ChREBP binding to fatty acid synthase and L-type pyruvate kinase genes is stimulated by glucose in pancreatic β-cells

• Published in: Journal of lipid research 2006-11, Vol.47 (11), p.2482-2491
• Main Authors: da Silva Xavier, Gabriela, Rutter, Guy A., Diraison, Frédérique, Andreolas, Chrysovalantis, Leclerc, Isabelle
• Format: Article
• Language: English
• Subjects: Active Transport, Cell Nucleus; Animals; Apoptosis; Base Sequence; Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; chromatin immunoprecipitation; Fatty Acid Synthases - metabolism; Gene Silencing; glucolipotoxicity; Glucose - metabolism; Insulin-Secreting Cells - metabolism; lipogenic genes; Mice; Molecular Sequence Data; Nuclear Proteins - metabolism; Nuclear Proteins - physiology; Protein Binding; Pyruvate Kinase - metabolism; RNA, Small Interfering - metabolism; Transcription Factors - metabolism; Transcription Factors - physiology; Triglycerides - metabolism
• ISSN: 0022-2275; 1539-7262
• DOI: 10.1194/jlr.M600289-JLR200

Pancreatic β-cell dysfunction is central to the pathogenesis of type 2 diabetes and may involve secretory failure through glucolipotoxity. The relative importance of the transcription factors carbohydrate-responsive element binding protein (ChREBP), sterol-responsive element binding protein-1c (SREBP-1c), and upstream stimulatory factor (USF) in the induction of lipogenic genes by glucose remains unclear. By confocal imaging, we show that ChREBP translocates to the nucleus in MIN6 β cells in response to glucose. Both ChREBP and SREBP-1c were required for the induction of the fatty acid synthase (FAS) promoter by glucose, and chromatin immunoprecipitation (ChIP) assay revealed that glucose induced the binding of both ChREBP and SREBP-1c to the FAS promoter without affecting USF2 binding. By contrast, ChIP assay revealed that high glucose prompted direct binding of ChREBP, but not SREBP-1c or USF2, to the liver-type pyruvate kinase (L-PK) promoter. This event was indispensable for the induction of the L-PK gene by glucose, as demonstrated by RNA silencing, single-cell promoter analysis, and quantitative real-time PCR. We conclude that ChREBP is a critical regulator of lipogenic genes in the β cell and may play a role in the development of glucolipotoxicity and β cell failure through alteration of gene expression in type 2 diabetes.