Biochemical and Biophysical Research Communications, Vol.295, No.1, 174-181, 2002
The mif gene is transcriptionally regulated by glucose in insulin-secreting cells
Macrophage migration inhibitory factor (MIF) is an important regulator of glucose homeostasis. In pancreatic beta-cells, MIF expression is regulated by glucose and its secretion potentiates the glucose-induced insulin secretion. The molecular mechanisms by which glucose mediates its effect on MIF expression are not elucidated. Herein, we report that incubating the differentiated insulin-secreting cell line INS-1 in high glucose concentration increases MIF transcriptional activity as well as the reporter gene activity driven by the -1033 to +63 by fragment of the MIF promoter. A minimal region located between -187 and -98 by of this promoter sequence contributes both to basal activity and glucose-responsiveness of the gene. Within this promoter region, two cis-binding sequences were identified by mobility shift assays and footprinting experiments. Both cis-elements interact with nuclear proteins expressed specifically in insulin-secreting cells. In conclusion, we identified a minimal region of the M IF promoter which contributes to the glucose stimulation of the mif gene in insulin-secreting cells. (C) 2002 Elsevier Science (USA). All rights reserved.
Keywords:macrophage migration inhibitory factor;MIF;glucose;transcription;gene regulation;insulin;secreting cells;cis-elements