Induction of cytochromes P450, caspase-3 and DNA damage by PCB3 and its hydroxylated metabolites in porcine ovary.
Polychlorinated biphenyl (PCBs) levels of tens and hundreds of pg/ml for individual congeners are measured in human follicular fluid. PCB3 (4-chlorobiphenyl), caused a significant increase in estradiol secretion in porcine granulose-theca cell co-cultures and its two metabolites, 4-OH-PCB3 and 3,4-diOH-PCB3, were even more potent than PCB3 itself [Ptak, A., Ludewig, G., Lehmler, H.J., Wojtowicz, A.K., Robertson, L.W., Gregoraszczuk, E.L. 2005. Comparison of the actions of 4-chlorobiphenyl and its hydroxylated metabolites on estradiol secretion by ovarian follicles in primary cells in culture. Reprod. Toxicol. 20, 57-64]. The question is whether these follicle cells are potentially able to metabolize PCB3 to hydroxylated and genotoxic or cytotoxic intermediates. We report here that granulose-theca co-cultures express xenobiotic-metabolizing cytochrome P450 activities, with CYP1A1>CYP2B>>CYP1A2. A significant increase in CYP1A1 and 2B, but not CYP1A2, activity was seen in cells that were exposed to 6 ng/ml PCB3 or 20 nM 17-beta-estradiol. An increase in caspase-3 activity, indicative for apoptosis, was only observed in PCB3-exposed cells after 24 h exposure. Genotoxicity, determined with the Comet assay, was initially reduced after 24 h exposure to PCB3 and both metabolites compared to untreated controls, followed by a significant transient increase in Comets at the 4 and 24 h time point with PCB3 and 4-OH-PCB3. 3,4-diOH-PCB3 induced a significant increase only after 72 h of recovery. We hypothesize that these biphasic damage kinetics may be due to cross-links caused by adduct formation. These results show for the first time that granulose-theca cells in co-culture express CYP1A1, 2B and 1A2 activities and that PCBs at concentrations that are reached in the environment induce genotoxicity in granulosa cells.
Ptak
Anna
A
Laboratory of Physiology and Toxicology of Reproduction, Department of Animal Physiology, Institute of Zoology, Jagiellonian University, Ingardena 6, Krakow, Poland.
Ludewig
Gabriele
G
Kapiszewska
Maria
M
Magnowska
Zofia
Z
Lehmler
Hans-Joachim
HJ
Robertson
Larry W
LW
Gregoraszczuk
Ewa L
EL
D000818:Animals; D001141:Aromatase / Q000378:metabolism; D001713:Biphenyl Compounds / Q000633:toxicity*; D053148:Caspase 3; D020169:Caspases / Q000096:biosynthesis*; D018920:Coculture Techniques; D020552:Comet Assay; D019363:Cytochrome P-450 CYP1A1 / Q000378:metabolism; D019362:Cytochrome P-450 CYP2B1 / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis* / Q000378:metabolism; D004249:DNA Damage / Q000187:drug effects*; D004785:Environmental Pollutants / Q000633:toxicity*; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D006107:Granulosa Cells / Q000187:drug effects / Q000201:enzymology; D006900:Hydroxylation; D007527:Isoenzymes / Q000378:metabolism; D010053:Ovary / Q000187:drug effects / Q000201:enzymology*; D010088:Oxidoreductases / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D013552:Swine; D013799:Theca Cells / Q000187:drug effects / Q000201:enzymology
D001713:Biphenyl Compounds; D004785:Environmental Pollutants; D007527:Isoenzymes; D017382:Reactive Oxygen Species; D004958:Estradiol; D003577:Cytochrome P-450 Enzyme System; D010088:Oxidoreductases; C076307:methoxyresorufin-O-demethylase; D001141:Aromatase; D019363:Cytochrome P-450 CYP1A1; D019362:Cytochrome P-450 CYP2B1; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases; C006983:4-chlorobiphenyl