Tissue specific changes in the expression of glutamate–cysteine ligase mRNAs in mice exposed to methylmercury

• Published in: Toxicology letters Vol. 122; no. 2; pp. 119 - 129
• Main Authors: Dı́az, Dolores, Krejsa, Cecile M., White, Collin C., Keener, Cassie L., Farin, Federico M., Kavanagh, Terrance J.
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 20.06.2001; Amsterdam Elsevier Science
• Subjects: Animals; Biological and medical sciences; Chemical and industrial products toxicology. Toxic occupational diseases; Female; Gene Expression Regulation, Enzymologic - drug effects; Glutamate-Cysteine Ligase - genetics; Glutamate-Cysteine Ligase - metabolism; Glutamate–cysteine ligase; Glutathione; Glutathione - analysis; Glutathione - metabolism; Medical sciences; Metals and various inorganic compounds; Methylmercury; Methylmercury Compounds - toxicity; Mice; Mice, Inbred C57BL; Organ Specificity; RNA, Messenger - analysis; Toxicology; Glutamate–cysteine ligase; Methylmercury; Glutathione; Catalytic subunit; Toxicity; Liver; Small intestine; Kidney; Messenger RNA; Ligases; Female; Mercury Organic compounds; Mechanism of action; Glutamate-cysteine ligase; Carbon-nitrogen ligases; Enzyme; Rodentia; Tissue specificity; Regulatory subunit; Gene expression; Heavy metal; Pollutant; Vertebrata; Mammalia; Mouse; Sulfur peptide; Animal
• ISSN: 0378-4274; 1879-3169
• DOI: 10.1016/S0378-4274(01)00341-1

Glutamate–cysteine ligase (GLCL), the rate-limiting enzyme in glutathione (GSH) synthesis is composed of two subunits, a catalytic (GLCLc) and a regulatory subunit (GLCLr). These two subunits are known to be differentially regulated in vitro, in different cell types and in response to various xenobiotic exposures. In this study, we examined whether these two subunits can also be differentially regulated in vivo. We found that GLCLc and GLCLr are differentially regulated at the transcriptional level in a tissue-dependent manner in female mice treated with methylmercury (MeHg). MeHg caused a downregulation of both subunit mRNAs in the liver, upregulation of both subunit mRNAs in the kidney and upregulation of only the catalytic subunit mRNA in the small intestine of female mice treated with a single dose of MeHg (6 mg/kg) by intraperitoneal injection. These results suggest that GLCLc and GLCLr can be differentially regulated in vivo, and that this regulation is tissue dependent in the mouse.