Submitted on October 14, 2008
Revised on December 11, 2008
Accepted on December 11, 2008
Isolation stress for 30 days alters hepatic gene expression profiles, especially with reference to lipid metabolism in mice
Keiko Motoyama1, Yuji Nakai2, Tomoya Miyashita1, Yuichiro Fukui3, Maki Morita1, Kazutsuka Sanmiya4, Hiroyuki Sakakibara1, Ichiro Matsumoto4, Keiko Abe4, Takafumi Yakabe3, Nobuhiro Yajima3, and Kayoko Shimoi1*
1 University of Shizuoka
2 The University of Tokyo
3 Kagome Co. Ltd.
4 University of Tokyo
* To whom correspondence should be addressed. E-mail: shimoi{at}u-shizuoka-ken.ac.jp.
To elucidate the physiological responses to a social stressor, we exposed mice to an isolation stress and analyzed their hepatic gene expression profiles using a DNA microarray. Male BALB/c mice were exposed to isolation stress for 30 days, and then hepatic RNA was sampled and subjected to DNA microarray analysis. The isolation stress altered the expression of 420 genes (after considering the false discovery rate). Gene Ontology analysis of these differentially expressed genes indicated that the stress remarkably down-regulated the lipid metabolism-related pathway through peroxisome proliferator activated receptor alpha, while the lipid biosynthesis pathway controlled by sterol regulatory element binding factor 1, Golgi vesicle transport and secretory pathway-related genes were significantly up-regulated. These results suggest that isolation for 30 days with a mild and consecutive social stress regulates the systems for lipid metabolism and also causes endoplasmic reticulum stress in mouse liver.
