The transcription factor COUP-TFII is negatively regulated by insulin and glucose via Foxo1- and ChREBP-controlled pathways.
COUP-TFII has an important role in regulating metabolism in vivo. We showed this previously by deleting COUP-TFII from pancreatic beta cells in heterozygous mutant mice, which led to abnormal insulin secretion. Here, we report that COUP-TFII expression is reduced in the pancreas and liver of mice refed with a carbohydrate-rich diet and in the pancreas and liver of hyperinsulinemic and hyperglycemic mice. In pancreatic beta cells, COUP-TFII gene expression is repressed by secreted insulin in response to glucose through Foxo1 signaling. Ex vivo COUP-TFII reduces insulin production and secretion. Our results suggest that beta cell insulin secretion is under the control of an autocrine positive feedback loop by alleviating COUP-TFII repression. In hepatocytes, both insulin, through Foxo1, and high glucose concentrations repress COUP-TFII expression. We demonstrate that this negative glucose effect involves ChREBP expression. We propose that COUP-TFII acts in a coordinate fashion to control insulin secretion and glucose metabolism.
Perilhou
Anaïs
A
Department of Endocrinology, Metabolism, and Cancer, Institut Cochin, Université Paris Descartes, CNRS (UMR 8104), Paris, France.
Tourrel-Cuzin
Cécile
C
Kharroubi
Ilham
I
Henique
Carole
C
Fauveau
Véronique
V
Kitamura
Tadahiro
T
Magnan
Christophe
C
Postic
Catherine
C
Prip-Buus
Carina
C
Vasseur-Cognet
Mireille
M