Parallel down-regulation of FOXO1, PPARγ and adiponectin mRNA expression in visceral adipose tissue of class III obese individuals

Abstract

Objective: Adipose tissue is responsible for secretion of several cytokines that mediate systemic effects on obesity and insulin resistance. Subcutaneous abdominal adipose tissue (SAT) and visceral adipose tissue (VAT) are metabolically different and have differences in their gene expression profile. Our study evaluated the expression of adiponectin, FOXO1, PPARγ, and SIRT1 in VAT and SAT of non-obese and class III obese subjects.

Methods: The adipose tissue samples were obtained by surgery. Reverse transcripts of studied genes were determined by quantitative real-time polymerase chain reaction (qRT-PCR).

Results: Comparing the different lipid depots, adiponectin expression was lower only in VAT of obese individuals (p = 0.043); FOXO1 and PPARγ levels were decreased in VAT of both groups. When non-obese and obese were compared, only adiponectin expression was lower in SAT and in VAT of obese subjects (p = 0.004 and p = 0.002, respectively). No difference was found with regard to SIRT1 levels in VAT or SAT in both groups. FOXO1 expression in SAT of obese subjects had a negative correlation with age (r = -0.683; p = 0.029) and triglyceride serum levels (r = -0.794; p = 0.006).

Conclusion: The decrease mRNA expression of this genes in VAT, responsible for central adiposity, may be associated with an increased risk of obesity and co-morbidities.