Tissue-dependent upregulation of rat uncoupling protein-2 expression in response to fasting or cold.
The control of uncoupling protein-2 (UCP2) mRNA expression in rat brown adipose tissue (BAT), heart and skeletal muscles was examined. Cold exposure (48 h) increased UCP2 mRNA in BAT, heart and soleus muscle by 2.4-, 4.3- and 2.6-fold, respectively. Fasting (48 h) had no effect on UCP2 mRNA expression neither in BAT nor in heart, but markedly increased it in skeletal muscles. While the upregulation of UCP2 mRNA in response to cold exposure is in line with a putative uncoupling role for this protein in thermoregulatory thermogenesis, the unexpected upregulation of UCP2 in skeletal muscles in response to fasting seems inconsistent with its role as an uncoupling protein involved in dietary regulation of thermogenesis.
Boss
O
O
Department of Medical Biochemistry, Faculty of Medicine, University of Geneva, Switzerland. Olivier.Boss@medecine.unige.ch
Samec
S
S
Dulloo
A
A
Seydoux
J
J
Muzzin
P
P
Giacobino
J P
JP
D002001:Adipose Tissue, Brown / Q000378:metabolism; D000818:Animals; D001833:Body Temperature Regulation; D003080:Cold Temperature; D005215:Fasting; D005786:Gene Expression Regulation; D007473:Ion Channels; D008297:Male; D026901:Membrane Transport Proteins; D024101:Mitochondrial Proteins; D008969:Molecular Sequence Data; D018482:Muscle, Skeletal / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism; D011506:Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D000071246:Uncoupling Protein 2
D007473:Ion Channels; D026901:Membrane Transport Proteins; D024101:Mitochondrial Proteins; D011506:Proteins; D012333:RNA, Messenger; C000604391:Ucp2 protein, rat; D000071246:Uncoupling Protein 2