Comparative studies on the effects of high-fat diet, endurance training and obesity on Ucp1 expression in male C57BL/6 mice

Abstract

Background: Obesity triggers a variety of severe conditions, therefore deteriorates metabolism rate of adipose tissues and muscles. Uncoupling proteins which are highly stimulated by fatty acids are potential targets for anti-obesity agents through breaking the electron gradient in the mitochondrial matrix and creating imbalances in the electron transport chain, thereby increasing the amount of substrate used to produce energy. Therefore, the aim of present study is assessment of exercise and high fat diet on expression level of Ucp1 subcutaneous white and brown adipose tissues (scWAT & BAT) respectively. Methods: To perform experiments, 48 male C57BL/6 mice were divided to two major groups and fed with high fat diet (HFD) or low fat diet (LFD) during a period of 12 weeks. After the first intervention, each groups was divided into four groups randomly as (HF-EX), (HF-SED), (LF-EX), (LF-SED) [EX: exercise; SED: sedentary] in form of treadmill running for 45 min/day, 5 days/week during 8 weeks. One day after the last practice session, mice were sacrificed and Ucp1 expression was assessed on scWAT & BAT. Results: Data indicated a down-regulation in scWAT Ucp1 in obese mice similar to what observed for the expression of Pgc1α. Both, BAT Ucp1 and Pgc1α mRNA decreased significantly in response to obesity and physical activity. Moreover, exercise caused significant decrease in scWAT mitochondrial proteins contradictory to BAT. Conclusion: Taken together, exercise exerted controversial effects compared with HFD and obesity on expression of Ucp1 and Pgc1α in scWAT dissimilar to BAT tissues, concluding that obesity may cause a resistance to exercise in terms of metabolic demands for scWAT tissue. © 2018