Korean J Physiol Pharmacol.  1999 Feb;3(1):19-28.

The mechanism of t-butylhydroperoxide-induced apoptosis in IMR-32 human neuroblastoma cells

• Kim JA
• Lee YS
• Huh K

Abstract

Apoptosis has been implicated in the pathophysiological mechanisms of various neurodegenerative diseases. In a variety of cell types, oxidative stress has been demonstrated to play an important role in the apoptotic cell death. However, the exact mechanism of oxidative stress-induced apoptosis in neuronal cells is not known. In this study, we induced oxidative stress in IMR-32 human neuroblastoma cells with tert-butylhydroperoxide (TBHP), which was confirmed by significantly reduced glutathione content and glutathione reductase activity, and increased glutathione peroxidase activity. TBHP induced decrease in cell viability and increase in DNA fragmentation, a hallmark of apoptosis, in a dose-dependent manner. TBHP also induced a sustained increase in intracellular Ca2+ concentration, which was completely prevented either by EGTA, an extracellular Ca2+ chelator or by flufenamic acid (FA), a non-selective cation channel (NSCC) blocker. These results indicate that the TBHP-induced intracellular Ca2+ increase may be due to Ca2+ influx through the activation of NSCCs. In addition, treatment with either an intracellular Ca2+ chelator (BAPTA/AM) or FA significantly suppressed the TBHP-induced apoptosis. Moreover, TBHP increased the expression of p53 gene but decreased c-myc gene expression. Taken together, these results suggest that the oxidative stress-induced apoptosis in neuronal cells may be mediated through the activation of intracellular Ca2+ signals and altered expression of p53 and c-myc.

Keyword

tert-butyl hydroperoxide; Oxidative stress; Apoptosis; IMR-32 cells; Intracellular Ca2+; p53; c-myc; bcl-2

MeSH Terms

Apoptosis*
Cell Death
Cell Survival
DNA Fragmentation
Egtazic Acid
Flufenamic Acid
Genes, myc
Genes, p53
Glutathione
Glutathione Peroxidase
Glutathione Reductase
Humans*
Neuroblastoma*
Neurodegenerative Diseases
Neurons
Oxidative Stress
tert-Butylhydroperoxide
Egtazic Acid
Flufenamic Acid
Glutathione
Glutathione Peroxidase
Glutathione Reductase
tert-Butylhydroperoxide