Effect of beta-naphthoflavone on AhR-regulated genes (CYP1A1, 1A2, 1B1, 2S1, Nrf2, and GST) and antioxidant enzymes in various brain regions of pig
| Autor: | P. Giovanni Gervasi, Roberto Tolando, Francesco Rossignolo, Vincenzo Longo, Annalisa Nannelli, Paolo Rossato |
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| Rok vydání: | 2009 |
| Předmět: |
Male
medicine.medical_specialty Aryl hydrocarbon receptor nuclear translocator DNA Complementary NF-E2-Related Factor 2 Swine Central nervous system Sus scrofa Toxicology Isozyme Polymerase Chain Reaction Gene Expression Regulation Enzymologic Superoxide dismutase Cytochrome P-450 Enzyme System beta-Naphthoflavone Internal medicine medicine Animals RNA Messenger Enzyme Inhibitors Receptor Crosses Genetic Glutathione Transferase Glutathione Peroxidase biology Superoxide Dismutase Cytochrome P450 Brain respiratory system Aryl hydrocarbon receptor Catalase Molecular biology Isoenzymes Endocrinology medicine.anatomical_structure Glutathione Reductase Liver Receptors Aryl Hydrocarbon CYP2S1 Enzyme Induction biology.protein Microsomes Liver RNA Orchiectomy |
| Zdroj: | Toxicology. 265(3) |
| ISSN: | 1879-3185 |
| Popis: | The constitutive and inducible expression of aryl hydrocarbon receptor (AhR) and of the AhR-regulated genes coding for CYP1A1, CYP1A2, CYP1B1, CYP2S1, and Nrf2 was investigated by real-time or traditional PCR in cerebral areas (cortex, cerebellum, midbrain, and hippocampus), blood-brain interfaces (meninges and brain microvessels) and liver obtained from control pigs and from pigs treated with beta-naphthoflavone (betaNF), a potent AhR agonist. The enzymatic activities of ethoxyresorufin-O-deethylase (EROD), and methoxyresorufin-O-deethylase (MEROD), marker for CYP1A1 and CYP1A2, the GST and various antioxidant enzymes (catalase, superoxide dismutase, GSSG-reductase, and GSH-peroxidase) were also determined in the same CNS regions. The AhR, CYP1A1, CYP1A2, CYP1B1, Nrf2 mRNAs were detected, although at different extent, in all the CNS regions, while CYP2S1 mRNA was detected only in midbrain. In the blood-brain interfaces, the constitutive basal expression of AhR and CYP1A1 was comparable to the hepatic one and even higher for CYP1B1 and Nrf2. The treatment with betaNF determined the induction of CYP1A1 and 1B1 (but not of AhR, CYP1A2, and Nrf2) mRNA levels in various CNS areas; notably, CYP1A1 mRNA was increased to about 300-fold in the microvessels. The analysis of enzymatic activities revealed that EROD, but not MEROD, was induced in microsomes but not in mitochondria of all the CNS areas. However, the mitochondrial EROD activities were comparable (in midbrain, meninges) or higher (in cortex, cerebellum, hippocampus) than the microsomal ones, suggesting an important metabolic function of CYP1A1 in this subcellular localization. The activities of GST and antioxidant enzymes were detected in all CNS tissues, with levels lower than the hepatic ones, but found quite evenly distributed and marginally affected by betaNF treatment. The high expression of metabolic enzymes found in blood-brain interfaces could represent a very important defence toward toxins of CNS. |
| Databáze: | OpenAIRE |
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