GLUT-2 gene transfer into insulinoma cells confers both low and high affinity glucose-stimulated insulin release: Relationship to glucokinase activity

Sarah Ferber, Hector BeltrandelRio, John H. Johnson, Richard J. Noel, Laura E. Cassidy, Samuel Clark, Thomas C. Becker, Steven D. Hughes, Christopher B. Newgard*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

94 Scopus citations

Abstract

The rat insulinoma cell line RIN 1046-38 loses glucosestimulated insulin secretion as a function of time in culture. We found that the loss of glucose sensing in these cells was correlated with the loss of expression of GLUT-2 and glucokinase. Stable transfection of RIN cells with a plasmid containing the GLUT-2 cDNA conferred glucose-stimulated insulin release in intermediate but not high passage cells, with the near-maximal 3-fold increase occurring at 50 μM glucose. GLUT-2 expressing cells also exhibited a larger response to the combination of 5 mM glucose + 1 μM forskolin than untransfected cells (7.9 versus 1.6-2.7-fold, respectively). GLUT-2 expressing intermediate passage, but not high passage, RIN cells exhibited a 4-fold increase in glucokinase enzymatic activity relative to nonexpressing controls. Glucokinase activity was also increased by transfer of the GLUT-2 gene into intermediate passage RIN cells via recombinant adenovirus. Preincubation of GLUT-2 expressing intermediate passage RIN cells with 2-deoxyglucose to inhibit low Km hexokinases resulted in a glucose-stimulated insulin secretion response that was shifted toward the physiologic range. These studies indicate that GLUT-2 expression confers both a high and low affinity glucose-stimulated insulin secretion response to intermediate passage RIN cells.

Original languageEnglish
Pages (from-to)11523-11529
Number of pages7
JournalJournal of Biological Chemistry
Volume269
Issue number15
StatePublished - 15 Apr 1994
Externally publishedYes

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