Adipose tissue distribution and quantification of PPARβ/δ and PPARγ1-3 mRNAs:: Discordant gene expression in subcutaneous, retroperitoneal and visceral adipose tissue of morbidly obese patients

Background: Adipose tissue (AT) metabolism is altered in obese subjects, and the reestablishment of energy homeostasis requires the identification and regulation of genes with altered patterns. The aim of this study was to compare mRNA expression of PPAR beta/delta and PPAR gamma 1-3 in morbidly obese and non-obese patients. The expression pattern of these receptors in various abdominal adipose tissues, subcutaneous (SAT), retroperitoneal (RAT) and visceral (VAT), was also evaluated. Methods: The AT depots were obtained by surgery. Total RNAs were extracted using TRIzol. PPARs reverse transcripts were determined by quantitative polymerase chain reaction (qRT-PCR). Results: The amounts of PPAR beta/delta mRNA indifferent depots of morbidly obese AT showed a significant decrease in VAT (P < 0.05). In the non-obese group, the level of PPAR beta/delta was higher in SAT (P < 0.05), but PPAR gamma 1-3 was not differentially expressed in obese and non-obese depots. When comparing obese and non-obese, the results revealed a decrease in PPAR beta/delta expression in SAT (P=0.058) and VAT (P=0.094) of the morbidly obese. PPAR gamma 1-3 mRNA expression was increased significantly in SAT (P=0.022) and decreased in RAT (P=0.034) in morbidly obese subjects. PPAR beta/delta expression in SAT and VAT correlated negatively with hip size and insulin serum respectively. PPAR gamma 1-3 expression in RAT correlated negatively with waist and hip circumference and in VAT correlated positively with waist size. Conclusions: The present study demonstrates that PPAR beta/delta and PPAR gamma 1-3 mRNAs are quantitatively different in AT of morbidly obese individuals compared to non-obese, and that PPAR beta/delta mRNA levels are characteristic for each AT depot.