SECRETION FROM ADIPOSE CELLS

脂肪细胞的分泌

• 批准号: 6363061
• 负责人: Konstantin V Kandror
• 金额: $ 21.24万
• 依托单位: BOSTON UNIVERSITY MEDICAL CAMPUS
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-03-01 至 2004-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6363061
• 关键词: Golgi apparatus; adenosinetriphosphatase; adipocytes; cell membrane; density gradient ultracentrifugation; endoplasmic reticulum; enzyme activity; enzyme inhibitors; gel electrophoresis; glucose transporter; insulin; intracellular transport; laboratory rat; leptin; lipoprotein lipase; membrane structure; microsomes; phosphatidylinositol 3 kinase; protein structure function; radiotracer; secretion; secretory protein; tissue /cell culture; transcription factor; tumor necrosis factor alpha

Fat cells produce and secret the hormone leptin, the cytokine TNF-alpha, and the enzyme lipoprotein lipase, or LPL. All these proteins play key roles in the control of nutrition, energy balance, and insulin sensitivity as well as a variety of physiological conditions which are directly or indirectly connected with these parameters. Thus, secretion of physiologically important proteins, along with triglyceride storage and insulin-sensitive glucose transport, can be considered as one of the most important functions of adipose tissue. At present, it is not known whether secretion from adipose cells is constitutive or regulated, and membrane structures, such as secretory vesicles and/or granules which represent secretory pathway(s) in these cells have not yet been identified. We propose to explore the compartmentalization of leptin, TNF-alpha, LPL, and other secreted proteins in different subcellular fractions of rat adipocytes (endoplasmic reticulum, Golgi apparatus, plasma membrane, etc.) using either classical biochemical techniques (gradient centrifugations, agarose gel electrophoresis) or immunoadsorption with specific antibodies. We also propose to identify the constitutive secretory pathway in adipocytes and to compare intracellular compartmentalization of secreted molecules to constitutive secretory vesicles on one hand and to insulin-sensitive Glut4-containing vesicles, on the other. We will study the process of adipose cell secretion with the help of various secretagogues as well as specific inhibitors of key enzymes involved in membrane traffic, such as PI 3-kinase, Arf, V-type ATPase (proton pump) and others. In the process of this work, we expect to determine whether secretion and Glut4 translocation represent different pathways of membrane trafficking in adipocytes and to get an insight into the molecular mechanisms which control these pathways. In parallel, in collaboration with Dr.S.Farmer, we will analyze production and compartmentalization of the secreted molecules in cell lines which selectively express individual adipogenic transcription factors in order to determine the role of these factors in the onset of adipocyte s secretion. We will also determine whether or not the same genetic program is required for the onset of secretion and insulin-sensitive glucose uptake in differentiating adipose cells. Thus, we propose to provide compositional, functional, and developmental characterization of the secretory pathway(s) in adipocytes and to determine molecular differences as well as a possible cross-talk between this pathway and the insulin-regulated translocation of Glut4.

脂肪细胞产生并秘密培训激素瘦素，细胞因子TNF-α和酶脂蛋白脂肪酶或LPL。 所有这些蛋白质在控制营养，能量平衡和胰岛素敏感性以及与这些参数直接或间接连接的多种生理条件中起着关键作用。 因此，生理上重要的蛋白质的分泌以及甘油三酸酯的储存和胰岛素敏感的葡萄糖转运，可以被视为脂肪组织最重要的功能之一。 目前，尚不清楚脂肪细胞的分泌是组成型还是调节，而膜结构，例如代表这些细胞中分泌途径的分泌囊泡和/或颗粒，尚未鉴定出来。 我们建议探索大鼠脂肪细胞不同亚细胞分数（内质网（内质网），Golgi appatus，plasmammbrane等），使用一种经典的生物化学技术（或渐变的阶梯）（渐变的ggel geel geel geel g e骨）（内质网膜，质膜等），瘦素，TNF-Alpha，LPLA和其他分泌的蛋白质的分隔具有特定抗体的免疫吸附。我们还建议在脂肪细胞中鉴定构成性分泌途径，并一方面将分泌分子的细胞内分室化与胰岛素敏感的Glut4含量囊泡的构成性分泌囊泡。我们将借助各种促分泌物的脂肪细胞分泌过程，以及涉及膜流量的关键酶的特定抑制剂，例如PI 3-激酶，ARF，V-Type ATPase（Proton Pump）（质子泵）等。 在这项工作的过程中，我们希望确定分泌和GLUT4易位是否代表脂肪细胞中膜运输的不同途径，并深入了解控制这些途径的分子机制。 同时，我们将与博士。Farmer合作，我们将分析细胞系中分泌分子的生产和分区化，这些分子有选择地表达单个脂肪生成转录因子，以确定这些因素在脂肪细胞分泌的发作中的作用。 我们还将确定在分化的脂肪细胞中分泌和胰岛素敏感的葡萄糖摄取是否需要相同的遗传程序。 因此，我们建议在脂肪细胞中提供分泌途径的组成，功能和发育表征，并确定该途径与胰岛素调节的GLUT4转运之间的分子差异以及可能的串扰。