Genome-wide analysis of PPAR activation in murine small intestine

The peroxisome proliferator-activated receptor alpha (PPAR) is a fatty acid-activated transcription factor that governs a variety of biological processes. Little is known about the role of PPAR in the small intestine. Since this organ is frequently exposed to high levels of PPAR ligands via the diet, we set out to characterize the function of PPAR in small intestine using functional genomics experiments and bioinformatics tools. PPAR was expressed at high levels in both human and murine small intestine. Detailed analyses showed that PPAR was expressed most highly in villus cells of proximal jeju-num. Microarray analyses of total tissue samples revealed, that in addition to genes involved in fatty acid and triacylglycerol metabo-lism, transcription factors and enzymes connected to sterol and bile acid metabolism, including FXR and SREBP1, were specifically induced. In contrast, genes involved in cell cycle and differentiation, apoptosis, and host defense were repressed by PPAR activation