Gene expression of PPARgamma and PGC-1alpha in human omental and subcutaneous adipose tissues is related to insulin resistance markers and mediates beneficial effects of physical training.
OBJECTIVE
Obesity and type 2 diabetes (T2D) are reaching epidemic proportions in Western societies, and they contribute to substantial morbidity and mortality. The peroxisome proliferator-activated receptor gamma (PPARgamma) and PPARgamma coactivator-1alpha (PGC-1alpha) system plays an important role in the regulation of efficient energy utilization and oxidative phosphorylation, both of which are decreased in obesity and insulin resistance.


METHODS
We measured the metabolic parameters and the expression of PPARgamma and PGC-1alpha mRNA using quantitative real-time PCR in omental and subcutaneous (SC) adipose tissues in an observational study of 153 individuals as well as in SC fat and skeletal muscle in an interventional study of 60 subjects (20 each with normal glucose tolerance, impaired glucose tolerance, and T2D) before and after intensive physical training for 4 weeks.


RESULTS
PPARgamma and PGC-1alpha mRNA expression in both fat depots as well as in skeletal muscle is associated with markers of insulin resistance and cardiovascular risk. PGC-1alpha mRNA expression is significantly higher in SC fat than in omental fat, whereas PPARgamma mRNA expression is not significantly different between these fat depots. Skeletal muscle and SC fat PPARgamma and PGC-1alpha mRNA expression increased significantly in response to physical training.


CONCLUSIONS
Gene expression of PPARgamma and PGC-1alpha in human adipose tissue is related to markers of insulin resistance and cardiovascular risk. Increased muscle and adipose tissue PPARgamma and PGC-1alpha expression in response to physical training may mediate the beneficial effects of exercise on insulin sensitivity.
Ruschke
Karen
K
Department of Medicine, Endocrinology/Diabetes, University of Leipzig, Liebigstrasse 20, 04103 Leipzig, Germany.
Fishbein
Lauren
L
Dietrich
Arne
A
Klöting
Nora
N
Tönjes
Anke
A
Oberbach
Andreas
A
Fasshauer
Mathias
M
Jenkner
Jost
J
Schön
Michael R
MR
Stumvoll
Michael
M
Blüher
Matthias
M
Mantzoros
Christos S
CS
D000273:Adipose Tissue / Q000378:metabolism*; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001786:Blood Glucose / Q000378:metabolism; D003430:Cross-Sectional Studies; D015444:Exercise / Q000502:physiology*; D005260:Female; D015870:Gene Expression; D005786:Gene Expression Regulation / Q000502:physiology; D005951:Glucose Tolerance Test; D006360:Heat-Shock Proteins / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology*; D050356:Lipid Metabolism / Q000235:genetics; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000378:metabolism; D009765:Obesity / Q000235:genetics / Q000378:metabolism; D047495:PPAR gamma / Q000235:genetics* / Q000378:metabolism; D018579:Patient Selection; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012044:Regression Analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012307:Risk Factors; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
D001786:Blood Glucose; D006360:Heat-Shock Proteins; D008055:Lipids; D047495:PPAR gamma; C486497:PPARGC1A protein, human; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D012333:RNA, Messenger; D014157:Transcription Factors