title: Identification of potential mechanisms of toxicity after di-(2-ethylhexyl)-phthalate (DEHP) adult exposure in the liver using a systems biology approach.
abstract: Phthalates are industrial additives widely used as plasticizers. In addition to deleterious effects on male genital development, population studies have documented correlations between phthalates exposure and impacts on reproductive tract development and on the metabolic syndrome in male adults. In this work we investigated potential mechanisms underlying the impact of DEHP on adult mouse liver in vivo. A parallel analysis of hepatic transcript and metabolic profiles from adult mice exposed to varying DEHP doses was performed. Hepatic genes modulated by DEHP are predominantly PPARalpha targets. However, the induction of prototypic cytochrome P450 genes strongly supports the activation of additional NR pathways, including Constitutive Androstane Receptor (CAR). Integration of transcriptomic and metabonomic profiles revealed a correlation between the impacts of DEHP on genes and metabolites related to heme synthesis and to the Rev-erbalpha pathway that senses endogenous heme level. We further confirmed the combined impact of DEHP on the hepatic expression of Alas1, a critical enzyme in heme synthesis and on the expression of Rev-erbalpha target genes involved in the cellular clock and in energy metabolism. This work shows that DEHP interferes with hepatic CAR and Rev-erbalpha pathways which are both involved in the control of metabolism. The identification of these new hepatic pathways targeted by DEHP could contribute to metabolic and endocrine disruption associated with phthalate exposure. Gene expression profiles performed on microdissected testis territories displayed a differential responsiveness to DEHP. Altogether, this suggests that impacts of DEHP on adult organs, including testis, could be documented and deserve further investigations.
authors.affiliation: Pôle de Toxicologie Alimentaire, Laboratoire de Pharmacologie et Toxicologie, Institut National de la Recherche Agronomique INRA UR66, Toulouse Cedex 3, France.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Eveillard
authors.forename: Frédéric
authors.initials: F
authors.lastname: Lasserre
authors.forename: Marie
authors.initials: M
authors.lastname: de Tayrac
authors.forename: Arnaud
authors.initials: A
authors.lastname: Polizzi
authors.forename: Sandrine
authors.initials: S
authors.lastname: Claus
authors.forename: Cécile
authors.initials: C
authors.lastname: Canlet
authors.forename: Laïla
authors.initials: L
authors.lastname: Mselli-Lakhal
authors.forename: Gaëlle
authors.initials: G
authors.lastname: Gotardi
authors.forename: Alain
authors.initials: A
authors.lastname: Paris
authors.forename: Hervé
authors.initials: H
authors.lastname: Guillou
authors.forename: Pascal G P
authors.initials: PG
authors.lastname: Martin
authors.forename: Thierry
authors.initials: T
authors.lastname: Pineau
mesh_terms: D000818:Animals; D004051:Diethylhexyl Phthalate / Q000633:toxicity*; D020869:Gene Expression Profiling; D006418:Heme / Q000096:biosynthesis; D008099:Liver / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D051379:Mice; D049490:Systems Biology; D014158:Transcription, Genetic
chemical_list: D006418:Heme; D004051:Diethylhexyl Phthalate