Ontology highlight
ABSTRACT: Background
Coplanar polychlorinated biphenyls (PCBs) promote adipocyte inflammation and impair glucose homeostasis in lean mice. The diabetes-promoting effects of lipophilic PCBs have been observed only during weight loss in obese mice. The molecular mechanisms linking PCB exposures to impaired glucose metabolism are unclear.Objectives
In this study we tested the hypothesis that coplanar PCBs act at adipocyte aryl hydrocarbon receptors (AhRs) to promote adipose inflammation and impair glucose homeostasis in lean mice and in obese mice during weight loss.Methods and results
PCB-77 administration impaired glucose and insulin tolerance in LF (low fat diet)-fed control (AhR(fl/fl)) mice but not in adipocyte AhR-deficient mice (AhR(AdQ)). Unexpectedly, AhR(AdQ) mice exhibited increased fat mass when fed a standard LF or high fat (HF) diet. In mice fed a HF diet, both genotypes became obese, but AhR(AdQ) mice administered vehicle (VEH) exhibited increased body weight, adipose mass, adipose inflammation, and impaired glucose tolerance compared with AhR(fl/fl) controls. Impairment of glucose homeostasis in response to PCB-77 was not observed in obese mice of either genotype. However, upon weight loss, AhR(fl/fl) mice administered PCB-77 exhibited increased abundance of adipose tumor necrosis factor-? (TNF-?) mRNA and impaired glucose homeostasis compared with those administered VEH. In contrast, PCB-77 had no effect on TNF-? or glucose homeostasis in AhR(AdQ) mice exhibiting weight loss.Conclusions
Our results demonstrate that adipocyte AhR mediates PCB-induced adipose inflammation and impairment of glucose homeostasis in mice. Moreover, deficiency of AhR in adipocytes augmented the development of obesity, indicating that endogenous ligand(s) for AhR regulate adipose homeostasis.
SUBMITTER: Baker NA
PROVIDER: S-EPMC4590748 | biostudies-literature | 2015 Oct
REPOSITORIES: biostudies-literature
Baker Nicki A NA Shoemaker Robin R English Victoria V Larian Nika N Sunkara Manjula M Morris Andrew J AJ Walker Mary M Yiannikouris Frederique F Cassis Lisa A LA
Environmental health perspectives 20150303 10
<h4>Background</h4>Coplanar polychlorinated biphenyls (PCBs) promote adipocyte inflammation and impair glucose homeostasis in lean mice. The diabetes-promoting effects of lipophilic PCBs have been observed only during weight loss in obese mice. The molecular mechanisms linking PCB exposures to impaired glucose metabolism are unclear.<h4>Objectives</h4>In this study we tested the hypothesis that coplanar PCBs act at adipocyte aryl hydrocarbon receptors (AhRs) to promote adipose inflammation and i ...[more]