INSULIN SIGNALING DEFECTS IN PCOS

多囊卵巢综合征中的胰岛素信号缺陷

基本信息

批准号：
7255640
负责人：
Ricardo Azziz
金额：
$ 31.65万
依托单位：
CEDARS-SINAI MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2006
资助国家：
美国
起止时间：
2006-07-05 至 2011-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7255640
关键词：
1-Phosphatidylinositol 3-Kinase 70-kDa Ribosomal Protein S6 Kinases A kinase anchoring protein Abdomen Adipocytes Adipose tissue Adrenal Glands Affect Age Androgens Basic Science Binding Binding Proteins Biological Markers Biopsy Classification Clinical Collaborations Consult Critical Pathways Cyclic AMP-Dependent Protein Kinases Data Defect Deoxyglucose Disease Economic Burden Endocrinologist Etiology FOXO1A gene FRAT1 gene Funding Future Glycogen Synthase Kinase 3 Hormonal Hyperandrogenism Hyperinsulinism In Vitro Insulin Insulin Receptor Insulin Resistance Invasive Laboratories Longevity Longitudinal Studies MAP Kinase Gene MAPK14 gene MAPK8 gene Mediating Metabolic Molecular Nature Needles Ovarian Pathway interactions Patients Phenotype Phosphoinositide-3-Kinase, Catalytic, Gamma Polypeptide Phosphorylation Physiology Play Polycystic Ovary Syndrome Polymerase Chain Reaction Population Procedures Protein Kinase C Proteins Proto-Oncogene Proteins c-akt Race Receptor Signaling Recruitment Activity Regulation Relative (related person)Research Research Infrastructure Research Personnel Reverse Transcription Role Sampling Scientist Serine Signal Transduction Staging Steroid biosynthesis Study Subject Surgeon Techniques Testing Time Tissue Sample Tissues Transfection Translations Tyrosine Up-Regulation Western Blotting Woman adenoviral-mediated citrate carrier concept experience glucose transport glucose uptake human MAP2K1 protein in vitro Model in vivo inhibitor/antagonist insulin receptor substrate 1 protein insulin signaling intravenous glucose tolerance test novel programs receptor binding reproductive research study response skills stress-activated protein kinase 1 subcutaneous uptake

项目摘要

DESCRIPTION (provided by applicant): The polycystic ovary syndrome (PCOS) affects ~7% of women and ~70% demonstrate insulin resistance, with the resulting hyperinsulinemia stimulating androgen excess. The economic burden of the disorder is estimated to exceed 4 billion dollars annually, in the U.S. and during the reproductive life span alone. The broad long-term objective of our studies is to establish the molecular etiology(s) of the PCOS-associated insulin resistance. Overall, little is know about the molecular aspects of insulin signaling in PCOS. Insulin-stimulated glucose uptake is deficient in PCOS, suggesting an alteration along the IRS/PI-3 kinase/Akt cascade, although the mitogenic activity and MAPK pathway appears unaffected. Insulin receptor (IR) tyrosine autophosphorylation also appears to be lower, and serine phosphorylation higher. In addition, we have obtained preliminary data indicating that PCOS adipocytes have deficient serine (inhibitory) and increased tyrosine (activating) glycogen synthase kinase-3 (GSK3) phosphorylation, consistent with enhanced GSK3 action. This data suggests that GSK3 dysregulation may represent a novel mechanism for insulin resistance in PCOS. We propose the following studies: Aim 1: To determine the role that defective regulation of GSK3 plays in mediating the abnormal IR signaling and glucose transport of PCOS; we will phenotype, including performing a frequently sampled intravenous glucose tolerance test, 70 PCOS patients and 70 matched controls; and in the adipocytes of these subjects determine the association of GSK3 activity with 2-deoxyglucose uptake; the content of regulators and substrates for GSK phosphorylation, determined by RT-PCR and/or Western blot (including total and phosphorylated IR substrate-1 and 2 [IRS-1/2], Akt, the PI-3 kinase subunits p110a and p110p, the 220-kDa A-kinase anchoring protein [AKAP220], protein kinase C [PKC], p70S6K, and the 2 GSK3-binding proteins known as FRAT1 and FRAT2); the impact of specific PKA, PKB (Akt), and PKC inhibition; in PCOS, the impact of specific GSK3 inhibition; and, in controls, the effect of GSKSbeta upregulation, using adenoviral-mediated transfection. Aim 2: To test whether abnormal signaling of the IRS/PI-3 kinase/Akt, but not the MAPK cascade, is present in PCOS; determining the degree of IR binding and 2-deoxyglucose uptake; and by RT-PCR and/or Western blot, the total content and phosphorylation in response to insulin of the IR, total and translocated GLUT-4, and of critical intermediate proteins (e.g. FKHR of the PI-3 kinase/Akt cascade: c-Raf, MEK-1, ERK1/2, pQORSK, and the translational regulator p70S6, of the ERK1/2 cascade: JNK of the SAPK/JNK cascade; and p38 MAPK of the P38MAPK cascade). Overall, these studies have the potential of elucidating the etioloaic mechanism(s) in PCOS, and guiding our search for therapies and molecular markers.

描述（由申请人提供）：多囊卵巢综合征（PCOS）影响约7％的女性，约70％的女性表现出胰岛素抵抗，导致的高胰岛素血症刺激了雄激素过量。据估计，在美国以及仅在生殖寿命期间，这种疾病的经济负担估计每年超过40亿美元。我们研究的广泛长期目标是建立与PCOS相关的胰岛素抵抗的分子病因。总体而言，对PCOS中胰岛素信号的分子方面知之甚少。胰岛素刺激的葡萄糖吸收在PCOS中缺乏，表明沿IRS/PI-3激酶/AKT级联反应发生了变化，尽管有丝分裂活性和MAPK途径似乎不受影响。胰岛素受体（IR）酪氨酸自磷酸化似乎也较低，丝氨酸磷酸化更高。此外，我们还获得了初步数据，表明PCOS脂肪细胞具有缺乏丝氨酸（抑制）和酪氨酸（激活）糖原合酶激酶3（GSK3）磷酸化的增加，与GSK3动作增强一致。该数据表明，GSK3失调可能代表了PCOS中胰岛素抵抗的新机制。我们提出以下研究：目标1：确定GSK3发挥不良调节在介导PCOS异常的IR信号传导和葡萄糖转运中的作用；我们将表型，包括进行经常采样的静脉葡萄糖耐受性测试，70名PCOS患者和70个匹配对照；在这些受试者的脂肪细胞中，确定了GSK3活性与2-脱氧葡萄糖摄取的关联。 the content of regulators and substrates for GSK phosphorylation, determined by RT-PCR and/or Western blot (including total and phosphorylated IR substrate-1 and 2 [IRS-1/2], Akt, the PI-3 kinase subunits p110a and p110p, the 220-kDa A-kinase anchoring protein [AKAP220], protein kinase C [PKC], P70S6K和2 GSK3结合蛋白称为FRAT1和FRAT2）；特定PKA，PKB（AKT）和PKC抑制的影响；在PCOS中，特定GSK3抑制作用的影响；并且，在对照中，使用腺病毒介导的转染，Gsksbeta上调的作用。目标2：测试IRS/PI-3激酶/AKT的异常信号传导，而不是MAPK级联反应，而不是PCOS中存在；确定IR结合的程度和2-脱氧葡萄糖的摄取；通过RT-PCR和/或Western Blot，响应于IR，总和和易位的GLUT-4和关键中间蛋白的总含量和磷酸化（例如PI-3激酶/Akt cascade的FKHR） SAPK/JNK CASCADE的JNK；总体而言，这些研究具有阐明PCOS中的叶酸机制的潜力，并指导我们寻找疗法和分子标记物。