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：
7417475
负责人：
Ricardo Azziz
金额：
$ 31.02万
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/7417475
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，由此产生的高胰岛素血症会刺激雄激素过多。据估计，在美国，仅在生育期内，这种疾病每年造成的经济负担就超过 40 亿美元。我们研究的广泛长期目标是确定 PCOS 相关胰岛素抵抗的分子病因。总体而言，人们对多囊卵巢综合征中胰岛素信号传导的分子方面知之甚少。 PCOS 患者缺乏胰岛素刺激的葡萄糖摄取，这表明 IRS/PI-3 激酶/Akt 级联发生了改变，尽管促有丝分裂活性和 MAPK 通路似乎不受影响。胰岛素受体 (IR) 酪氨酸自磷酸化似乎也较低，丝氨酸磷酸化较高。此外，我们还获得了初步数据，表明 PCOS 脂肪细胞丝氨酸（抑制性）缺陷和酪氨酸（激活性）糖原合酶激酶 3 (GSK3) 磷酸化增加，这与 GSK3 作用增强一致。该数据表明，GSK3 失调可能代表了 PCOS 患者胰岛素抵抗的一种新机制。我们建议进行以下研究：目标 1：确定 GSK3 的缺陷调节在介导 PCOS 异常 IR 信号和葡萄糖转运中所起的作用；我们将对 70 名 PCOS 患者和 70 名匹配的对照者进行表型分析，包括进行频繁采样的静脉内葡萄糖耐量测试；并在这些受试者的脂肪细胞中确定 GSK3 活性与 2-脱氧葡萄糖摄取的关联； GSK 磷酸化调节剂和底物的含量，通过 RT-PCR 和/或蛋白质印迹测定（包括总的和磷酸化的 IR 底物-1 和 2 [IRS-1/2]、Akt、PI-3 激酶亚基 p110a 和 p110p 、220-kDa A 激酶锚定蛋白 [AKAP220]、蛋白激酶 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，特异性 GSK3 抑制的影响；在对照中，使用腺病毒介导的转染观察 GSKSbeta 上调的效果。目标 2：测试 PCOS 中是否存在 IRS/PI-3 激酶/Akt（而非 MAPK 级联）的异常信号传导；测定IR结合程度和2-脱氧葡萄糖摄取；并通过RT-PCR和/或蛋白质印迹，IR、总的和易位的GLUT-4以及关键中间蛋白（例如PI-3激酶/Akt级联的FKHR：c [0100]-ERK1/2级联的Raf、MEK-1、ERK1/2、pQORSK和翻译调节因子p70S6：SAPK/JNK级联的JNK；和P38MAPK 级联的 p38 MAPK）。总体而言，这些研究有可能阐明 PCOS 的病因机制，并指导我们寻找治疗方法和分子标记。