TRANSCRIPTIONAL INDUCTION OF THE FATTY-ACID-BINDING PROTEIN GENE IN MOUSE-LIVER BY BEZAFIBRATE

The mechanism by which hypolipidemic peroxisome proliferators of the fibrate family induce the liver fatty acid binding protein in liver of rodents is unknown. In order to delineate the level at which this protein is induced, the transcriptional activity of the specific gene encoding for liver fatty acid binding protein was measured in isolated hepatocyte nuclei obtained from male Swiss mice daily force-fed during 7 days with 400 mg/kg body weight bezafibrate. This treatment induced a 4-fold increase in the liver fatty acid binding protein transcription rate. Liver fatty acid binding protein mRNA level, measured by Northern blot analysis and cytosolic content of this protein, analyzed by immunoblotting, increased concurrently. From these results we conclude that the increase in the cytosolic liver fatty acid binding protein level by bezafibrate is due to an enhancement of the transcription rate of the liver fatty acid binding protein gene. Whether the transcriptional effect is mediated by peroxisome proliferator-receptor remains to be elucidated.