Subcutaneous abdominal adipose tissue subcompartments: potential role in rosiglitazone effects.
Abdominal visceral tissue (VAT) and subcutaneous adipose tissue (SAT), comprised of superficial-SAT (sSAT) and deep-SAT (dSAT), are metabolically distinct. The antidiabetic agents thiazolidinediones (TZDs), in addition to their insulin-sensitizing effects, redistribute SAT suggesting that TZD action involves adipose tissue depot-specific regulation. We investigated the expression of proteins key to adipocyte metabolism on differentiated first passage (P1) preadipocytes treated with rosiglitazone, to establish a role for the diverse depots of abdominal adipose tissue in the insulin-sensitizing effects of TZDs. Adipocytes and preadipocytes were isolated from sSAT, dSAT, and VAT samples obtained from eight normal subjects. Preadipocytes (P1) left untreated (U) or treated with a classic differentiation cocktail (DI) including rosiglitazone (DIR) for 9 days were evaluated for strata-specific differences in differentiation including peroxisome proliferator-activated receptor-gamma (PPAR-gamma) and lipoprotein lipase (LPL) expression, insulin sensitivity via adiponectin and glucose transport-4 (GLUT4), glucocorticoid metabolism with 11 beta-hydroxysteroid dehydrogenase type-1 (11 beta HSD1), and alterations in the adipokine leptin. While depot-specific differences were absent with the classic differentiation cocktail, with rosiglitazone sSAT had the most potent response followed by dSAT, whereas VAT was resistant to differentiation. With rosiglitazone, universal strata effects were observed for PPAR-gamma, LPL, and leptin, with VAT in all cases expressing significantly lower basal expression levels. Clear dSAT-specific changes were observed with decreased intracellular GLUT4. Specific sSAT alterations included decreased 11 beta HSD1 whereas secreted adiponectin was potently upregulated in sSAT with respect to dSAT and VAT. Overall, the subcompartments of SAT, sSAT, and dSAT, appear to participate in the metabolic changes that arise with rosiglitazone administration.
Walker
Gillian E
GE
Laboratory of Molecular Biology, I.R.C.C.S. Istituto Auxologico Italiano, Piancavallo (VB), Italy. walkergi68@yahoo.com
Marzullo
Paolo
P
Verti
Barbara
B
Guzzaloni
Gabriele
G
Maestrini
Sabrina
S
Zurleni
Francesco
F
Liuzzi
Antonio
A
Di Blasio
Anna Maria
AM
D043205:11-beta-Hydroxysteroid Dehydrogenase Type 1 / Q000235:genetics / Q000378:metabolism; D017667:Adipocytes / Q000187:drug effects / Q000378:metabolism; D052242:Adiponectin / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects; D015536:Down-Regulation; D005260:Female; D005947:Glucose / Q000378:metabolism; D051275:Glucose Transporter Type 4 / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D050152:Intra-Abdominal Fat / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D020738:Leptin / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D008071:Lipoprotein Lipase / Q000235:genetics / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D047495:PPAR gamma / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000077154:Rosiglitazone; D050151:Subcutaneous Fat / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D045162:Thiazolidinediones / Q000494:pharmacology*
D052242:Adiponectin; D051275:Glucose Transporter Type 4; D007004:Hypoglycemic Agents; D020738:Leptin; D047495:PPAR gamma; D012333:RNA, Messenger; C495692:SLC2A4 protein, human; D045162:Thiazolidinediones; D000077154:Rosiglitazone; D043205:11-beta-Hydroxysteroid Dehydrogenase Type 1; D008071:Lipoprotein Lipase; D005947:Glucose