1. Selenium protects the hypoxia induced apoptosis in neuroblastoma cells through upregulation of Bcl-2.
- Author
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Sarada SK, Himadri P, Ruma D, Sharma SK, Pauline T, and Mrinalini
- Subjects
- Animals, Antioxidants pharmacology, Apoptosis physiology, Cell Line, Tumor, DNA Fragmentation drug effects, Free Radicals metabolism, Glutathione metabolism, Hypoxia, Brain metabolism, Hypoxia, Brain physiopathology, Hypoxia-Inducible Factor 1, alpha Subunit drug effects, Hypoxia-Inducible Factor 1, alpha Subunit metabolism, Mice, Nerve Degeneration metabolism, Nerve Degeneration physiopathology, Neuroblastoma, Oxidative Stress physiology, Proto-Oncogene Proteins c-bcl-2 metabolism, Superoxide Dismutase drug effects, Superoxide Dismutase metabolism, Up-Regulation drug effects, Up-Regulation physiology, Apoptosis drug effects, Hypoxia, Brain drug therapy, Nerve Degeneration drug therapy, Oxidative Stress drug effects, Proto-Oncogene Proteins c-bcl-2 drug effects, Selenium pharmacology
- Abstract
Selenium (Se) is an essential micronutrient as well as a toxic trace element in animal and human nutrition. The effects of Se in the immune system and some diseases are well documented. The objective of the present study was to examine the role of Se in reducing the hypoxia induced apoptosis in neuroblastoma cell line. Hypoxia showed an enhanced cytotoxicity, increased free radical production and apoptosis (p<0.001) which was measured in terms of DNA break down by comet assay. Hypoxia has decreased reduced Glutathione (GSH) content, Glutathione Reductase (GR), Glutathione peroxidase (GPx) and Superoxide Dismutase (SOD) activities as compared to control cells. During hypoxic condition the expression of cytochrome C, pro and active caspase-3 levels were enhanced significantly followed by nonsignificant upregulation of Bcl-2. But, the Se supplementation inhibited the cytotoxicity, free radical generation and stabilized the HIF-1alpha accumulation in cells under hypoxia. The GSH content, GR, GPx and SOD activities increased significantly in Se-treated hypoxic cells, as compared to control. Further there was an appreciable inhibition of apoptosis by upregulation of Bcl-2 proteins, in the presence of Se under hypoxia. Selenium supplementation to cells significantly inhibited the hypoxia induced DNA fragmentation and restored the antioxidant status back to control levels. This study suggests that Se supplementation prevented the cells from hypoxia induced apoptosis by triggering upregulation of Bcl-2 protein and reducing the oxidative stress.
- Published
- 2008
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