Diabetes, Vol 49, Issue 6 953-960, Copyright © 2000 by American Diabetes Association
Sulfonylurea receptor 1 and Kir6.2 expression in the novel human insulin-secreting cell line NES2Y
WM Macfarlane, RE O'Brien, PD Barnes, RM Shepherd, KE Cosgrove, KJ Lindley, A Aynsley-Green, RF James, K Docherty and MJ Dunne
School of Biochemistry and Genetics, University of Newcastle upon Tyne, UK.
NES2Y is a proliferating human insulin-secreting cell line that we have
derived from a patient with persistent hyperinsulinemic hypoglycemia of
infancy. This disease is characterized by unregulated insulin release
despite profound hypoglycemia. NES2Y cells, like beta-cells isolated from
the patient of origin, lack functional ATP-sensitive potassium channels
(KATP) and also carry a defect in the insulin gene-regulatory transcription
factor PDX1. Here, we report that the NES2Y beta-cells that are transfected
with the genes encoding the components of KATP channels in beta-cells,
sulfonylurea receptor (SUR) 1 and Kir6.2, have operational KATP channels
and show normal intracellular Ca2+ and secretory responses to glucose.
However, these cells, designated NESK beta-cells, have impaired insulin
gene transcription responses to glucose. NES2Y beta-cells that are
transfected with either Kir6.2 or SUR1 alone do not express functional KATP
channels and have impaired intracellular free Ca2+ concentration-signaling
responses to depolarization-dependent beta-cell agonists. These findings
document that in NES2Y beta-cells, coexpression of both subunits is
critically required for fully operational KATP channels and KATP
channel-dependent signaling events. This article further characterizes the
properties of the novel human beta-cell line, NES2Y, and documents the
usefulness of these cells in diabetes-related research.