Identification of Regulation Networks of Lipid Metabolism by Nuclear Receptors

Nuclear receptors form a superfamily of proteins that function as ligand-activated transcription factors. Recently ligands for orphan receptors such as liver X receptor (LXR), farnesoid X receptor (FXR), and peroxisome proliferator-activated receptor (PPAR) have been identified, and they were found to act as metabolic sensors. Target genes of these nuclear receptors include lipid metabolic enzymes, transporters, and also nuclear receptors themselves, so that these gene products metabolize and transport ligands themselves (Fig. 1). Therefore, identifying the target genes will be guidance to elucidate complex regulation networks. In this study, we have tried to identify the target genes and the related networks combining bibliographic knowledge and algorithmic elucidation.