title: Are exercise-induced genes induced by exercise?
abstract: Numerous human in vivo studies on skeletal muscle gene expression have investigated the effects of given interventions. These have been founded on the assumption that presampling can be regarded as a representative control for postintervention sampling. However, many genes are responsive to the metabolic status, which varies during the day, so that observed differences in gene expression between the pre- and post-sample may therefore be a result of the daily variations rather than an intervention. Furthermore, the sampling itself can cause a local stress response, which may also influence the expression of some genes in later samples from the same localized area. To test this, we performed a short-term human endurance exercise study in which muscle biopsies were obtained from healthy untrained individuals (n=14) before and in the hours after exercise to measure the expression of mRNA for previously reported exercise-related genes (e.g., PPARgamma coactivator-1alpha (PGC-1alpha), pyruvate dehydrogenase kinase 4 (PDK4), MyoD, p21, (heat shock protein 72 (HSP72), lipoprotein lipase (LPL), citrate synthase (CS), and glucose transporter 4 (GLUT4)). To test for changes unrelated to exercise, one half of the subjects did not exercise. As suspected, several presumed exercise-induced genes were induced even without the exercise. Our data demonstrate that presampling is not always a representative control for postintervention sampling, illustrating that use of presampling can cause erroneous interpretations of the underlying induction signals.
authors.affiliation: Department of Molecular Muscle Biology, Copenhagen Muscle Research Centre, Rigshospitalet, Copenhagen, Denmark.
authors.forename: Kristian
authors.initials: K
authors.lastname: Vissing
authors.forename: Jesper L
authors.initials: JL
authors.lastname: Andersen
authors.forename: Peter
authors.initials: P
authors.lastname: Schjerling
mesh_terms: D000328:Adult; D002950:Citrate (si)-Synthase / Q000235:genetics; D015444:Exercise / Q000502:physiology*; D005786:Gene Expression Regulation / Q000502:physiology*; D018816:Genes, cdc / Q000502:physiology; D051275:Glucose Transporter Type 4; D050884:HSP72 Heat-Shock Proteins; D006360:Heat-Shock Proteins / Q000235:genetics; D006801:Humans; D008071:Lipoprotein Lipase / Q000235:genetics; D008297:Male; D009004:Monosaccharide Transport Proteins / Q000235:genetics; D009124:Muscle Proteins / Q000235:genetics; D018482:Muscle, Skeletal / Q000737:chemistry / Q000378:metabolism; D017570:MyoD Protein / Q000235:genetics; D018008:Myogenin / Q000235:genetics; D018384:Oxidative Stress; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D011494:Protein Kinases / Q000235:genetics; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics
chemical_list: D051275:Glucose Transporter Type 4; D050884:HSP72 Heat-Shock Proteins; D006360:Heat-Shock Proteins; C503799:MYOG protein, human; D009004:Monosaccharide Transport Proteins; D009124:Muscle Proteins; D017570:MyoD Protein; D018008:Myogenin; C486497:PPARGC1A protein, human; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; C495692:SLC2A4 protein, human; D014157:Transcription Factors; D002950:Citrate (si)-Synthase; D011494:Protein Kinases; C403287:pyruvate dehydrogenase kinase 4; D008071:Lipoprotein Lipase; C501009:HRAS protein, human; D016283:Proto-Oncogene Proteins p21(ras)