Effects of TCDD on the expression of nuclear encoded mitochondrial genes

Journal Article · Thu Jul 15 04:00:00 EDT 2010 · Toxicology and Applied Pharmacology

DOI:https://doi.org/10.1016/j.taap.2010.04.006· OSTI ID:21451173

Forgacs, Agnes L ^[1]; Burgoon, Lyle D ^[1]; Lynn, Scott G; LaPres, John J ^[1]; Zacharewski, Timothy ^[1]

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1. Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824 (United States)

Generation of mitochondrial reactive oxygen species (ROS) can be perturbed following exposure to environmental chemicals such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Reports indicate that the aryl hydrocarbon receptor (AhR) mediates TCDD-induced sustained hepatic oxidative stress by decreasing hepatic ATP levels and through hyperpolarization of the inner mitochondrial membrane. To further elucidate the effects of TCDD on the mitochondria, high-throughput quantitative real-time PCR (HTP-QRTPCR) was used to evaluate the expression of 90 nuclear genes encoding mitochondrial proteins involved in electron transport, oxidative phosphorylation, uncoupling, and associated chaperones. HTP-QRTPCR analysis of time course (30 {mu}g/kg TCDD at 2, 4, 8, 12, 18, 24, 72, and 168 h) liver samples obtained from orally gavaged immature, ovariectomized C57BL/6 mice identified 54 differentially expressed genes (|fold change| > 1.5 and P-value < 0.1). Of these, 8 exhibited a sigmoidal or exponential dose-response profile (0.03 to 300 {mu}g/kg TCDD) at 4, 24 or 72 h. Dose-responsive genes encoded proteins associated with electron transport chain (ETC) complexes I (NADH dehydrogenase), III (cytochrome c reductase), IV (cytochrome c oxidase), and V (ATP synthase) and could be generally categorized as having proton gradient, ATP synthesis, and chaperone activities. In contrast, transcript levels of ETC complex II, succinate dehydrogenase, remained unchanged. Putative dioxin response elements were computationally found in the promoter regions of all 8 dose-responsive genes. This high-throughput approach suggests that TCDD alters the expression of genes associated with mitochondrial function which may contribute to TCDD-elicited mitochondrial toxicity.

• OSTI ID: 21451173
• Journal Information: Toxicology and Applied Pharmacology, Journal Name: Toxicology and Applied Pharmacology Journal Issue: 1-2 Vol. 246; ISSN TXAPA9; ISSN 0041-008X
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
BODY
CELL CONSTITUENTS
DIGESTIVE SYSTEM
DIOXIN
GENES
GLANDS
HETEROCYCLIC COMPOUNDS
LIVER
MAMMALS
MEMBRANE PROTEINS
MICE
MITOCHONDRIA
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
ORGANS
PROTEINS
RECEPTORS
RODENTS
TOXICITY
VERTEBRATES