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: 8126940
• 负责人: Ryan Tsou
• 金额: $ 4.18万
• 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/8126940
• 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; 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. PUBLIC HEALTH RELEVANCE: The proposed work is basic research designed to elucidate the role of protein tyrosine phosphatase 1B (PTP1B) in the central control of energy homeostasis. Understanding the function and pathways of PTP1B in the brain may shed light on new targets and novel pathways for treating metabolic disorders such as obesity and type 2 diabetes.

描述（由申请人提供）：肥胖是美国和国外的一个主要健康问题。美国最近的估计将超过 30% 的成年人口归类为肥胖（BMI > 30）。由于肥胖会增加其他相关代谢和非代谢疾病的健康风险，因此日益严重的肥胖流行病是公众健康的一个主要问题。大脑作为控制体重、调节食物摄入和能量消耗的有组织的综合中心发挥作用。瘦素是一种从周围脂肪组织分泌的激素，主要在大脑中发挥作用，抑制食物摄入并增加能量消耗。瘦素编码基因 (ob/ob) 发生突变的小鼠患有肥胖症和糖尿病。蛋白酪氨酸磷酸酶 1B (PTP1B) 已被证明可以负向调节瘦素信号传导，全身和大脑特异性 PTP1B -/- 小鼠对饮食诱导的肥胖具有抵抗力，并且对瘦素高度敏感。有趣的是，瘦素和 PTP1B 双敲除 (PTP1B-/- ob/ob) 小鼠比 ob/ob 单敲除小鼠更瘦，这表明 PTP1B 可能调节额外的非瘦素信号通路，从而调节体重和新陈代谢。因此，PTP1B 是否需要完整的瘦素信号传导来发挥其代谢作用仍不清楚。其他非瘦素循环因素与能量稳态的控制有关。白介素 6 (IL-6) 是一种循环细胞因子，与瘦素一样，其水平与脂肪量相关。中枢注射低剂量 IL-6 会增加大鼠的能量消耗，并且每天长期注射 IL-6 会抑制体重。 IL-6 已被证明通过类似于瘦素的细胞内途径发出信号。该途径涉及 Janus 激酶 2 (JAK2) 的下游活性，Janus 激酶 2 是 PTP1B 的已知底物。该提案的目标是对奖学金申请者进行各种分子生物学技术、小鼠遗传学和体内生理学方面的培训，以检验 PTP1B 的代谢作用是由瘦素依赖性和瘦素非依赖性信号传导介导的假设。此外，该提案旨在检验 PTP1B 调节 IL-6 信号传导的假设。第一个目标是确定 PTP1B 是否通过中枢神经系统中瘦素受体依赖或独立的方式调节能量平衡。这将通过小鼠遗传学来完成，方法是生成 CNS 特异性瘦素受体和 PTP1B 双突变体，并将它们的代谢表型与单突变体和野生型对照的代谢表型进行比较。第二个目的是确定 PTP1B 是否调节参与代谢中枢控制的 IL-6 信号传导。 PTP1B 表达将通过病毒介导的 shRNA 在培养细胞中被敲低，并测量 IL-6 下游效应器（pJAK、pSTAT）的激活。此外，将根据体外结果评估体内 IL-6 敏感性。 公共健康相关性：拟议的工作是基础研究，旨在阐明蛋白酪氨酸磷酸酶 1B (PTP1B) 在能量稳态中央控制中的作用。了解 PTP1B 在大脑中的功能和通路可能有助于找到治疗肥胖和 2 型糖尿病等代谢性疾病的新靶点和新通路。