A novel ChREBP isoform in adipose tissue regulates systemic glucose metabolism.
The prevalence of obesity and type 2 diabetes is increasing worldwide and threatens to shorten lifespan. Impaired insulin action in peripheral tissues is a major pathogenic factor. Insulin stimulates glucose uptake in adipose tissue through the GLUT4 (also known as SLC2A4) glucose transporter, and alterations in adipose tissue GLUT4 expression or function regulate systemic insulin sensitivity. Downregulation of human and mouse adipose tissue GLUT4 occurs early in diabetes development. Here we report that adipose tissue GLUT4 regulates the expression of carbohydrate-responsive-element-binding protein (ChREBP; also known as MLXIPL), a transcriptional regulator of lipogenic and glycolytic genes. Furthermore, adipose ChREBP is a major determinant of adipose tissue fatty acid synthesis and systemic insulin sensitivity. We find a new mechanism for glucose regulation of ChREBP: glucose-mediated activation of the canonical ChREBP isoform (ChREBP-α) induces expression of a novel, potent isoform (ChREBP-β) that is transcribed from an alternative promoter. ChREBP-β expression in human adipose tissue predicts insulin sensitivity, indicating that it may be an effective target for treating diabetes.
Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, USA.
SourceNature 484:7394 2012 Apr 19 pg 333-8
Basic Helix-Loop-Helix Leucine Zipper Transcription Factors
Body Mass Index
Gene Expression Regulation
Glucose Transporter Type 4
Molecular Sequence Data
Promoter Regions, Genetic
Pub Type(s)Journal Article
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't