Roles of cytoplasmic Ca2+ and intracellular Ca2+ stores in induction and suppression of apoptosis in S49 cells.

Journal Article (Journal Article)

The Ca2+-ATPase inhibitors, thapsigargin and cyclopiazonic acid, depleted intracellular Ca2+ stores, induced large increases in intracellular Ca2+ concentration, and caused apoptosis in S49 cells. Removal of extracellular Ca2+ augmented apoptosis due to thapsigargin, indicating that depletion of Ca2+ from intracellular stores is responsible for apoptosis with this agent. Overexpression of the apoptosis suppressor, Bcl-2, inhibited apoptosis due to thapsigargin but did not affect thapsigargin-induced Ca2+ signaling. Dexamethasone induced apoptosis, diminished the size of the endoplasmic reticulum Ca2+ pool, and caused a small elevation of intracellular Ca2+. However, this elevation was not due to Ca2+ influx because the increase was similar in the presence or absence of Ca2+ in the medium. Furthermore, in contrast to the results with thapsigargin, apoptosis due to dexamethasone was unchanged in a Ca2+-free medium. These results indicate that depletion of Ca2+ stores initiates a pathway leading to apoptosis. Elevations in cytoplasmic Ca2+ appears to play a lesser role than previously thought in the actions of Bcl-2 and glucocorticoids.

Full Text

Duke Authors

Cited Authors

  • Bian, X; Hughes, FM; Huang, Y; Cidlowski, JA; Putney, JW

Published Date

  • April 1997

Published In

Volume / Issue

  • 272 / 4 Pt 1

Start / End Page

  • C1241 - C1249

PubMed ID

  • 9142849

International Standard Serial Number (ISSN)

  • 0002-9513

Digital Object Identifier (DOI)

  • 10.1152/ajpcell.1997.272.4.C1241


  • eng

Conference Location

  • United States