Activation of peroxisome proliferator-activated receptor-α (PPARα) in proximal intestine improves postprandial lipidemia in obese diabetic KK-Ay mice

Abstract

Postprandial lipidemia is a risk factor for cardiovascular diseases. Thus, the suppression of postprandial lipidemia is valuable for disease management. Peroxisome proliferator-activated receptor- (PPAR ) is a key regulator in the lipid metabolism of peripheral tissues such as the liver and skeletal muscle, whose activation enhances fatty acid oxidation and decreases circulating lipid level. Recently, we have shown that bezafibrate, an agonistic compound for PPAR , suppresses post-prandial lipidemia by enhancing fatty acid oxidation in intestinal epithelial cells under physiological conditions. However, it was not elucidated whether the effect of PPAR on postprandial lipidemia is also observed under obese conditions, which change lipid metabolisms in various tissues and cells. Here, we observed that bezafibrate enhanced fatty acid oxidation in intestinal epithelial cells of obese diabetic KK-Ay mice. Bezafibrate treatment increased the mRNA expression levels of fatty acid oxidation-related genes, which are targets of PPAR , and enhanced CO2 production from [14C]-palmitic acid. The bezafibrate-treated mice showed the suppression of increasing serum triacylglyceride level after the oral administration of olive oil. Moreover, the effects of bezafibrate on mRNA expression and fatty acid oxidation were shown in only the proximal intestinal epithelial cells. These findings indicate that PPAR activation suppresses postprandial lipidemia under obese conditions through the enhancement of fatty acid oxidation, and that only the proximal intestine con-tributes to the effects in mice, suggesting that intestinal PPAR can be a target for prevention of obese-induced postprandial lipidemia.