Pancreatic beta cells require NeuroD to achieve and maintain functional maturity.
NeuroD, a transactivator of the insulin gene, is critical for development of the endocrine pancreas, and NeuroD mutations cause MODY6 in humans. To investigate the role of NeuroD in differentiated beta cells, we generated mice in which neuroD is deleted in insulin-expressing cells. These mice exhibit severe glucose intolerance. Islets lacking NeuroD respond poorly to glucose and display a glucose metabolic profile similar to immature beta cells, featuring increased expression of glycolytic genes and LDHA, elevated basal insulin secretion and O2 consumption, and overexpression of NPY. Moreover, the mutant islets appear to have defective K(ATP) channel-mediated insulin secretion. Unexpectedly, virtually all insulin in the mutant mice is derived from ins2, whereas ins1 expression is almost extinguished. Overall, these results indicate that NeuroD is required for beta cell maturation and demonstrate the importance of NeuroD in the acquisition and maintenance of fully functional glucose-responsive beta cells.
Gu
Chunyan
C
Department of Molecular, Cellular, and Developmental Biology, University of Colorado at Boulder, Boulder, CO 80309-0347, USA.
Stein
Gretchen H
GH
Pan
Ning
N
Goebbels
Sandra
S
Hörnberg
Hanna
H
Nave
Klaus-Armin
KA
Herrera
Pedro
P
White
Peter
P
Kaestner
Klaus H
KH
Sussel
Lori
L
Lee
Jacqueline E
JE
D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000172:deficiency / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D054086:KATP Channels / Q000378:metabolism; D051379:Mice; D009419:Nerve Tissue Proteins / Q000172:deficiency / Q000378:metabolism*; D009478:Neuropeptide Y / Q000378:metabolism; D010101:Oxygen Consumption / Q000502:physiology; D040081:Protein Array Analysis
D051792:Basic Helix-Loop-Helix Proteins; D005947:Glucose; D007328:Insulin; D054086:KATP Channels; D009419:Nerve Tissue Proteins; D009478:Neuropeptide Y; C093564:Neurogenic differentiation factor 1