Copper and copper-binding proteins in insulin resistance-associated metabolic disease

项目摘要 我们的长期目标是了解胰岛素抵抗相关的病理机制。 代谢性疾病，特别是非酒精性脂肪肝(NAFLD)。尽管非酒精性脂肪性肝病影响四分之一 美国人和显著增加肝癌和心血管疾病的风险，没有FDA批准 目前存在非酒精性脂肪肝的治疗方法。尽管胰岛素抵抗增加了NAFLD的发生率，但其机制 这些发病机制之间的联系尚不完全清楚，值得进一步研究。 为了确定介导胰岛素抵抗相关的NAFLD的关键因素，我们筛选了糖尿病患者和 健康对照组血浆蛋白浓度和肝脏基因表达的差异我们发现 铜蓝蛋白(Cp)是一种肝脏分泌的铜结合蛋白，在糖尿病患者的肝脏和血浆中升高 病人。这些数据与先前发现的高血浆CP浓度在慢性前列腺炎患者中是一致的 糖尿病或肥胖，且CP与糖尿病严重程度、肥胖、心血管疾病风险和死亡率呈正相关。 此外，我们的初步数据和其他人的数据显示，肝脏CP在人类和 NAFLD啮齿动物，其肝脏铜水平低11-16，与CP降低肝脏的作用一致 铜含量。然而，高肝脏CP和低肝脏铜相关的功能意义 与胰岛素抵抗和非酒精性脂肪肝的关系尚不清楚。 为了解决这一缺陷，我们描述了胰岛素抵抗和肝细胞特异性的小鼠模型。 CP删除。这些初步研究表明，肝脏CP和铜的作用以前没有被认识到 将胰岛素抵抗与NAFLD联系起来。而高脂饮食降低肝脏铜含量，促进非酒精性脂肪肝， 肝脏特异性CP(L-CP KO)基因敲除可增加肝脏铜含量，改变其表达 参与肝脏脂肪代谢的基因，并改善这些胰岛素抵抗小鼠的NAFLD。我们 假设胰岛素抵抗诱导的肝性CP通过破坏铜代谢平衡促进NAFLD 脂类代谢。在目标1中，我们将确定胰岛素抵抗如何诱导肝脏CP基因转录； 目的2，我们将确定肝脏CP如何调节铜稳态和NAFLD的发展； 目的3，我们将阐明肝脏铜稳态失调的分子机制 推广非酒精性脂肪肝。 我们预计，拟议研究的完成将确定肝脏CP和铜在代谢中的作用 胰岛素抵抗状态下NAFLD的调节和发展，可能为治疗提供新的方法 NAFLD。

Project Summary Our long-term goal is to understand the pathologic mechanisms underlying insulin resistance-associated metabolic disease, and in particular non-alcoholic fatty liver disease (NAFLD). Although NAFLD affects 1 in 4 Americans and significantly increases the risk of liver cancer and cardiovascular disease, no FDA-approved NAFLD therapies currently exist. Although insulin resistance increases the incidence of NAFLD, the mechanisms linking these pathologies are not completely understood and warrant further study. To identify the key factors mediating insulin resistance-associated NAFLD, we screened diabetic individuals and healthy controls for differences in plasma protein concentrations and hepatic gene expression We found that ceruloplasmin (CP), a liver-secreted copper-binding protein, was increased in the liver and plasma of diabetic patients. These data are consistent with previous findings of high plasma CP concentrations in individuals with diabetes or obesity, and positive correlations of CP with the severity of diabetes, obesity, CVD risk, and mortality. In addition, our preliminary data and data from others show that hepatic CP expression is high in humans and rodents with NAFLD, while their hepatic copper levels are low11-16, consistent with the role of CP to reduce hepatic copper content. However, the functional significance of the high hepatic CP and low hepatic copper associated with insulin resistance and NAFLD is unclear. To address this deficiency, we have characterized mouse models of insulin resistance and hepatocyte-specific CP deletion. These preliminary studies have suggested a previously unrecognized role of hepatic CP and copper in linking insulin resistance and NAFLD. While a HFD decreases hepatic copper content and promotes NAFLD, liver-specific knockdown or knockout of CP (L-CP KO) increases hepatic copper content, alters the expression of genes involved in hepatic lipid metabolism, and ameliorates NAFLD in these insulin resistant mice. We hypothesize that insulin resistance-induced hepatic CP promotes NAFLD by disrupting copper homeostasis and lipid metabolism. In Aim 1, we will determine how insulin resistance induces hepatic CP gene transcription; in Aim 2, we will determine how hepatic CP regulates copper homeostasis and the development of NAFLD; and in Aim 3, we will elucidate the molecular mechanisms by which dysregulation of hepatic copper homeostasis promotes NAFLD. We expect that the completion of the proposed studies will define the role of hepatic CP and copper in metabolic regulation and the development of NAFLD in insulin resistant states, which may suggest new means of treating NAFLD.