OBJECTIVE: To test the hypothesis that consumption of a high-fat diet leads to an increase in UCP mRNA expression in human skeletal muscle. In a group of endurance athletes, with a range in fiber type distribution, we hypothesized that the effect of the high-fat diet on UCP2 and UCP3 mRNA expression is more pronounced in muscle fibers which are known to have a high capacity to shift from carbohydrate to fat oxidation (type IIA fibers). DESIGN: Ten healthy trained athletes (five males, five females) consumed a low-fat diet (17+/-0.9 en% of fat) and high-fat diet (41.4+/-1.4 en% fat) for 4 weeks, separated by a 4 week wash-out period. Muscle biopsies were collected at the end of both dietary periods. MEASUREMENTS: Using RT-PCR, levels of UCP2 and UCP3 mRNA expression were measured and the percentage of type I, IIA and IIB fibers were determined using the myofibrillar ATPase method in all subjects. RESULTS: UCP3L mRNA expression tended to be higher on the high-fat diet, an effect which reached significance when only males were considered (P=0.037). Furthermore, diet-induced change in mRNA expression of UCP3T (r: 0.66, P=0.037), UCP3L (r: 0.61, P=0.06) and UCP2 (r: 0.70, P=0.025), but not UCP3S, correlated significantly with percentage dietary fat on the high-fat diet. Plasma FFA levels were not different during the two diets. Finally, the percentage of type IIA fibers was positively correlated with the diet-induced change in mRNA expression for UCP2 (r: 0.7, P=0.03), UCP3L (r: 0.73, P=0.016) and UCP3T (r: 0.68, P=0.03) but not with UCP3S (r: 0.06, NS). CONCLUSION: UCP2 and UCP3 mRNAs are upregulated by a high-fat diet. This upregulation is more pronounced in humans with high proportions of type IIA fibers, suggesting a role for UCPs in lipid utilization.
OBJECTIVE: To test the hypothesis that consumption of a high-fat diet leads to an increase in UCP mRNA expression in human skeletal muscle. In a group of endurance athletes, with a range in fiber type distribution, we hypothesized that the effect of the high-fat diet on UCP2 and UCP3 mRNA expression is more pronounced in muscle fibers which are known to have a high capacity to shift from carbohydrate to fat oxidation (type IIA fibers). DESIGN: Ten healthy trained athletes (five males, five females) consumed a low-fat diet (17+/-0.9 en% of fat) and high-fat diet (41.4+/-1.4 en% fat) for 4 weeks, separated by a 4 week wash-out period. Muscle biopsies were collected at the end of both dietary periods. MEASUREMENTS: Using RT-PCR, levels of UCP2 and UCP3 mRNA expression were measured and the percentage of type I, IIA and IIB fibers were determined using the myofibrillar ATPase method in all subjects. RESULTS: UCP3L mRNA expression tended to be higher on the high-fat diet, an effect which reached significance when only males were considered (P=0.037). Furthermore, diet-induced change in mRNA expression of UCP3T (r: 0.66, P=0.037), UCP3L (r: 0.61, P=0.06) and UCP2 (r: 0.70, P=0.025), but not UCP3S, correlated significantly with percentage dietary fat on the high-fat diet. Plasma FFA levels were not different during the two diets. Finally, the percentage of type IIA fibers was positively correlated with the diet-induced change in mRNA expression for UCP2 (r: 0.7, P=0.03), UCP3L (r: 0.73, P=0.016) and UCP3T (r: 0.68, P=0.03) but not with UCP3S (r: 0.06, NS). CONCLUSION:UCP2 and UCP3 mRNAs are upregulated by a high-fat diet. This upregulation is more pronounced in humans with high proportions of type IIA fibers, suggesting a role for UCPs in lipid utilization.
Authors: N M Fisher; K Meksawan; A Limprasertkul; P J Isackson; D R Pendergast; G D Vladutiu Journal: J Inherit Metab Dis Date: 2007-04-05 Impact factor: 4.982
Authors: Matthijs K C Hesselink; Paul L Greenhaff; Dimitru Constantin-Teodosiu; Eric Hultman; Wim H M Saris; Robby Nieuwlaat; Gert Schaart; Esther Kornips; Patrick Schrauwen Journal: J Clin Invest Date: 2003-02 Impact factor: 14.808
Authors: C V Musa; A Mancini; A Alfieri; G Labruna; G Valerio; A Franzese; F Pasanisi; M R Licenziati; L Sacchetti; P Buono Journal: Int J Obes (Lond) Date: 2011-04-19 Impact factor: 5.095
Authors: Heiko Bugger; Sihem Boudina; Xiao Xuan Hu; Joseph Tuinei; Vlad G Zaha; Heather A Theobald; Ui Jeong Yun; Alfred P McQueen; Benjamin Wayment; Sheldon E Litwin; E Dale Abel Journal: Diabetes Date: 2008-08-04 Impact factor: 9.461