222-LB: Switching Palmitoyl and Oleoyl Position in Sn-2 and Sn-3 of a Triacylglycerol Led to Differential Body Weight Gain Rates and Hepatic Gene Expressions in Mice Fed a High-Fat Diet

Alterations of fatty acid metabolism have been associated with diabetes. Triacylglycerol (TAG) can be obtained from dietary sources and synthesized de novo. The composition and location of the fatty acyl groups in a TAG can affect its physicochemical features such as melting temperature, and physiological characteristics such as digestion, absorption, and lipid metabolism. We hypothesize that the TAG fatty acyl position affects the body weight gain and lipid metabolism of mice in a high-fat diet (HFD) setting. Twenty-seven 6-week-old male C57/BL6J mice were randomly assigned to 3 dietary treatment groups, 1,2-dipalmitoyl-3-oleoylglycerol (PPO, 36 % w/w diet) , 1,3-dipalmitoyl-2-oleoylglycerol (POP, 36% w/w diet) , and the chow diet control groups. Mice in each group were fed their respective diet for 6 weeks, and food intake and body weight were measured daily. Mice fed the PPO diet had significantly higher food intake, calories intake and body wight gain rate, and lower liver to body weight ratio than those fed the POP diet. Mice fed the chow diet had significantly higher total grams of food intake, but lower calories intake, liver and epididymal fat weight, and body weight gain rate than those fed the PPO, but not the POP, diet. Mice in the PPO group had significantly higher serum glucose than that in other two groups, whereas mice fed the chow diet had significantly lower plasma cholesterol level than those HFD groups. The plasma TAG levels were not different among them. The hepatic levels of insulin receptor substrate 1, and fatty acid synthase, and phosphorylated acetyl CoA carboxylase in mice fed the chow diet are significantly higher than those fed the PPO or POP diet, whereas the hepatic expression level of stearoyl CoA desaturase 1 in mice fed the POP diet was lower than those fed the PPO or chow diet. We conclude that feeding a HFD affects the expression levels of hepatic proteins for lipid metabolism in mice. In addition, the position of fatty acyl group in a TAG affects the food intake, the body weight gain rate and lipid homeostasis in mice. Disclosure X. Hu: None. T. Wang: None. G. Chen: None.