Gene expression profiling in subcutaneous, visceral and epigastric adipose tissues of patients with extreme obesity.
OBJECTIVE
The goal of the present study was to identify differences in gene expression between SAT, VAT and EAT depots in Class III severely obese individuals.


METHODS
Human subcutaneous (SAT) and visceral (VAT) adipose tissues exhibit differential gene expression profiles. There is little information, however, about the other proximal white adipose tissue, epigastric (EAT), in terms of its function and contribution to metabolism.


METHODS
Using RNA from adipose biospecimens obtained from Class III severely obese patients undergoing open Roux-en-Y gastric bypass surgery, we compared gene expression profiles between SAT, VAT and EAT, using microarrays validated by real-time quantitative PCR.


RESULTS
The three depots were found to share 1907 genes. VAT had the greatest number of genes (66) expressed exclusively in this depot, followed by SAT (23), and then EAT (14). Moreover, VAT shared more genes with EAT (65) than with SAT (38). Further analyses using ratios of SAT/EAT, VAT/EAT and SAT/VAT identified specific as well as overlapping networks and pathways of genes representing dermatological diseases, inflammation, cell cycle and growth, cancer and development. Targeted analysis of genes, having a role in adipose tissue development and function, revealed that Peroxisome proliferator-activated receptor Gamma Coactivator 1-alpha (PGC1-α) that regulates the precursor of the hormone Irisin (FNCD5) were abundantly expressed in all three fat depots, along with fibroblast growth factors (FGF) FGF1, FGF7 and FGF10, whereas, FGF19 and FGF21 were undetectable.


CONCLUSIONS
These data indicate that EAT has more in common with VAT, suggesting similar metabolic potential. The human epigastric adipose depot could have a significant functional role in metabolic diseases and should be further investigated.
1] Weis Center for Research, Danville, PA, USA [2] Department of Biochemistry and Molecular Biology and Department of Pathology and Laboratory Medicine, Pennsylvania State University, Hershey, PA, USA.
G S
GS
Gerhard
Weis Center for Research, Danville, PA, USA.
A M
AM
Styer
Department of Surgery, Geisinger Medical Center, Danville, PA, USA.
W E
WE
Strodel
Weis Center for Research, Danville, PA, USA.
S L
SL
Roesch
Weis Center for Research, Danville, PA, USA.
A
A
Yavorek
Weis Center for Research, Danville, PA, USA.
D J
DJ
Carey
Institute of Obesity, Geisinger Medical Center, Danville, PA, USA.
G C
GC
Wood
Department of Surgery, Geisinger Medical Center, Danville, PA, USA.
A T
AT
Petrick
Department of Surgery, Geisinger Medical Center, Danville, PA, USA.
J
J
Gabrielsen
Department of Surgery, Geisinger Medical Center, Danville, PA, USA.
A
A
Ibele
Institute of Obesity, Geisinger Medical Center, Danville, PA, USA.
P
P
Benotti
Department of General and Internal Medicine, Geisinger Medical Center, Danville, PA, USA.
D D
DD
Rolston
1] Institute of Obesity, Geisinger Medical Center, Danville, PA, USA [2] Department of Gastroenterology, Geisinger Medical Center, Danville, PA, USA.
C D
CD
Still
1] Weis Center for Research, Danville, PA, USA [2] Institute of Obesity, Geisinger Medical Center, Danville, PA, USA.
G
G
Argyropoulos
D005260:Female; D016220:Fibroblast Growth Factor 1 / Q000378:metabolism*; D051526:Fibroblast Growth Factor 10 / Q000378:metabolism*; D051523:Fibroblast Growth Factor 7 / Q000378:metabolism*; D015390:Gastric Bypass; D020869:Gene Expression Profiling; D006801:Humans; D007249:Inflammation / Q000235:genetics / Q000473:pathology*; D050152:Intra-Abdominal Fat / Q000473:pathology*; D008297:Male; D046228:Microarray Analysis; D008875:Middle Aged; D009767:Obesity, Morbid / Q000235:genetics / Q000473:pathology*; D047495:PPAR gamma / Q000378:metabolism; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D060888:Real-Time Polymerase Chain Reaction; D012720:Severity of Illness Index; D050151:Subcutaneous Fat / Q000473:pathology*; D014157:Transcription Factors / Q000378:metabolism*
C496463:FGF10 protein, human; D051526:Fibroblast Growth Factor 10; D047495:PPAR gamma; C486497:PPARGC1A protein, human; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D014157:Transcription Factors; D016220:Fibroblast Growth Factor 1; D051523:Fibroblast Growth Factor 7