Activation of CYP1A1 gene expression during primary culture of mouse hepatocytes

• Published in: Toxicology (Amsterdam) Vol. 216; no. 2; pp. 224 - 231
• Main Authors: Tamaki, Hisako, Sakuma, Tsutomu, Uchida, Yo-ichi, Jaruchotikamol, Atika, Nemoto, Nobuo
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 15.12.2005; Amsterdam Elsevier Science
• Subjects: Animals; Anti-oxidant; Biological and medical sciences; Cells, Cultured; CYP1A1; CYP1A2; Cytochrome P-450 CYP1A1 - drug effects; Cytochrome P-450 CYP1A1 - genetics; Cytochrome P-450 CYP1A1 - metabolism; Cytochrome P-450 CYP1A2 - genetics; Electrophoretic Mobility Shift Assay - methods; Enzyme Inhibitors - pharmacology; Gene Expression Regulation, Enzymologic - drug effects; Genistein - pharmacology; Hepatocytes - enzymology; Hydrogen Peroxide - pharmacology; Hydroquinones - pharmacology; Insulin - pharmacology; Isoflavones - pharmacology; Kinetin - pharmacology; Medical sciences; Mice; Mice, Inbred C57BL; Mouse primary culture; Okadaic acid; Okadaic Acid - pharmacology; Oxidative stress; Phosphorylation - drug effects; Protein kinase inhibitor; Purines - pharmacology; RNA, Messenger - drug effects; Time Factors; Toxicology; Transcriptional Activation; Oxidative stress; SSC; Hsp; Anti-oxidant; Arnt; TCDD; AhR; XRE; Protein kinase inhibitor; DCFH-DA; SDS-PAGE; CYP1A2; NF-1; CYP1A1; Okadaic acid; cDNA; CYP; GAPDH; Mouse primary culture; Protein inhibitor; Digestive system; Enzyme; Liver; Transferases; Cytochrome P450; Rodentia; Antioxidant; Gene expression; In vitro; Vertebrata; Mammalia; Hepatocyte; Mouse; Protein kinase; Animal; Primary culture
• ISSN: 0300-483X; 1879-3185
• DOI: 10.1016/j.tox.2005.08.007

Expression of CYP1A1 mRNA in mouse hepatocytes in primary culture was investigated. The expression was obvious on day 3 of culture without addition of any known ligands of the aryl hydrocarbon receptor and increased with culture period. Removal of insulin from and addition of hydrogen peroxide to the medium enhanced and suppressed the expression, respectively. The CYP1A1 mRNA expression was also enhanced in the presence of anti-oxidant, t-butylhydroquinone, in the medium. Several kinds of kinase inhibitors markedly increased the CYP1A1 mRNA expression. In contrast, the inhibitory expression was prolonged in the presence of okadaic acid, a potent inhibitor of serine/threonine phosphatase PP1 and PP2. These observations suggest that there might be a repressive pathway in the regulation of CYP1A1 mRNA expression and that the presently observed expression pathway differs at several points from those previously reported, such as ligand-activated aryl hydrocarbon receptor- or omeprazole-mediated expression. Modulation of CYP1A2 mRNA expression after exposing hepatocytes to agents affecting phosphorylation pathways differed from that of CYP1A1 mRNA. This implies that regulatory pathways for CYP1A1 and CYP1A2 expression may differ.