Docosahexaenoic acid regulates 5′ AMP‐activated protein kinase in adipocytes

Abstract

Docosahexaenoic acid (DHA) promotes lipolysis in animal livers and decreases the incidence of metabolic syndrome in human. Feeding weaning pigs diets with 2% soybean oil, beef tallow or DHA oil for 1 month to measure the effect of dietary oils on body weight and gene expression related to lipid metabolism, we found pig body weights were not affected by different dietary treatments, but the triglyceride concentration in plasma was reduced by the DHA treatment. The protein level of 5′ AMP‐activated protein kinase (AMPK) was significant decreased by the DHA treatment when compared to the beef tallow treatment (p <0.05). However, the hormone sensitive lipase (HSL), a lipolytic enzyme and phosphoenolypyruvate carboxykinase (PEPCK), an enzyme for glyceroneogenesis, were not affected by dietary oils. To investigate the acute effect of DHA on the expression of genes related to lipid, we induced preadipocyte 3T3‐L1 to adipocytes, and treated with or without 100 μM DHA for 15, 30 and 60 min. The gene expression of peroxisome proliferator activated receptor γ (PPARγ), adiponectin, adiponectin receptor 1, AMPK and PEPCK was not affected by the DHA treatment. Fatty acid synthase (FAS) was significantly increased (p <0.05). The data suggest that DHA may increase the expression of AMPK to affect its downstream gene function in order to midify cellular physiology. This observation gives a good hint to study whether DHA can affect cellular function through AMPK pathway.Grant Funding Source : National Scince Council