Effects of cross-fostering and developmental exposure to mixtures of environmental contaminants on hepatic gene expression in prepubertal 21 days old and adult male Sprague-Dawley rats. Issue 1 (2nd January 2019)

• Record Type: Journal Article
• Authors: Desaulniers, D.; Khan, N.; Cummings-Lorbetskie, C.; Leingartner, K.; Xiao, G-H.; Williams, A.; Yauk, C.L.
• Is Part Of: Journal of toxicology and environmental health. Volume 82:Issue 1(2019)
• Page Start: 1
• Page End: 27
• Publication Date: 2019-01-02
• Subjects: Rat -- liver -- developmental exposure -- organochlorines -- persistent organic pollutants -- mixtures -- cross-fostering -- gene expression microarray; Toxicology -- Periodicals; Environmental health -- Periodicals; 615.90205
• DOI: 10.1080/15287394.2018.1542360
• Languages: English
• ISSNs: 1528-7394

Abstract

ABSTRACT: The notion that adverse health effects produced by exposure to environmental contaminants (EC) may be modulated by the presence of non-chemical stressors is gaining attention. Previously, our lab demonstrated that cross-fostering (adoption of a litter at birth) acted as a non-chemical stressor that amplified the influence of developmental exposure to EC on the glucocorticoid stress-response in adult rats. Using liver from the same rats, the aim of the current study was to investigate whether cross-fostering might also modulate EC-induced alterations in hepatic gene expression profiles. During pregnancy and nursing, Sprague-Dawley dams were fed cookies laced with corn oil (control, C) or a chemical mixture (M) composed of polychlorinated biphenyls (PCB), organochlorine pesticides (OCP), and methylmercury (MeHg), at 1 mg/kg/day. This mixture simulated the contaminant profile reported in maternal human blood. At birth, some control and M treated litters were cross-fostered to form two additional groups with different biological/nursing mothers (CC and MM). The hepatic transcriptome was analyzed by DNA microarray in male offspring at postnatal days 21 and 78–86. Mixture exposure altered the expression of detoxification and energy metabolism genes in both age groups, but with different sets of genes affected at day 21 and 78–86. Cross-fostering modulated the effects of M on gene expression pattern (MM vs M), as well as expression of energy metabolism genes between control groups (CC vs C). In conclusion, while describing short and long-term effects of developmental exposure to EC on hepatic transcriptomes, these cross-fostering results further support the consideration of non-chemical stressors in EC risk assessments.