![]() |
|
|
IJ Lee, KS Jeong, BJ Roberts, AT Kallarakal, P Fernandez-Salguero, FJ Gonzalez and BJ Song
Laboratory of Neurogenetics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, Maryland 20852, USA. ijlee@dicbr.niaaa.nih.gov
The molecular mechanism of induction of cytochromes P4501A1/2 (CYP1A1/2) by a synthetic compound YH439 was studied in rodents as well as in cultured hepatoma cells. CYP1A1-mediated ethoxyresorufin-O- deethylase activity and amounts of its immunoreactive protein were increased in a time- and concentration-dependent manner after a single dose of YH439 (150 mg/kg). Northern blot analyses revealed that YH439 rapidly increased (< or = 2 hr) the levels of CYP1A1/2 mRNAs, resulting in an increase in CYP1A protein level by > 6-fold at 8 hr after injection. After YH439 administration, the levels of CYP1A1 and CYP1A2 mRNAs peaked at 8 hr and 16 hr, respectively, before returning to control levels at 16 and 24 hr. The CYP1A protein level, on the other hand, reached a maximum at 24 hr after YH439 treatment and returned to near-control levels at 72 hr. Nuclear run-on analyses revealed that YH439 induces CYP1A1/2 gene transcription as early as 2 hr after YH439 treatment. Cytosolic electrophoretic mobility shift assays suggested that YH439 activates the CYP1A1/2 genes through the aryl hydrocarbon (Ah) receptor and the xenobiotic response elements. The dependency on the Ah receptor for the induction of CYP1A1/2 by YH439 was confirmed by the lack of CYP1A1/2 induction in the Ah receptor knock-out mice (Ahr-1- ) as well as in murine hepatoma cells without a functional Ah receptor. Molecular structural analysis of YH439 and several other compounds indicated that the planarity and size of a molecule are important in its interaction with the Ah receptor and subsequent CYP1A1/2 induction. YH439 is a thiazolium compound with little aromaticity and with a two- dimensional structure different from that of the Ahs. Therefore, it represents a new class of Ah receptor ligand and CYP1A inducer.
This article has been cited by other articles:
![]() |
C. J. Gambone, J. M. Hutcheson, J. L. Gabriel, R. L. Beard, R. A.S. Chandraratna, K. J. Soprano, and D. R. Soprano Unique Property of Some Synthetic Retinoids: Activation of the Aryl Hydrocarbon Receptor Pathway Mol. Pharmacol., February 1, 2002; 61(2): 334 - 342. [Abstract] [Full Text] [PDF] |
||||
![]() |
M.-A. Bae, J.-E. Pie, and B. J. Song Acetaminophen Induces Apoptosis of C6 Glioma Cells by Activating the c-Jun NH2-Terminal Protein Kinase-Related Cell Death Pathway Mol. Pharmacol., October 1, 2001; 60(4): 847 - 856. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. Werlinder, M. Backlund, A. Zhukov, and M. Ingelman-Sundberg Transcriptional and Post-Translational Regulation of CYP1A1 by Primaquine J. Pharmacol. Exp. Ther., April 1, 2001; 297(1): 206 - 214. [Abstract] [Full Text] |
||||
![]() |
S. D. Seidel, V. Li, G. M. Winter, W. J. Rogers, E. I. Martinez, and M. S. Denison Ah Receptor-Based Chemical Screening Bioassays: Application and Limitations for the Detection of Ah Receptor Agonists Toxicol. Sci., May 1, 2000; 55(1): 107 - 115. [Abstract] [Full Text] [PDF] |
||||