Effects of caffeine on the uncoupling protein family in obese yellow KK mice.
1. The hypothesis that caffeine upregulates uncoupling protein (UCP)-1, UCP-2 and UCP-3 expression, which contribute to thermogenesis, was investigated in obese mice. 2. The mRNA levels of UCP-1, -2 and -3 in brown adipose tissue (BAT), UCP-2 in white adipose tissue (WAT), and UCP-2 and -3 in skeletal muscle were measured using real-time quantitative reverse transcription-polymerase chain reaction analysis in obese yellow KK mice 4 h after the subcutaneous administration of either 60 mg/kg caffeine or physiological saline. Plasma free fatty acids, adrenaline, noradrenaline and dopamine levels were also measured. 3. In caffeine-injected obese mice, UCP-1 mRNA levels were significantly increased by 1.5-fold in BAT, UCP-2 mRNA levels were increased by 1.8- and 2.5-fold in BAT and skeletal muscles, respectively, and UCP-3 mRNA levels were increased 1.7- and 3.4-fold in BAT and skeletal muscles, respectively, compared with control mice injected with physiological saline. There was no difference in UCP-2 mRNA levels in WAT between the two groups. 4. Plasma free fatty acids and adrenaline levels were significantly elevated in mice treated with caffeine compared with those injected with physiological saline. 5. It was concluded that caffeine upregulates the expression of UCP-1, UCP-2 and UCP-3 in BAT and UCP-2 and UCP-3 in skeletal muscles, which may contribute to thermogenesis in obese mice.
Kogure
Akinori
A
First Department of Internal Medicine, Kyoto Prefectural University of Medicine, Kyoto, Japan. akogure@koto.kpu-m.ac.jp
Sakane
Naoki
N
Takakura
Yasuto
Y
Umekawa
Tsunekazu
T
Yoshioka
Keiji
K
Nishino
Hoyoku
H
Yamamoto
Takayuki
T
Kawada
Teruo
T
Yoshikawa
Toshikazu
T
Yoshida
Toshihide
T
D000273:Adipose Tissue / Q000378:metabolism; D000818:Animals; D002110:Caffeine / Q000494:pharmacology*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D006943:Hyperglycemia / Q000150:complications / Q000378:metabolism; D006946:Hyperinsulinism / Q000150:complications / Q000378:metabolism; D007473:Ion Channels; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D026901:Membrane Transport Proteins; D051379:Mice; D008820:Mice, Obese; D024101:Mitochondrial Proteins; D018482:Muscle, Skeletal / Q000378:metabolism; D009765:Obesity / Q000378:metabolism*; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000071256:Uncoupling Protein 1; D000071246:Uncoupling Protein 2; D000071247:Uncoupling Protein 3; D015854:Up-Regulation
D002352:Carrier Proteins; D007473:Ion Channels; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D024101:Mitochondrial Proteins; D011506:Proteins; D012333:RNA, Messenger; C000604372:Ucp1 protein, mouse; C000604390:Ucp2 protein, mouse; C000604393:Ucp3 protein, mouse; D000071256:Uncoupling Protein 1; D000071246:Uncoupling Protein 2; D000071247:Uncoupling Protein 3; D002110:Caffeine