Attenuation of Expression of γ-Glutamylcysteine Synthetase by Ribozyme Transfection Enhance Insulin Secretion by Pancreatic β Cell Line, MIN6

Autor: Hideaki Kondo, Hironori Yamasaki, Takahiro Abe, Hiroshi Kijima, Hirofumi Takino, Takahito Kondo, Yasunori Sera, Yoshihiko Yamaguchi, Yoshishige Urata, Eiji Kawasaki, Satoko Mori, Kenji Yamakawa, Katsumi Eguchi, Iida Tetsuya, Masako Ozaki
Rok vydání: 2000
Předmět:
Zdroj: Biochemical and Biophysical Research Communications. 278:236-240
ISSN: 0006-291X
DOI: 10.1006/bbrc.2000.3776
Popis: Low levels of intracellular antioxidant enzyme activities as well as glutathione (GSH) concentrations have been described in pancreatic beta cells. We examined the effects of intracellular GSH depletion on insulin secretion and the role of intracellular GSH in signal transduction in beta cell line, MIN6 cells. Anti-gamma-glutamylcysteine synthetase (gamma-GCS) heavy subunit ribozyme was stably transfected to MIN6 cells to reduce intracellular GSH concentration. In the presence of 10 mM glucose, ribozyme-transfected cells (RTC) increased insulin secretion from 0.58 microg/10(6) cells/h in control cells (CC) to 1.48 microg/10(6) cells/h. This was associated with increased intracellular Ca(2+) concentration in RTC, detected by fluo-3 staining. Our results demonstrated that intracellular GSH concentration might influence insulin secretion by MIN6 cells, and suggest that enhanced insulin secretion by beta cells conditioned by chronic depletion of GSH is mediated by increased intracellular Ca(2+) concentration.
Databáze: OpenAIRE