Up-regulation of SREBP-1c and lipogenic genes in skeletal muscles after exercise training.
Exercise increases utilization of lipids and carbohydrates in skeletal muscles. After exercise, replenishment of glycogen and triglyceride occurs in skeletal muscles. To elucidate the mechanism of lipid filling effect after exercise training, expression patterns of genes related to triglyceride synthesis were examined under several exercise conditions. Mice exercised by 2-week swimming had 1.4-2.0-fold increases of sterol regulatory element-binding protein 1 (SREBP-1) mRNA in skeletal muscles after the last swimming, with increases of lipogenic genes, such as acetyl-CoA carboxylase-1 (ACC-1), stearoyl-CoA desaturase-1 (SCD-1), and acyl CoA:diacylglycerol acyltransferase-1 (DGAT-1) mRNAs. An increase of SREBP-1 mRNA was observed after the 6-h treadmill running training but not after 1-h single treadmill running. Increase of SREBP-1 mRNA was due to the increase of SREBP-1c isoform but not of SREBP-1a. These data indicate that SREBP-1c, a key transcription factor of liver triglyceride synthesis, might also be responsible for skeletal muscle triglyceride synthesis after chronic exercise training.
Ikeda
Shinobu
S
Division of Clinical Nutrition, National Institute of Health and Nutrition, 1-23-1 Toyama, Shinjuku-ku, Tokyo, Japan.
Miyazaki
Hiromi
H
Nakatani
Teruyo
T
Kai
Yuko
Y
Kamei
Yasutomi
Y
Miura
Shinji
S
Tsuboyama-Kasaoka
Nobuyo
N
Ezaki
Osamu
O
D000103:Acetyl-CoA Carboxylase / Q000235:genetics / Q000378:metabolism; D042964:Acyl-CoA Dehydrogenase; D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism; D000818:Animals; D022762:CCAAT-Enhancer-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D051048:Diacylglycerol O-Acyltransferase; D005080:Exercise Test; D044943:Fatty Acid Desaturases / Q000235:genetics / Q000378:metabolism; D005260:Female; D051275:Glucose Transporter Type 4; D008099:Liver / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009004:Monosaccharide Transport Proteins / Q000235:genetics / Q000378:metabolism; D009124:Muscle Proteins; D018482:Muscle, Skeletal / Q000502:physiology*; D010805:Physical Conditioning, Animal; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D013230:Stearoyl-CoA Desaturase / Q000235:genetics / Q000378:metabolism; D051780:Sterol Regulatory Element Binding Protein 1; D013550:Swimming; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014280:Triglycerides / Q000378:metabolism*; D015854:Up-Regulation / Q000502:physiology*
D022762:CCAAT-Enhancer-Binding Proteins; D004268:DNA-Binding Proteins; D051275:Glucose Transporter Type 4; D009004:Monosaccharide Transport Proteins; D009124:Muscle Proteins; D018160:Receptors, Cytoplasmic and Nuclear; C495693:Slc2a4 protein, mouse; C497388:Srebf1 protein, mouse; D051780:Sterol Regulatory Element Binding Protein 1; D014157:Transcription Factors; D014280:Triglycerides; D044943:Fatty Acid Desaturases; D013230:Stearoyl-CoA Desaturase; D042964:Acyl-CoA Dehydrogenase; D000217:Acyltransferases; C494882:Dgat1 protein, mouse; D051048:Diacylglycerol O-Acyltransferase; D000103:Acetyl-CoA Carboxylase