International Journal of Biological Sciences

Impact factor

ISSN 1449-2288

News feeds of IJBS published articles
Manuscript login

open access Global reach, higher impact

Journal of Genomics in PubMed Central. Submit manuscript now...


International Journal of Medical Sciences

Journal of Cancer

Journal of Genomics


Journal of Bone and Joint Infection (JBJI)


Journal of Biomedicine

PubMed Central Indexed in Journal Impact Factor

Int J Biol Sci 2007; 3(5):335-341. doi:10.7150/ijbs.3.335

Research Paper

The responses of HT22 cells to the blockade of mitochondrial complexes and potential protective effect of selenium supplementation

Jun Panee1, Wanyu Liu1, Kyoko Nakamura2, Marla J. Berry1

1. Department of Cell & Molecular Biology, John A Burns Medical School, University of Hawaii, Honolulu HI 96813, USA
2. School of Medicine, Juntendo University, 2-1-1, Hongo, Bunkyo-ku, Tokyo 113-8421, Japan


Mitochondria are the major reactive oxygen species (ROS) – generating sites in mammalian cells. Blockade of complexes in the electron transport chain (ETC) increases the leakage of single electrons to O2 and therefore increases ROS levels. Complexes I and III have been reported to be the major ROS-generating sites in mitochondria. In this study, using mouse hippocampal HT22 cells as in vitro model, we monitored the change of intracellular ROS level in response to the blockade of ETC at different complex, and measured changes of gene expression of antioxidant enzymes and phase II enzymes, also evaluated potential protective effect of selenium (Se) supplementation to the cells under this oxidative stress. In summary, our results showed that complex I was the major ROS-generating site in HT22 cells. Complex I blockade upregulated the mRNA levels of glutamylcysteine synthetase heavy and light chains, glutathione-S-transferases omega1 and alpha 2, hemoxygenase 1, thioredoxin reductase 1, and selenoprotein H. Unexpectedly, the expression of the enzymes that directly scavenge ROS decreased, including superoxide dismutases 1 and 2, glutathione peroxidase 1, and catalase. Se supplementation increased glutathione levels and glutathione peroxidase activity, indicating a potential protective role in oxidative stress caused by ETC blockade.

Keywords: electron transport chain, complex I, rotenone, ROS, antioxidant

This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY-NC) License. See for full terms and conditions.
How to cite this article:
Panee J, Liu W, Nakamura K, Berry MJ. The responses of HT22 cells to the blockade of mitochondrial complexes and potential protective effect of selenium supplementation. Int J Biol Sci 2007; 3(5):335-341. doi:10.7150/ijbs.3.335. Available from