Regulation of skeletal muscle UCP-2 and UCP-3 gene expression by exercise and denervation.
The factors that regulate gene expression of uncoupling proteins 2 and 3 (UCP-2 and UCP-3) in skeletal muscle are poorly understood, but both genes are clearly responsive to the metabolic state of the organism. Therefore, we tested the hypothesis that denervation and acute and/or chronic exercise (factors that profoundly affect metabolism) would alter UCP-2 and UCP-3 gene expression. For the denervation studies, the sciatic nerve of rat and mouse hindlimb was sectioned in one leg while the contralateral limb served as control. Northern blot analysis revealed that denervation was associated with a 331% increase (P < 0.001) in UCP-3 mRNA and a 200% increase (P < 0. 01) in UCP-2 mRNA levels in rat mixed gastrocnemius (MG) muscle. In contrast, denervation caused a 53% decrease (P < 0.001) in UCP-3 and a 63% increase (P < 0.01) in UCP-2 mRNA levels in mouse MG. After acute exercise (2-h treadmill running), rat UCP-3 mRNA levels were elevated (vs. sedentary control) 252% (P < 0.0001) in white gastrocnemius and 63% (P < 0.05) in red gastrocnemius muscles, whereas UCP-2 levels were unaffected. To a lesser extent, elevations in UCP-3 mRNA (22%; P < 0.01) and UCP-2 mRNA (55%; P < 0.01) levels were observed after acute exercise in the mouse MG. There were no changes in either UCP-2 or UCP-3 mRNA levels after chronic exercise (9 wk of wheel running). These results indicate that acute exercise and denervation regulate gene expression of skeletal muscle UCPs.
Cortright
R N
RN
Department of Biochemistry, East Carolina University School of Medicine, Greenville, North Carolina 27858-4354, USA.
Zheng
D
D
Jones
J P
JP
Fluckey
J D
JD
DiCarlo
S E
SE
Grujic
D
D
Lowell
B B
BB
Dohm
G L
GL
D000818:Animals; D015152:Blotting, Northern; D002352:Carrier Proteins / Q000235:genetics*; D005260:Female; D005786:Gene Expression Regulation / Q000502:physiology*; D006614:Hindlimb; D007473:Ion Channels; D008297:Male; D026901:Membrane Transport Proteins; D051379:Mice; D008810:Mice, Inbred C57BL; D024101:Mitochondrial Proteins; D009043:Motor Activity / Q000502:physiology*; D009121:Muscle Denervation; D018482:Muscle, Skeletal / Q000378:metabolism / Q000502:physiology*; D011506:Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D000071246:Uncoupling Protein 2; D000071247:Uncoupling Protein 3
D002352:Carrier Proteins; D007473:Ion Channels; D026901:Membrane Transport Proteins; D024101:Mitochondrial Proteins; D011506:Proteins; D012333:RNA, Messenger; C000604390:Ucp2 protein, mouse; C000604391:Ucp2 protein, rat; C000604393:Ucp3 protein, mouse; C000604394:Ucp3 protein, rat; D000071246:Uncoupling Protein 2; D000071247:Uncoupling Protein 3