ChREBP 在糖脂代谢中的作用的最新进展。
Recent progress on the role of ChREBP in glucose and lipid metabolism.
机构信息
University Hospital Center for Nutritional Support and Infection Control, Gifu University, Gifu 501-1194, Japan.
出版信息
Endocr J. 2013;60(5):543-55. doi: 10.1507/endocrj.ej13-0121. Epub 2013 Apr 19.
Carbohydrate response element binding protein (ChREBP) is a transcription factor activated by glucose that is highly expressed in liver, pancreatic β-cells, brown and white adipose tissues, and muscle. We reported that hepatic suppression of the Chrebp gene improves hepatic steatosis, glucose intolerance, and obesity in genetically obese mice. Moreover, we have studied the role of ChREBP with special reference to feedforward and feedback looping in liver and pancreatic β-cells. Recently, several groups reported that (1) glucose activates ChREBP-α transactivity and in turn ChREBP-α induces ChREBP-β on both transcriptional and translational levels in adipose tissues, and (2) ChREBP regulates glucose transporter type 4 mRNA levels, which may affect glucose uptake in adipose tissues. Moreover, in adipose tissues of obese patients, Chrebpb mRNA levels were much lower than those in lean subjects, while the levels were much higher in liver of obese patients than those in lean subjects. These findings suggest that Chrebpb mRNA levels are different in various tissues and probably in the stages of diabetes mellitus. Herein, we review recent progress in the study of ChREBP with special references to (1) the mechanisms regulating ChREBP transactivity (posttranslational modifications, intramolecular glucose sensing module, feedforward mechanism, and the feedback loop between ChREBP and its target genes), and (2) the role of ChREBP in liver, pancreatic islets and adipose tissues. Understanding the role of ChREBP in each tissue will provide important insight into the pathogenesis of metabolic syndrome.
碳水化合物反应元件结合蛋白(ChREBP)是一种受葡萄糖激活的转录因子,在肝脏、胰腺β细胞、棕色和白色脂肪组织以及肌肉中高度表达。我们报道了肝脏中 Chrebp 基因的抑制可改善遗传性肥胖小鼠的肝脂肪变性、葡萄糖不耐受和肥胖。此外,我们还研究了 ChREBP 的作用,特别是在肝脏和胰腺β细胞中的前馈和反馈循环中的作用。最近,有几个研究小组报道:(1)葡萄糖激活 ChREBP-α的转录活性,反过来 ChREBP-α在转录和翻译水平上诱导脂肪组织中 ChREBP-β的表达;(2)ChREBP 调节葡萄糖转运蛋白 4 mRNA 水平,这可能影响脂肪组织中的葡萄糖摄取。此外,在肥胖患者的脂肪组织中,Chrebpb mRNA 水平明显低于瘦人,而在肥胖患者的肝脏中,Chrebpb mRNA 水平明显高于瘦人。这些发现表明,Chrebpb mRNA 水平在不同组织中存在差异,可能与糖尿病的阶段有关。本文综述了 ChREBP 研究的最新进展,特别关注(1)调节 ChREBP 转录活性的机制(翻译后修饰、分子内葡萄糖感应模块、前馈机制和 ChREBP 与其靶基因之间的反馈循环);(2)ChREBP 在肝脏、胰岛和脂肪组织中的作用。了解 ChREBP 在每个组织中的作用将为代谢综合征的发病机制提供重要的见解。