Regulation of Insulin Biosynthesis
in Pancreatic beta-cells by Shp2
- Editore:
VDM Verlag
- EAN:
9783639135084
- ISBN:
3639135083
- Pagine:
- 160
- Formato:
- Paperback
- Lingua:
- Tedesco
Descrizione Regulation of Insulin Biosynthesis
Intracellular signaling by which pancreatic beta- cells synthesize and secrete insulin in control of glucose homeostasis is not fully understood. Here we show that Shp2, a cytoplasmic tyrosine phosphatase possessing 2 SH2 domains, coordinates signaling events required for insulin biosynthesis in beta-cells. Mice with conditional ablation of the Shp2/Ptpn11 gene in the pancreas exhibited defective glucosestimulated insulin secretion and impaired glucose tolerance. Consistently, siRNA-mediated Shp2-knockdown in rat insulinoma INS-1 832/13 cells resulted in decreased insulin production and secretion despite an increase in cellular ATP. Shp2 modulates the strength of signals flowing through Akt/FoxO1 and Erk pathways, culminating in control of Pdx1 expression and activity on Ins1 and Ins2 promoters, and forced Pdx1 expression rescued insulin production in Shp2-knockdown beta-cells. Therefore, Shp2 acts as a signal coordinator in beta-cells, orchestrating multiple pathways controlling insulin biosynthesis to maintain glucose homeostasis.
