Fructose Induced Regulation of Profibrogenic Factors in Hepatic Nonparenchymal Cells

项目总结 NAFLD在当今社会中已变得越来越普遍，影响着成年人和儿童。高 食用果糖玉米糖浆与糖尿病、肥胖和非酒精性脂肪密切相关 肝病(NAFLD)。NAFLD患者的果糖摄入量高出两到三倍 与对照组相比，小叶炎症和纤维化的存在增加。少校 小叶炎症和纤维化的贡献者是激活的肝脏非实质细胞(NPC)， 由肝星状细胞(HSCs)和枯否细胞组成。果糖代谢一直是 主要在肝细胞中研究，已知可诱导脂肪生成和氧化应激。这些 肝细胞中的事件已被证明影响库普弗细胞的功能，将细胞推向 炎症表型。然而，果糖代谢对鼻咽癌细胞表型和 非酒精性脂肪性肝病的功能尚不清楚。该项目广泛的长期目标是确定新的机制 通过揭示代谢途径，过量的果糖导致NAFLD的发展 受果糖调节，影响npc功能。初步数据显示，初级库普弗 细胞和HSCs在体内表达KHK和果糖，增加组织抑制因子 枯否细胞中金属蛋白酶(TIMP1)表达与添加葡萄糖的比较 或者饮用水中没有单糖。在体外，果糖处理会增加细胞内的 巨噬细胞中的醋酸盐和甲酸盐。基于这些观察，这个项目的具体目标是 1)在体外确定果糖驱动纤维形成原表型的机制。 Kupffer细胞的表型和果糖代谢的特征 正常和NAFLD肝脏条件下的果糖消耗。我们的研究设计同时使用了 体内和体外系统，以调查拟议的目的。我们集成了核磁共振 和液质联用法在体外(AIM 1)和体内(AIM 2)示踪13C果糖 并鉴定调节纤维化基因和蛋白的果糖代谢产物 在NPC中的表达。探讨TIMP-1和乙酸乙酯在枯否细胞中的作用 RNA(SiRNA)转基因(AIM 1)将在体外使用。从这项提案中获得的数据是可望的 为鼻咽癌碳水化合物代谢的新机制奠定基础，并提供关键的 对预防和治疗NAFLD的治疗靶点的潜在发展的洞察。

PROJECT SUMMARY NAFLD has become progressively more common in today's society impacting adults and children. High fructose corn syrup consumption is strongly correlated with diabetes, obesity and nonalcoholic fatty liver disease (NAFLD). Fructose consumption is two to three times higher in patients with NAFLD compared to controls and increases the presence of lobular inflammation and fibrosis. The major contributors of lobular inflammation and fibrosis are activated hepatic nonparenchymal cells (NPCs), which consist of hepatic stellate cells (HSCs), and Kupffer cells. Fructose metabolism has been investigated primarily in hepatocytes and is known to induce lipogenesis and oxidative stress. These events in hepatocytes have been shown to impact Kupffer cell function pushing the cells to an inflammatory phenotype. However, the distinct role of fructose metabolism on NPCs phenotype and function in NAFLD is unclear. The broad, long term goals of this project are to identify new mechanism by which fructose excess leads to the development of NAFLD, by uncovering metabolic pathways regulated by fructose that impact NPCs function. Preliminary data demonstrate that primary Kupffer cells and HSCs express KHK and fructose supplementation in vivo, increases tissue inhibitor of metalloproteinase (TIMP1) expression in Kupffer cells compared to diets supplemented with glucose or no monosaccharides in drinking water. In vitro, fructose treatment increases intracellular levels of acetate and formate in macrophages. Based on these observations, the specific aims of this project are: 1) to determine in vitro the mechanism by which fructose drives a profibrogenic phenotype in Kupffer cells and 2) characterize the phenotype and fructose metabolism in Kupffer cells under high fructose consumption during normal and NAFLD liver conditions. Our research design uses both in vivo and in vitro systems, to investigate the proposed aims. We integrate nuclear magnetic resonance and liquid chromatography mass spectrometry to trace 13C fructose in vitro (Aim 1) and in vivo (Aim 2) in Kupffer cells and to identify fructose generated metabolites that regulate fibrogenic gene and protein expression in NPCs. To investigate the role of TIMP-1 and acetate in Kupffer cells, small interfering RNA (siRNA) transfections (Aim 1) will be used in vitro. Data obtained from this proposal are expected to establish a foundation for new mechanisms of carbohydrate metabolism in NPCs and provide critical insight for the potential development of therapeutic targets for the prevention and treatment of NAFLD.