Induction of cardiac FABP gene expression by long chain fatty acids in cultured rat muscle cells

The induction of cardiac FABP expression by long-chain fatty acids was meas ured in cultured rat myoblasts, myotubes and adult cardiomyocytes. With qua ntitative RT-PCR techniques, the primary transcription product of the FABP gene and the mature mRNA were measured. Incubations of 30 min resulted in a larger than 2-fold increase of the primary transcript in all cells, and FA BP mRNA more than doubled in myoblasts and cardiomyocytes after 10 h of fat ty acid exposure. The results demonstrate that long chain fatty acids induc e the expression of the cardiac FABP gene in muscle cells and their undiffe rentiated precursors at the level of transcription initiation, suggesting t hat all factors involved in fatty acid dependent gene induction are already present in myoblasts. Thus, myoblast cell lines should be useful for the c haracterization of fatty acid response elements that control the expression of the FABP gene.