Liver and intestinal fatty acid binding proteins in control and TGFβ1 gene targeted deficient mice

The effect of transforming growth factor beta-1 (TGFβ1) expression on fatty acid binding proteins was examined in control and two strains of gene targeted TGFβ1-deficient mice. Homozygous TGFβ1-deficient 129 x CF-1, expressing multifocal inflammatory syndrome, had 25% less liver fatty acid binding protein (L-FABP) when compared to control mice. The decrease in L-FABP expression was not due to multifocal inflammatory syndrome since homozygous TGFβ1-deficient/immunodeficient C3H mice on a SCID background had 36% lower liver L-FABP than controls. This effect was developmentally related and specific to liver, but not the proximal intestine, where L-FABP is also expressed. Finally, the proximal intestine also expresses intestinal-FABP (I-FABP) which decreased 3-fold in the TGFβ1-deficient/immunodeficient C3H mice only. Thus, TGFβ1 appears to regulate the expression of L-FABP and I-FABP in the liver and the proximal intestine, respectively.