Endurance training blocks uncoupling protein 1 up-regulation in brown adipose tissue while increasing uncoupling protein 3 in the muscle tissue of rats fed with a high-sugar diet.
The mitochondrial uncoupling proteins (UCPs) of interscapular brown adipose tissue (iBAT) and of muscles play important roles in energy balance. For instance, the expression of UCP1 and UCP3 are modulated by free fatty acid gradients induced by high-sugar diets and acute exercise that is dependent on sympathetic stimulation. However, the effects of endurance training in animals fed with high-sugar diets are unknown. This study aims to evaluate the long-term effects of diet and exercise on UCP1 and UCP3 levels and energy balance efficiency. Rats fed with standard or high-sugar (HSD) diets were simultaneously subjected to running training over an 8-week period. After the training period, the rats were decapitated, and the iBAT and gastrocnemius muscle tissues were removed for evaluation of the β₃-receptor, Ucp1, and Ucp3 mRNA and protein expression, which were analyzed by quantitative reverse transcriptase polymerase chain reaction and Western blot, respectively. Groups fed with an HSD displayed a higher adiposity index and iBAT weight (P < .05), whereas exhibited an up-regulation of Ucp1 mRNA and protein levels (P < .05). Training increased β₃-receptor mRNA in iBAT and reduced the Ucp3 mRNA in muscle tissues. In association with an HSD, training restored the increasing β₃-receptor mRNA and greatly up-regulated the levels of Ucp3 mRNA. Therefore, training blocked the HSD-induced up-regulation of UCP1 expression in iBAT, whereas it up-regulated the expression of Ucp3 mRNA in muscle. These results suggest that training enhances the relationship between Ucp1/Ucp3 mRNA levels, which could result in higher energy efficiency, but not when HSD-induced elevated sympathetic activity is maintained.
Departmento de Ciências Biológicas-NUPEB, Laboratório de Bioquímica e Biologia Molecular, ICEB-Universidade Federal de Ouro Preto, Ouro Preto, MG, Brazil.
Karina Barbosa
KB
de Queiroz
Gisele Vieira
GV
Rodovalho
Juliana Bohnen
JB
Guimarães
Daniel Carvalho
DC
de Lima
Cândido Celso
CC
Coimbra
Elísio Alberto
EA
Evangelista
Renata
R
Guerra-Sá
D002001:Adipose Tissue, Brown / Q000378:metabolism*; D000818:Animals; D015153:Blotting, Western; D001835:Body Weight; D002950:Citrate (si)-Synthase / Q000378:metabolism; D004032:Diet; D019422:Dietary Sucrose / Q000008:administration & dosage*; D002149:Energy Intake; D004734:Energy Metabolism; D007473:Ion Channels / Q000235:genetics / Q000378:metabolism*; D008297:Male; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000378:metabolism; D010807:Physical Endurance; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D000071246:Uncoupling Protein 2; D000071247:Uncoupling Protein 3; D015854:Up-Regulation
D019422:Dietary Sucrose; D007473:Ion Channels; D024101:Mitochondrial Proteins; D012333:RNA, Messenger; C000604394:Ucp3 protein, rat; D000071246:Uncoupling Protein 2; D000071247:Uncoupling Protein 3; D002950:Citrate (si)-Synthase