TOX4 integrates hormone signaling on hepatic glucose and lipid metabolism

TOX4 整合肝脏葡萄糖和脂质代谢的激素信号传导

• 批准号: 10460521
• 负责人: Liheng Wang
• 金额: $ 13.1万
• 依托单位: ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-04 至 2023-08-09
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10460521
• 关键词: Ablation; Adenoviruses; Affinity; Affinity Chromatography; Albumins; American; Beta Cell; Biological Assay; Blood Glucose; Breeding; Chromatin; DNA; Data; Diabetes Mellitus; Diagnosis; Diet; Enzymes; FOXO1A gene; Failure; Family; Family member; Fasting; Gene Expression; Genes; Genetic Transcription; Gluconeogenesis; Glucose; Hepatic; Hepatocyte; Heterogeneity; High Fat Diet; Hormones; Hyperglycemia; Impairment; In Vitro; Insulin; Insulin Receptor; Insulin Resistance; Intervention; Knock-out; Knockout Mice; Liver; LoxP-flanked allele; Mass Spectrum Analysis; Mediating; Medical; Metabolic; Metabolism; Molecular; Mus; Non-Insulin-Dependent Diabetes Mellitus; Pathologic; Pathway interactions; Phosphoenolpyruvate Carboxylase; Physiological; Physiology; Play; Post-Translational Protein Processing; Prevention; Process; Proteins; Regulation; Research; Resistance; Role; Sampling; Testing; Transcription Coactivator; Transcriptional Regulation; Transposase; blood glucose regulation; db/db mouse; diabetic; diet-induced obesity; glucose metabolism; glucose production; glucose tolerance; glucose-6-phosphatase; glycogenolysis; hormonal signals; improved; in vivo; insulin regulation; insulin sensitivity; knock-down; lipid biosynthesis; lipid metabolism; member; metabolic abnormality assessment; novel; novel therapeutic intervention; oxidation; prevent; promoter; response; small hairpin RNA; success; therapeutic target; transcription factor; transcriptome sequencing

Project Summary One in every 10 Americans is diagnosed with diabetes, and 90% of them have type 2 diabetes (T2D) due to insulin resistance and beta cell failure. Prevention and treatment of T2D remain an unmet medical need. The liver produces glucose during fasting to maintain normal blood glucose levels. This process is dysregulated in T2D, when resistance to or lack of insulin increases glucose production, resulting in hyperglycemia and its complications. Insulin regulation of hepatocyte glucose production (HGP) requires rapid changes in gene expression. FoxO1 plays an essential role in the transcriptional regulation of HGP. FoxO1 ablation impairs, but does not completely abolish the regulation of glucose production by insulin, likely due to incomplete suppression of phosphoenolpyruvate carboxykinase (Pck1) gene expression. These data highlight the heterogeneity of transcription factors (TFs) in regulating glucose production. The PI has recently identified TOX High Mobility Group Box Family Member 4 (TOX4) as a novel insulin-regulated TF, using DNA affinity purification from the Pck1 promoter and mass spectrometry (MS) in primary hepatocytes and liver samples. However, the metabolic function of TOX4 is unknown. In preliminary data, she shows that TOX4 is a transcriptional activator of Pck1 and glucose-6-phosphatase (G6pc). Knockdown of Tox4 in primary hepatocytes reduces glucose production by repressing these two genes. Moreover, in vivo KD of Tox4 in liver using adenovirus-encoded shRNA significantly inhibits gluconeogenesis and improves glucose tolerance and insulin sensitivity in C57BL/6J mice, while simultaneously promoting lipogenesis. These changes are more pronounced in diet-induced-obese (DIO) and diabetic db/db mice. Therefore, she hypothesizes that TOX4 regulates glucose and lipid metabolism in response to hormones. In this application, she will generate mice to ablate TOX4 in hepatocytes and critically investigate the function of TOX4 in hepatic glucose and lipid metabolism (Aim 1). She will further examine the mechanisms underlying hepatic TOX4 activation and regulation of its downstream targets (Aim 2). Successful completion of this application will illustrate the role of a new TF in regulating glucose and lipid metabolism in the liver in response to insulin. More importantly, these proposed studies will determine whether TOX4 is a potential therapeutic target in the treatment of insulin resistance and T2D.

项目摘要 每10名美国人中有一个被诊断出患有糖尿病，其中90％的人患有2型糖尿病（T2D） 胰岛素抵抗和β细胞衰竭。预防和治疗T2D仍然是未满足的医疗需求。这 肝脏在禁食过程中产生葡萄糖，以维持正常的血糖水平。此过程失调 T2D，当抗胰岛素的耐药性或缺乏胰岛素时会增加葡萄糖的产生，导致高血糖及其 并发症。肝细胞葡萄糖产生（HGP）的胰岛素调节需要快速变化基因 表达。 FOXO1在HGP的转录调节中起着至关重要的作用。 FOXO1消融障碍，但 不会完全废除胰岛素对葡萄糖产生的调节，这可能是由于不完整的 抑制磷酸烯醇丙酮酸羧基酶（PCK1）基因表达。这些数据突出显示了 转录因子（TFS）调节葡萄糖产生的异质性。 PI最近确定了托克斯 高移动性组盒家庭成员4（TOX4）作为一种新型胰岛素调节的TF，使用DNA亲和力 原代肝细胞和肝样品中PCK1启动子和质谱（MS）的纯化。 但是，TOX4的代谢功能尚不清楚。在初步数据中，她表明托克斯是一个 PCK1和葡萄糖-6-磷酸酶（G6PC）的转录激活剂。 tox4在初级中的敲低 肝细胞通过抑制这两个基因来减少葡萄糖的产生。此外，肝中的tox4体内kd 使用腺病毒编码的SHRNA显着抑制糖异生，并提高葡萄糖耐受性和 C57BL/6J小鼠中的胰岛素敏感性，同时促进脂肪生成。这些变化更多 在饮食诱导的肥胖（DIO）和糖尿病DB/DB小鼠中发音。因此，她假设Tox4 响应激素来调节葡萄糖和脂质代谢。在此应用程序中，她将生成老鼠 在肝细胞中烧蚀毒品，并批判性地研究了托克斯在肝葡萄糖和脂质中的功能 代谢（目标1）。她将进一步研究肝毒tox4激活和 调节其下游目标（AIM 2）。成功完成此应用程序将说明 针对胰岛素调节肝脏中葡萄糖和脂质代谢的新TF。更重要的是，这些 拟议的研究将确定托克斯是否是治疗胰岛素治疗的潜在治疗靶标 电阻和T2D。