LAUSR

RE1-silencing transcription factor (REST) is a transcriptional factor which negatively regulates the expression of numerous neuronal genes. In this study, model mice lacking REST in adipocytes were generated to investigate the role of REST in adipocytes. This was achieved by mating Rest2lox/2lox mice with Adipoq-Cre mice, and the resultant Adipoq-Cre/Rest2lox/2lox mice were compared with Adipoq-Cre mice. Adipoq-Cre/Rest2lox/2lox mice exceeding 10 weeks of age showed increased body weight, fat mass, and adipocyte size; however no difference was observed in food intake. Glucose tolerance deteriorated under a high fat diet, but not under normal diets in Adipoq-Cre/Rest2lox/2lox mice. Oxygen consumption decreased in Adipoq-Cre/Rest2lox/2lox mice. The characteristics of gene expression in epididymal fat, i.e., white adipose tissue (WAT) and brown adipose tissue (BAT), isolated from Adipoq-Cre/Rest2lox/2lox mice, were compared by microarray with those from Adipoq-Cre mice. Although expression of numerous neuronal genes increased in Adipoq-Cre/Rest2lox/2lox mice, there were no differences in adipocyte-specific genes. Gene analyses utilizing a cluster one program detected a significant decrease in the mitochondrial translation gene group in WAT, but not BAT. There was no difference in the amount of mitochondrial DNA, whereas the expression of cytochrome C protein was reduced in WAT but not BAT, which was isolated from Adipoq-Cre/Rest2lox/2lox mice. These results indicate that obesity in Adipoq-Cre/Rest2lox/2lox mice is due to a mitochondrial dysfunction in WAT. It is also suggested that REST might regulate the mitochondrial function in WAT. Disclosure M. Fuwa: None. K. Kajita: None. K. Taguchi: None. T. Ikeda: None. T. Ishizuka: None. H. Morita: None.