Caspase-dependent apoptosis induced by thapsigargin was prevented by glycogen synthase kinase-3 inhibitors in cultured rat cortical neurons.
Calcium ion is essential for cellular functions including signal transduction. Uncontrolled calcium stress has been linked causally to a variety of neurodegenerative diseases. Thapsigargin, which inhibits Ca(2+)-ATPase in the endoplasmic reticulum (ER) and blocks the sequestration of calcium by the ER, induced apoptotic cell death (chromatin condensation and nuclear fragmentation) accompanied by GRP78 protein expression and caspase-3 activation in rat fetal cortical neurons (days in vitro 9-10). Blockade of N-methyl-D-aspartate (NMDA) receptors with NMDA antagonists induced apoptosis without GRP78 protein expression. Apoptosis accompanied both caspase-9 and caspase-3 activation. We then examined whether GSK-3 is involved in thapsigargin-induced cell death by using GSK-3 inhibitors. We assayed the effects of selective GSK-3 inhibitors, SB216763, alsterpaullone and 1-azakenpaullone, on thapsigargin-induced apoptosis. These inhibitors completely protected cells from thapsigargin-induced apoptosis. In addition, GSK-3 inhibitors inhibited caspase-9 and caspase-3 activation accompanied by thapsigargin-induced apoptosis. These results suggest that thapsigargin induces caspase-dependent apoptosis mediated through GSK-3beta activation in rat cortical neurons.
Takadera
Tsuneo
T
Department of Clinical Chemistry, Faculty of Pharmaceutical Sciences, Hokuriku University, Kanazawa, Japan. t-takadera@hokuriku-u.ac.jp
Fujibayashi
Mineki
M
Kaniyu
Hisako
H
Sakota
Naho
N
Ohyashiki
Takao
T
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D020169:Caspases / Q000378:metabolism*; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology*; D016291:Dizocilpine Maleate; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000378:metabolism*; D018691:Excitatory Amino Acid Antagonists / Q000378:metabolism; D038362:Glycogen Synthase Kinase 3 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors; D019284:Thapsigargin / Q000378:metabolism*
D004791:Enzyme Inhibitors; D018691:Excitatory Amino Acid Antagonists; D016194:Receptors, N-Methyl-D-Aspartate; D019284:Thapsigargin; D016291:Dizocilpine Maleate; D038362:Glycogen Synthase Kinase 3; D020169:Caspases