Congener-specific action of PBDEs on steroid secretion, CYP17, 17β-HSD and CYP19 activity and protein expression in porcine ovarian follicles

Karpeta, Anna; Rak, Agnieszka; Jerzak, J.; Gregoraszczuk, Ewa Ł.

doi:10.1016/j.toxlet.2011.08.005

Cited by 30 publications

(19 citation statements)

References 25 publications

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“…Difference in the changes of NaR and GST responding to different PBDEs may be as the result of congener-specific action of PBDEs on NaR and GST activities. Similar phenomena were observed in the effects of PBDEs on GST, deiodinase, and CYP17 activities in porcine ovarian follicles (Karpeta et al, 2011) and fishes (Roberts et al, 2011). The degradation reaction of PBDEs stopped gradually with the NaR and GST became inactive.…”

Section: Responses Of Root Enzymes To the Exposure Of Pbdessupporting

confidence: 74%

In vitro biotransformation of PBDEs by root crude enzyme extracts: Potential role of nitrate reductase (NaR) and glutathione S-transferase (GST) in their debromination

et al. 2013

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h i g h l i g h t s" PBDEs could be debrominated and hydroxylated by the root crude enzyme extracts. " Debromination was the main degradation pathway. " In vitro and in vivo exposure to PBDEs produced the similar enzyme responses. " NaR and GST were the key enzymes in the plant degradation of PBDEs. a r t i c l e i n f o t r a c tIn order to investigate the enzyme transformation of PBDEs and to track the key enzymes involved in PBDE degradation in plants, in vivo exposure of plants of ryegrass, pumpkin and maize and in vitro exposure of their root crude enzyme extracts to PBDEs were conducted. Degradation of PBDEs in the root crude enzyme solutions fit well with the first order kinetics (R 2 = 0.52-0.97, P < 0.05), and higher PBDEs degraded faster than the lower ones. PBDEs could be transformed to lower brominated PBDEs and hydroxylated-PBDEs by the root crude enzyme extracts with debromination as the main pathway which contributed over 90% of PBDE depletion. In vitro and in vivo exposure to PBDEs produced similar responses in root enzyme activities of which the nitroreductase (NaR) and glutathione-transferase (GST) activities decreased significantly, while the peroxidase, catalase and cytochrome P-450 activities had no significant changes. Furthermore, higher enzyme concentrations of NaR and GST led to higher PBDE debromination rates, and the time-dependent activities of NaR and GST in the root crude enzyme extracts were similar to the trends of PBDE depletion. All these results suggest that NaR and GST were the key enzymes responsible for PBDE degradation. This conclusion was further confirmed by the in vitro debromination of PBDEs with the commercial pure NaR and GST.

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Section: Responses Of Root Enzymes To the Exposure Of Pbdessupporting

confidence: 74%

In vitro biotransformation of PBDEs by root crude enzyme extracts: Potential role of nitrate reductase (NaR) and glutathione S-transferase (GST) in their debromination

et al. 2013

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“…Certain PBDEs have been shown to decrease P 4 synthesis in mouse Leydig tumor cells (Han et al 2012) while other PBDEs have been shown to increase P 4 synthesis in the ovarian follicles of pigs (Karpeta & Gregoraszczuk 2010). Proposed mechanisms of action in the latter study include modulation of key steroidogenic genes, many of which are highly conserved among vertebrates (Karpeta et al 2011).…”

Section: Discussionmentioning

confidence: 84%

The reproductive hormone cycle of adult female American alligators from a barrier island population

Hamlin

Lowers²,

Kohno

et al. 2014

Reproduction

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Comparatively, little data are available detailing the geographic variation that exists in the reproductive endocrinology of adult alligators, especially those living in barrier islands. The Merritt Island National Wildlife Refuge (MI) is a unique barrier island environment and home to the Kennedy Space Center (FL, USA). Seasonal patterns of sex steroids were assessed in adult female American alligators from MI monthly from 2008 to 2009, with additional samples collected at more random intervals in 2006, 2007, and 2010. Plasma 17b-estradiol and vitellogenin concentrations peaked in April, coincident with courtship and mating, and showed patterns similar to those observed in adult female alligators in other regions. Plasma concentrations of progesterone, however, showed patterns distinctly different than those reported for alligator populations in other regions and remained relatively constant throughout the year. Plasma DHEA peaked in July around the time of oviposition, decreased in August, and then remained constant for the remaining months, except for a moderate increase in October. Circulating concentrations of DHEA have not been previously assessed in a female crocodilian, and plasma concentrations coincident with reproductive activity suggest a reproductive and/or behavioral role. Interestingly, plasma testosterone concentrations peaked in May of 2008, as has been shown in female alligator populations in other regions, but showed no peak in 2009, demonstrating dramatic variability from year to year. Surveys showed 2009 to be particularly depauperate of alligator nests in MI, and it is possible that testosterone could serve as a strong indicator of breeding success.

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“…TOXLET 8730 1-7 BDE-47 increased androgen secretion by directly enhancing the expression and activity of 17␤-hydroxysteroid dehydrogenase (17␤-HSD) (Karpeta et al, 2011), whereas 5-hydroxy-2,2 ,4, 4-tetrabromodiphenyl ether (5-OH-BDE-47) and 6-hydroxy-2,2 ,4,4 -tetrabromodiphenyl ether (6-OH-BDE-47) stimulated estradiol secretion by stimulating aromatase expression and activity (Karpeta et al, 2013).…”

Section: G Modelmentioning

confidence: 99%

“…The medium was then changed to M199 with 5% FBS and the cells were cultured for an additional 3, 6, 24 and 48 h with 50 ng/ml of BDE-47, 5-OH-or 6-OH-BDE-47. The dose of reagents was chosen based on our previously published studies (Karpeta et al, 2011(Karpeta et al, , 2012(Karpeta et al, , 2013. In these dose dependent studies we showed that BDE-47 in a dose of 50 ng/ml was the most potent for stimulation of testosterone secretion and CYP2B1 activity (Karpeta et al, 2011(Karpeta et al, , 2012 and metabolites were the most potent for stimulation of estradiol secretion (Karpeta et al, 2013).…”

Section: Cell Culturementioning

confidence: 99%

Different action of 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) and its hydroxylated metabolites on ERα and ERβ gene and protein expression

2014

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Congener-specific action of PBDEs on steroid secretion, CYP17, 17β-HSD and CYP19 activity and protein expression in porcine ovarian follicles

Cited by 30 publications

References 25 publications

In vitro biotransformation of PBDEs by root crude enzyme extracts: Potential role of nitrate reductase (NaR) and glutathione S-transferase (GST) in their debromination

In vitro biotransformation of PBDEs by root crude enzyme extracts: Potential role of nitrate reductase (NaR) and glutathione S-transferase (GST) in their debromination

The reproductive hormone cycle of adult female American alligators from a barrier island population

Different action of 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) and its hydroxylated metabolites on ERα and ERβ gene and protein expression

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