Adiporedoxin, a Novel Player in Adipokine Secretion

Adiporedoxin，脂肪因子分泌的新参与者

基本信息

批准号：
8636466
负责人：
PAUL F PILCH
金额：
$ 35.6万
依托单位：
BOSTON UNIVERSITY MEDICAL CAMPUS
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-04-16 至 2016-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8636466
关键词：
Active Sites Acute Address Adipocytes Adipose tissue Adrenergic Agents Affect Area Biology Blood Body Weight Brain Cell Line Cell membrane Cells Cellular Stress Complement Cysteine DNA Sequence Rearrangement Data Development Diet Disease Dominant-Negative Mutation Drug or chemical Tissue Distribution Endoplasmic Reticulum Energy Metabolism Enzymes Event Family Fatty Acids Fatty acid glycerol esters Gene Targeting Goals Health Hormones Human Hydrogen Peroxide Hypoxia Immunoprecipitation In Vitro Infection Insulin Insulin Receptor Insulin Resistance Leptin Lipids Liver Mass Spectrum Analysis Mediating Membrane Membrane Proteins Molecular Molecular Chaperones Mono-S Mus Muscle Names Obesity Organ Organism Oxidation-Reduction Physiological Process Production Property Proteins Proteome Quality Control Regulation Role Stress Structure Substrate Interaction Testing Testis Therapeutic Thioredoxin Tissues Transfection Tunicamycin adiponectin adipsin adrenergic blood glucose regulation cell type cytokine diabetic disulfide bond endoplasmic reticulum stress energy balance feeding insulin sensitivity lipoprotein lipase meetings member mutant novel peroxiredoxin protein folding protein function research study resistin response small hairpin RNA

项目摘要

DESCRIPTION (provided by applicant): The long-term goals of this project are to reveal mechanisms by which adipocytes function to regulate energy balance and metabolism in humans. Adipocytes secrete a variety of physiologically important proteins including the adipokines (adipose-derived cytokines) leptin and adiponectin. The assembly and secretion of these and other adipokines is initiated in the endoplasmic reticulum (E.R.) where various chaperones and redox-sensitive enzymes are involved in protein folding and disulfide bond formation. We recently discovered a novel membrane protein of the E.R. that is a member of the thioredoxin/peroxiredoxin family. We named it adiporedoxin (Arx) because it is expressed to a significant degree only in white and brown in adipocytes as well as in testes, and its function, like that of related proteins, is to assist in disulfide bond formation and protein folding. Our preliminary data show that by altering the expression of adiporedoxin, we can corresponding alter the levels of secreted adipsin (a complement-related adipokine) and adiponectin, an important adipokine whose levels correlate positively with insulin sensitivity. Moreover, over and under expression of adiporedoxin in cultured mouse adipocytes causes corresponding changes in the amount of the insulin receptor. What these three proteins have in common, aside for important physiological functions, is the need for multiple disulfide bonds in their tertiary and quaternary structure. Our preliminary data support the hypothesis that adiporedoxin may be a major regulator of adipocyte protein assembly and secretion. We will test this hypothesis in Aim1 where mechanistic properties of Arx related to protein assembly and secretion will be investigated in co-transfection experiments with adipokines. In Aim2 we will use adipocytes and various Arx constructs to determine how this protein functions in its physiological milieu in vitro We will interrogate the entire proteome, the secretome and the plasma membrane proteome of Arx over and under expressing fat cells. In Aim3 will determine the effects of endoplasmic stress and obesity on Arx function with regard to adipokines and other possible substrates.. Taken together, the proposed experimentation will reveal fundamental aspect of eukaryotic biology, the function of the endoplasmic reticulum in protein folding and disulfide bond assembly. This very important area of quality control for proteins secreted from adipocytes has been minimally investigated, and the topic has important consequences for human health and disease. If adipokine production is disrupted by changes in adiporedoxin expression, it is highly likely that long-term negative consequences for the organism will occur such as obesity and insulin resistance. By understanding the mechanism of Arx action, these consequences can be addressed by appropriate therapeutic strategies.

描述（由申请人提供）：该项目的长期目标是揭示脂肪细胞功能来调节人类能量平衡和代谢的机制。脂肪细胞分泌多种在生理上重要的蛋白质，包括脂肪因子（脂肪衍生的细胞因子）瘦素和脂联素。这些和其他脂肪因子的组装和分泌是在内质网（E.R.）中启动的，其中各种伴侣和氧化还原敏感酶参与蛋白质折叠和二硫键键的形成。我们最近发现了E.R.的一种新型膜蛋白，该蛋白是硫氧还蛋白/过氧蛋白家族的成员。我们将其命名为adiporedoxin（ARX），因为它仅在脂肪细胞和睾丸中的白色和棕色表达，其功能（如相关蛋白质）是为了帮助二硫键键的形成和蛋白质折叠。我们的初步数据表明，通过改变脂肪氧蛋白的表达，我们可以相对应改变分泌脂肪素（一种与补体相关的脂肪因子）和脂联素的水平，脂联蛋白是一种重要的脂肪因子，其水平与胰岛素敏感性正相关。此外，在培养的小鼠脂肪细胞中脂肪氧蛋白的表达超过，导致胰岛素受体量的相应变化。除了重要的生理功能方面，这三种蛋白质所具有的共同点是需要在其第三纪和第四纪结构中进行多个二硫键。我们的初步数据支持以下假设：脂肪氧蛋白可能是脂肪细胞蛋白质组装和分泌的主要调节剂。我们将在AIM1中检验这一假设，在AIM1中，将在与脂肪因子的共转染实验中研究与蛋白质组装和分泌有关的ARX的机械性能。在AIM2中，我们将使用脂肪细胞和各种ARX构建体来确定该蛋白在其体外的生理环境中的作用，我们将在表达脂肪细胞上和下方质疑ARX的整个蛋白质组，分泌组和质膜蛋白质组。在AIM3中将确定内质应力和肥胖对ARX功能在脂肪因子和其他可能的底物方面的影响。总之，提出的实验将揭示真核生物学的基本方面集会。对脂肪细胞分泌的蛋白质质量控制的非常重要的领域已被最少研究，该主题对人类健康和疾病产生了重要影响。如果脂肪因子的产生因脂肪氧蛋白表达的变化而破坏，那么对生物体的长期负面影响很可能会发生，例如肥胖和胰岛素抵抗。通过了解ARX作用的机制，可以通过适当的治疗策略来解决这些后果。