Transcriptional regulation of the fatty acid binding protein 2 (FABP2) gene by the hepatic nuclear factor 1 alpha (HNF-1alpha).

The human fatty acid binding protein (FABP2) is involved in intestinal absorption and intracellular trafficking of long-chain fatty acids. Here we investigate transcriptional regulation of FABP2 by the endodermal hepatic nuclear factor 1 alpha (HNF-1alpha). In electromobility shift and supershift assays we show the presence of two adjacent HNF-1alpha binding sites within the FABP2 promoter regions -185 to -165 and -169 to -149. HNF-1alpha activates an FABP2 promoter luciferase construct by 3.5 and 20-fold in Caco-2 and Hela cells, respectively. Mutational analysis of HNF-1alpha elements resulted in about 50% reduction of basal and HNF-1alpha induced activity of FABP2 promoter constructs, predominantly caused by deletion of the -185 to -165 site. Thus, our data suggest a major role of HNF-1alpha in control of FABP2 expression in intestine via a functional HNF-1alpha recognition element within FABP2 promoter region -185 to -165.