号的假设。第一个目的是确定PTP1B是否通过瘦素受体依赖或非依赖的方式调节中枢神经系统的能量平衡。这将通过产生中枢神经系统特异性瘦素受体和PTP1B双突变，并将它们的代谢表型与单一突变和野生型对照进行比较，用小鼠遗传学来完成。第二个目的是确定PTP1B是否调节参与新陈代谢中枢控制的IL-6信号。通过病毒介导的shRNA下调PTP1B在培养细胞中的表达，并检测IL-6下游效应因子(PJAK，pSTAT)的激活。此外，IL-6在体内的敏感性将根据体外结果进行评估。