Differential tissue regulation of peroxisome proliferator-activated receptor α (PPARα) and cannabinoid receptor 1 (CB1) gene transcription pathways by diethylene glycol dibenzoate (DEGB): preliminary observations in a seabream (Sparus aurata) in vivo model

Today a variety of endocrine disrupting chemicals (EDCs) are recognized in the group of metabolic disruptors, a wide range of environmental contaminants that alter energy balance regulation by affecting the peroxisome proliferator-activated receptor (PPAR)/retinoid X receptor (RXR) pathway. Herein, we investigated the effect of diethylene glycol dibenzoate (DEGB), a dibenzoate-based plasticizer used as alternative to phthalates, on the expression of key genes involved in lipid metabolism and energy balance by using Sparta aurata juveniles as models. We also evaluated the correlation between cannabinoid receptor 1 (C81) and PPAR alpha transcriptional patterns in both liver and brain tissues. Exposure to the highest DEGB concentration differentially modulated PPAR alpha/CB1 transcriptional pathways in liver/brain tissues of seabream. We hypothesize that, at peripheral level (i.e. liver), DEGB acts as PPAR alpha agonist resulting in a potential stimulation of key lipolytic genes and a concomitant down-regulation of endocannabinoid metabolic enzyme genes.