Estrogen Effects in Insulin Target and Granulosa Cells

描述（由申请人提供）：高脂肪摄入是导致胰岛素敏感性降低的主要环境因素，导致相关胰岛素抵抗性疾病（如X综合征、PCOS、2型糖尿病和肥胖症）的发病率上升。我们已经证明，雌激素化的妇女和雌性啮齿动物的保护，从脂肪诱导的胰岛素抵抗，而男性，和雌激素缺乏的女性是完全容易受到这些不利影响的脂肪。在本申请中，我们计划了一种基础广泛的体内和体外方法来阐明脂肪诱导的胰岛素抵抗的机制和雌激素的保护作用，使用各种新的动物模型系统，体外3 T3-L1脂肪细胞和非经典的胰岛素靶组织卵巢颗粒细胞（GC）。或高脂肪饮食，导致“炎症途径”的激活，并且该途径中的特定丝氨酸/苏氨酸激酶如PKC θ、IKK β或JNK，或作为NfkappaB激活的结果而诱导的基因，反馈胰岛素信号传导系统以引起胰岛素抗性。我们的初步数据表明，在体外用FFA处理3 T3-L1脂肪细胞导致细胞胰岛素抵抗的显着状态，我们将利用这一新的系统进行新的研究，旨在阐明FFA诱导的胰岛素抵抗的分子机制和雌激素对这些影响的保护。最后，由于我们假设来自胰岛素抵抗动物和女性（特别是PCOS）的GC可以是胰岛素/ IGF-I抵抗的功能后果，我们建议在正常大鼠和胰岛素抵抗啮齿动物制备的GC中进行一系列广泛的研究，以确定FFA治疗是否会导致这些细胞中的胰岛素抵抗，因为它在胰岛素靶细胞中，并确定潜在的机制。我们还将研究这些细胞中胰岛素、IGF-I和FSH的基本信号系统。总之，这些研究的结果应大大提高我们的脂肪诱导的胰岛素抵抗的机制，在经典和非经典的胰岛素靶组织的理解，也阐明了雌激素的保护作用的机制。这些研究还应强调炎症通路激活在这些病理生理事件中的作用，这可能对新的治疗方法具有潜在的治疗意义。

DESCRIPTION (provided by applicant): High fat intake is a major environmental factor leading to decreased insulin sensitivity contributing to the rising incidence of interrelated insulin resistant diseases such as Syndrome X, PCOS, Type 2 diabetes mellitus, and obesity. We have demonstrated that estrogenized women and female rodents are protected from fat induced insulin resistance, whereas, males, and estrogen deficient females are fully susceptible to these adverse effects of fat. In this application, we plan a broad based, in vivo and in vitro approach to elucidate the mechanisms of fat induced insulin resistance and the protective effects of estrogens, using various novel animal model systems, 3T3-L1 adipocytes in vitro, and the non-classical insulin target tissue ovarian granulose cells (GCs) An underlying hypothesis in this application is that excess fat metabolism due to elevated FFA levels, or high fat diets, leads to activation of the "inflammatory pathway" and that specific serine/ threonine kinases in this pathway such as PKC theta, IKK beta, or JNK, or genes induced as a result of NfkappaB activation, feedback on the insulin signaling system to cause insulin resistance. Our preliminary data show that treatment of 3T3-L1 adipocytes in vitro with FFAs leads to a marked state of cellular insulin resistance, and we will exploit this novel system to conduct new studies aimed at elucidating the molecular mechanisms of FFA induced insulin resistance and estrogen's protection against these effects. Finally, since we hypothesize that GCs from insulin resistant animals and women (particularly PCOS) can be insulin/ IGF-I resistant with functional consequences, we propose an extensive series of studies in GCs prepared from normal rats and insulin resistant rodents, to determine whether FFA treatment causes insulin resistance in these cells, as it dos in insulin target cells, and to identify the underlying mechanisms. We will also study the basic signaling systems for insulin, IGF-I and FSH in these cells. Taken together the results of these studies should greatly enhance our understanding of the mechanisms of fat induced insulin resistance, in classic and non-classic insulin target tissues, and also elucidate the mechanisms underlying the protective effects of estrogens. These studies should also highlight the role of inflammatory pathway activation in these pathophysiologic events and this may have potential therapeutic implications for new treatment approaches.