The mechanism of t-butylhydroperoxide-induced apoptosis in IMR-32 human neuroblastoma cells.
- Author:
Jung Ae KIM
1
;
Yong Soo LEE
;
Keun HUH
Author Information
1. Department of Pharmacology, College of Pharmacy, Yeungnam University, Kyongsan, 712-749 South Korea.
- Publication Type:Original Article
- Keywords:
tert-butyl hydroperoxide;
Oxidative stress;
Apoptosis;
IMR-32 cells;
Intracellular Ca2+;
p53;
c-myc;
bcl-2
- MeSH:
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
- From:The Korean Journal of Physiology and Pharmacology
1999;3(1):19-28
- CountryRepublic of Korea
- Language:English
-
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.
