Expression of Obesity Markers and Persistent Organic Pollutants Levels in Adipose Tissue of Obese Patients: Reinforcing the Obesogen Hypothesis?

PLoS One. 2014 Jan 10;9(1):e84816. doi: 10.1371/journal.pone.0084816. eCollection 2014.

Abstract

Introduction: Persistent Organic Pollutants (POPs) accumulate in adipose tissue and some are described to possess endocrine disrupting capacities. Therefore, it is important to evaluate their effects on key endocrine pathways in adipose tissue (AT), to further evaluate their potential role in metabolic pathologies such as obesity.

Objectives: THE AIM IS TWOFOLD: (i) evaluate gene expression levels of obesity marker genes, i.e. the adipokines leptin (LEP), adiponectin (ADIPOQ) and Tumor Necrosis Factor α (TNFα) and the nuclear receptor, Peroxisome Proliferator Activated Receptor γ (PPARγ) in paired subcutaneous (SAT) and visceral (VAT) AT of obese subjects (n = 50) and to relate these values to serum concentrations of LEP and ADIPOQ (ii) evaluate the association of expression levels of marker genes in AT and serum with POP concentrations in AT.

Results and conclusions: Leptin and adiponectin levels in serum were positively correlated to respectively expression levels of leptin in SAT and adiponectin in VAT. Our study shows more significant correlations between gene expression of obesity marker genes and POP concentrations in VAT compared to SAT. Since VAT is more important than SAT in pathologies associated with obesity, this suggests that POPs are able to influence the association between obesity and the development of associated pathologies. Moreover, this finding reveals the importance of VAT when investigating the obesogen hypothesis. Concerning PPARγ expression in VAT, negative correlations with polychlorinated biphenyls (PCBs) concentrations were found in non T2D patients. LEP serum concentrations correlated with several PCBs in women whereas in men no correlations were found. This strengthens the potential importance of gender differences in obesity and within the obesogen hypothesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipose Tissue / metabolism*
  • Adolescent
  • Adult
  • Biomarkers / blood
  • Biomarkers / metabolism
  • Female
  • Gene Expression*
  • Humans
  • Intra-Abdominal Fat / metabolism
  • Male
  • Middle Aged
  • Obesity / genetics*
  • Obesity / metabolism*
  • Subcutaneous Fat / metabolism
  • Young Adult

Substances

  • Biomarkers

Grant support

This study was funded by the University of Antwerp (UA) through a GOA project (Endocrine disrupting environmental chemicals: from accumulation to their role in the global ‘neuro-endocrine’ epidemic of obesity and its metabolic consequences; FA020000/2/3565). APF thanks the Institute for the Promotion of Innovation by Science and Technology in Flanders (IWT) for her doctoral scholarship. GM and ACD acknowledge respectively the UA and the Research Scientific Foundation-Flanders (FWO) for their postdoctoral fellowship. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.