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Effects of Common Pesticides on Prostaglandin D2 (PGD2) Inhibition in SC5 Mouse Sertoli Cells, Evidence of Binding at the COX-2 Active Site, and Implications for Endocrine Disruption.

Kugathas S, Audouze K, Ermler S, Orton F, Rosivatz E, Scholze M, Kortenkamp A - Environ. Health Perspect. (2015)

Bottom Line: Many endocrine-disrupting chemicals have been found to suppress prostaglandin synthesis, but to our knowledge, pesticides have never been tested for these effects.Supplementation with AA failed to reverse this effect, suggesting that the sites of action of these pesticides are COX enzymes.Kugathas S, Audouze K, Ermler S, Orton F, Rosivatz E, Scholze M, Kortenkamp A. 2016.

View Article: PubMed Central - PubMed

Affiliation: Institute of Environment, Health and Societies, Brunel University London, Uxbridge, United Kingdom.

ABSTRACT

Background: There are concerns that diminished prostaglandin action in fetal life could increase the risk of congenital malformations. Many endocrine-disrupting chemicals have been found to suppress prostaglandin synthesis, but to our knowledge, pesticides have never been tested for these effects.

Objectives: We assessed the ability of pesticides that are commonly used in the European Union to suppress prostaglandin D2 (PGD2) synthesis.

Methods: Changes in PGD2 secretion in juvenile mouse Sertoli cells (SC5 cells) were measured using an ELISA. Coincubation with arachidonic acid (AA) was conducted to determine the site of action in the PGD2 synthetic pathway. Molecular modeling studies were performed to assess whether pesticides identified as PGD2-active could serve as ligands of the cyclooxygenase-2 (COX-2) binding pocket.

Results: The pesticides boscalid, chlorpropham, cypermethrin, cyprodinil, fenhexamid, fludioxonil, imazalil (enilconazole), imidacloprid, iprodione, linuron, methiocarb, o-phenylphenol, pirimiphos-methyl, pyrimethanil, and tebuconazole suppressed PGD2 production. Strikingly, some of these substances-o-phenylphenol, cypermethrin, cyprodinil, linuron, and imazalil (enilconazole)-showed potencies (IC50) in the range between 175 and 1,500 nM, similar to those of analgesics intended to block COX enzymes. Supplementation with AA failed to reverse this effect, suggesting that the sites of action of these pesticides are COX enzymes. The molecular modeling studies revealed that the COX-2 binding pocket can accommodate most of the pesticides shown to suppress PGD2 synthesis. Some of these pesticides are also capable of antagonizing the androgen receptor.

Conclusions: Chemicals with structural features more varied than previously thought can suppress PGD2 synthesis. Our findings signal a need for in vivo studies to establish the extent of endocrine-disrupting effects that might arise from simultaneous interference with PGD2 signaling and androgen action.

Citation: Kugathas S, Audouze K, Ermler S, Orton F, Rosivatz E, Scholze M, Kortenkamp A. 2016. Effects of common pesticides on prostaglandin D2 (PGD2) inhibition in SC5 mouse Sertoli cells, evidence of binding at the COX-2 active site, and implications for endocrine disruption. Environ Health Perspect 124:452-459; http://dx.doi.org/10.1289/ehp.1409544.

No MeSH data available.


Related in: MedlinePlus

The influence of AA supplementation on the PGD2-suppressing effects of selected pesticides. Abbreviations with IC80 given in parentheses: AA, arachidonic acid; bos, boscalid, (20 μM); cpro, chlorpropham, (10 μM); cyp, cyprodinil, (10 μM); cypm, cypermethrin, (10 μM); imid, imidacloprid, (50 μM); imz, imazalil (enilconazole), (10 μM); lin, linuron, (10 μM); pmeth, pirimiphos-methyl, (50 μM); teb, tebuconazole, (50 μM). PGD2 levels in mouse Sertoli cells exposed for 24 hr to pesticides at concentrations producing 80% suppression of PGD2 synthesis, with and without arachidonic acid (AA) supplementation. Comparisons are made with cells that received AA (10 μM) for 2 hr after 22 hr of exposure to pesticide. The means of 3 experiments are shown; error bars represent standard deviations.
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f3: The influence of AA supplementation on the PGD2-suppressing effects of selected pesticides. Abbreviations with IC80 given in parentheses: AA, arachidonic acid; bos, boscalid, (20 μM); cpro, chlorpropham, (10 μM); cyp, cyprodinil, (10 μM); cypm, cypermethrin, (10 μM); imid, imidacloprid, (50 μM); imz, imazalil (enilconazole), (10 μM); lin, linuron, (10 μM); pmeth, pirimiphos-methyl, (50 μM); teb, tebuconazole, (50 μM). PGD2 levels in mouse Sertoli cells exposed for 24 hr to pesticides at concentrations producing 80% suppression of PGD2 synthesis, with and without arachidonic acid (AA) supplementation. Comparisons are made with cells that received AA (10 μM) for 2 hr after 22 hr of exposure to pesticide. The means of 3 experiments are shown; error bars represent standard deviations.

Mentions: According to our concentration–response analyses (Figure 1 and Table 1; see also Supplemental Material, Figure S2), the next nine most potent PGD2-active agents after OPP were boscalid, chlorpropham, cypermethrin, cyprodinil, imazalil (enilconazole), imidacloprid, linuron, pirimiphos-methyl, and tebuconazole. These agents were chosen to analyze the effects of AA supplementation (for 2 hr) following 22 hr of exposure. Each of these pesticides was administered to SC5 cells at a concentration producing 80% PGD2 suppression relative to solvent controls. In all cases, the addition of AA had no effects on PGD2 suppression (Figure 3), again suggesting that the mode of action is inhibition of COX isoforms. We attempted to corroborate this directly by performing COX activity assays (Cayman 700200, 760151) but found that these assays were insufficiently sensitive for the number of cells used in the SC5 assay. We therefore conducted molecular modeling studies of binding to the COX-2 active site to further investigate the likelihood of COX inhibition.


Effects of Common Pesticides on Prostaglandin D2 (PGD2) Inhibition in SC5 Mouse Sertoli Cells, Evidence of Binding at the COX-2 Active Site, and Implications for Endocrine Disruption.

Kugathas S, Audouze K, Ermler S, Orton F, Rosivatz E, Scholze M, Kortenkamp A - Environ. Health Perspect. (2015)

The influence of AA supplementation on the PGD2-suppressing effects of selected pesticides. Abbreviations with IC80 given in parentheses: AA, arachidonic acid; bos, boscalid, (20 μM); cpro, chlorpropham, (10 μM); cyp, cyprodinil, (10 μM); cypm, cypermethrin, (10 μM); imid, imidacloprid, (50 μM); imz, imazalil (enilconazole), (10 μM); lin, linuron, (10 μM); pmeth, pirimiphos-methyl, (50 μM); teb, tebuconazole, (50 μM). PGD2 levels in mouse Sertoli cells exposed for 24 hr to pesticides at concentrations producing 80% suppression of PGD2 synthesis, with and without arachidonic acid (AA) supplementation. Comparisons are made with cells that received AA (10 μM) for 2 hr after 22 hr of exposure to pesticide. The means of 3 experiments are shown; error bars represent standard deviations.
© Copyright Policy - public-domain
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4829986&req=5

f3: The influence of AA supplementation on the PGD2-suppressing effects of selected pesticides. Abbreviations with IC80 given in parentheses: AA, arachidonic acid; bos, boscalid, (20 μM); cpro, chlorpropham, (10 μM); cyp, cyprodinil, (10 μM); cypm, cypermethrin, (10 μM); imid, imidacloprid, (50 μM); imz, imazalil (enilconazole), (10 μM); lin, linuron, (10 μM); pmeth, pirimiphos-methyl, (50 μM); teb, tebuconazole, (50 μM). PGD2 levels in mouse Sertoli cells exposed for 24 hr to pesticides at concentrations producing 80% suppression of PGD2 synthesis, with and without arachidonic acid (AA) supplementation. Comparisons are made with cells that received AA (10 μM) for 2 hr after 22 hr of exposure to pesticide. The means of 3 experiments are shown; error bars represent standard deviations.
Mentions: According to our concentration–response analyses (Figure 1 and Table 1; see also Supplemental Material, Figure S2), the next nine most potent PGD2-active agents after OPP were boscalid, chlorpropham, cypermethrin, cyprodinil, imazalil (enilconazole), imidacloprid, linuron, pirimiphos-methyl, and tebuconazole. These agents were chosen to analyze the effects of AA supplementation (for 2 hr) following 22 hr of exposure. Each of these pesticides was administered to SC5 cells at a concentration producing 80% PGD2 suppression relative to solvent controls. In all cases, the addition of AA had no effects on PGD2 suppression (Figure 3), again suggesting that the mode of action is inhibition of COX isoforms. We attempted to corroborate this directly by performing COX activity assays (Cayman 700200, 760151) but found that these assays were insufficiently sensitive for the number of cells used in the SC5 assay. We therefore conducted molecular modeling studies of binding to the COX-2 active site to further investigate the likelihood of COX inhibition.

Bottom Line: Many endocrine-disrupting chemicals have been found to suppress prostaglandin synthesis, but to our knowledge, pesticides have never been tested for these effects.Supplementation with AA failed to reverse this effect, suggesting that the sites of action of these pesticides are COX enzymes.Kugathas S, Audouze K, Ermler S, Orton F, Rosivatz E, Scholze M, Kortenkamp A. 2016.

View Article: PubMed Central - PubMed

Affiliation: Institute of Environment, Health and Societies, Brunel University London, Uxbridge, United Kingdom.

ABSTRACT

Background: There are concerns that diminished prostaglandin action in fetal life could increase the risk of congenital malformations. Many endocrine-disrupting chemicals have been found to suppress prostaglandin synthesis, but to our knowledge, pesticides have never been tested for these effects.

Objectives: We assessed the ability of pesticides that are commonly used in the European Union to suppress prostaglandin D2 (PGD2) synthesis.

Methods: Changes in PGD2 secretion in juvenile mouse Sertoli cells (SC5 cells) were measured using an ELISA. Coincubation with arachidonic acid (AA) was conducted to determine the site of action in the PGD2 synthetic pathway. Molecular modeling studies were performed to assess whether pesticides identified as PGD2-active could serve as ligands of the cyclooxygenase-2 (COX-2) binding pocket.

Results: The pesticides boscalid, chlorpropham, cypermethrin, cyprodinil, fenhexamid, fludioxonil, imazalil (enilconazole), imidacloprid, iprodione, linuron, methiocarb, o-phenylphenol, pirimiphos-methyl, pyrimethanil, and tebuconazole suppressed PGD2 production. Strikingly, some of these substances-o-phenylphenol, cypermethrin, cyprodinil, linuron, and imazalil (enilconazole)-showed potencies (IC50) in the range between 175 and 1,500 nM, similar to those of analgesics intended to block COX enzymes. Supplementation with AA failed to reverse this effect, suggesting that the sites of action of these pesticides are COX enzymes. The molecular modeling studies revealed that the COX-2 binding pocket can accommodate most of the pesticides shown to suppress PGD2 synthesis. Some of these pesticides are also capable of antagonizing the androgen receptor.

Conclusions: Chemicals with structural features more varied than previously thought can suppress PGD2 synthesis. Our findings signal a need for in vivo studies to establish the extent of endocrine-disrupting effects that might arise from simultaneous interference with PGD2 signaling and androgen action.

Citation: Kugathas S, Audouze K, Ermler S, Orton F, Rosivatz E, Scholze M, Kortenkamp A. 2016. Effects of common pesticides on prostaglandin D2 (PGD2) inhibition in SC5 mouse Sertoli cells, evidence of binding at the COX-2 active site, and implications for endocrine disruption. Environ Health Perspect 124:452-459; http://dx.doi.org/10.1289/ehp.1409544.

No MeSH data available.


Related in: MedlinePlus