The Role of ChREBP in Fructose Induced Metabolic Disease

代谢综合征是一系列疾病，包括肥胖、高甘油三酯血症、 高血压、非酒精性脂肪性肝病和胰岛素抵抗易发生 糖尿病和心血管疾病。过量的糖类消费，主要是以糖的形式- 含糖饮料，会促进代谢综合征的发展。它们的作用机制 过量摄入果糖导致代谢性疾病仍不确定。碳水化合物响应性- 元件结合蛋白(ChREBP)是一种由糖类产物激活的转录因子 代谢和调节代谢基因程序和全身糖和脂平衡。中国的SNPs 全基因组关联研究中发现的ChREBP基因座可预测中国人代谢综合征的特征 人类人口。肝脏和肠道ChREBP对果糖摄取高度敏感。肠失禁 ChREBP由于果糖吸收不良而导致果糖不耐受。相比之下，肝脏ChREBP的丢失是 对果糖引起的代谢性疾病具有良好的耐受性和保护作用。有些小鼠品系高度敏感 对果糖引起的疾病具有很强的抵抗力，而其他的则具有高度的抵抗力。初步数据表明，这种易感性 可能是由肠道果糖吸收和代谢的相对差异介导的，这可能会影响 将果糖输送到对肝脏有害的地方。了解肠道的分子决定因素 与肝脏果糖代谢相比，可能对饮食诱导的易感性有重要意义 疾病。通过遗传和饮食模型的结合，我们将研究生理、分子和 ChREBP介导的肠道和肝脏果糖代谢保护OR的遗传机制 导致果糖引起的疾病。在目标1中，使用肠道特异的、功能丧失的小鼠模型，我们 将探讨肠道果糖代谢在调节内源性葡萄糖产生和 调节果糖引起的疾病。在目标2中，我们将确定净利与弊 肝脏ChREBP的激活效应可能依赖于代谢激素FGF21。在目标3中，使用 果糖敏感和果糖耐药小鼠结合肠道器官模型，我们将探索 引起肠道果糖吸收、代谢和代谢差异的分子机制 对果糖引起的疾病的敏感性。我们预计，这些研究将为我们提供对 果糖诱导的代谢性疾病的机制，并为新的策略奠定了基础 预防和治疗肥胖和糖尿病。

The metabolic syndrome is a cluster of disorders that includes obesity, hypertriglyceridemia, hypertension, non-alcoholic fatty liver disease and insulin resistance which predispose to the development of diabetes and cardiovascular disease. Excessive sugar consumption, predominantly in the form of sugar- sweetened beverages, can contribute to the development of the metabolic syndrome. The mechanisms by which excessive fructose consumption contributes to metabolic disease remain uncertain. Carbohydrate Responsive- Element Binding Protein (ChREBP) is a transcription factor which is activated by products of carbohydrate metabolism and regulates metabolic gene programs and systemic glucose and lipid homeostasis. SNPs in the ChREBP locus identified in genome-wide association studies predict features of the metabolic syndrome in human populations. Hepatic and intestinal ChREBP are highly responsive to fructose ingestion. Loss of intestinal ChREBP results in fructose-intolerance due to fructose malabsorption. In contrast, loss of hepatic ChREBP is well-tolerated and protects against fructose-induced metabolic disease. Some mouse strains are highly sensitive to fructose-induced disease whereas others are highly resistant. Preliminary data suggests that this susceptibility may be mediated by relative differences in intestinal fructose absorption and metabolism, which may affect delivery of fructose to the liver where it is deleterious. Understanding the molecular determinants of intestinal versus hepatic fructose metabolism may have important implications for the susceptibility to diet-induced disease. Through a combination of genetic and dietary models, we will investigate physiological, molecular, and genetic mechanisms by which ChREBP-mediated intestinal and hepatic fructose metabolism protect against or contribute to fructose-induced disease. In Aim 1, using an intestine-specific, loss-of-function mouse model, we will explore the importance of intestinal fructose metabolism in regulating endogenous glucose production and mediating fructose-induced disease. In Aim 2, we will determine whether the net beneficial versus adverse effects of hepatic ChREBP activation may be dependent on the metabolic hormone FGF21. In Aim 3, using fructose sensitive and fructose resistant mice in combination with an intestinal organoid model, we will explore the molecular mechanisms giving rise to differences in intestinal fructose absorption, metabolism, and susceptibility to fructose-induced disease. We anticipate that these studies will provide fundamental insight into mechanisms of fructose-induced metabolic disease and lay the groundwork for novel strategies for the prevention and treatment of obesity and diabetes.