TY - JOUR
T1 - Di (2-ethylhexyl) phthalate inhibits growth of mouse ovarian antral follicles through an oxidative stress pathway
AU - Wang, Wei
AU - Craig, Zelieann R.
AU - Basavarajappa, Mallikarjuna S.
AU - Gupta, Rupesh K.
AU - Flaws, Jodi A.
N1 - Funding Information:
The authors thank Liying Gao for her outstanding technical help. This work was supported by the National Institutes of Health (NIH) R01ES019178 (JAF), a Billie Field Fellowship in Reproductive Biology (WW and ZRC) and an Environmental Toxicology Scholarship (MSB).
PY - 2012/1/15
Y1 - 2012/1/15
N2 - Di (2-ethylhexyl) phthalate (DEHP) is a plasticizer that has been shown to inhibit growth of mouse antral follicles, however, little is known about the mechanisms by which DEHP does so. Oxidative stress has been linked to follicle growth inhibition as well as phthalate-induced toxicity in non-ovarian tissues. Thus, we hypothesized that DEHP causes oxidative stress and that this leads to inhibition of the growth of antral follicles. To test this hypothesis, antral follicles isolated from CD-1 mice (age 31-35. days) were cultured with vehicle control (dimethylsulfoxide [DMSO]) or DEHP (1-100μg/ml) ± N-acetyl cysteine (NAC, an antioxidant at 0.25-1. mM). During culture, follicles were measured daily. At the end of culture, follicles were collected and processed for in vitro reactive oxygen species (ROS) assays to measure the presence of free radicals or for measurement of the expression and activity of various key antioxidant enzymes: Cu/Zn superoxide dismutase (SOD1), glutathione peroxidase (GPX) and catalase (CAT). The results indicate that DEHP inhibits the growth of follicles compared to DMSO control and that NAC (0.25-1. mM) blocks the ability of DEHP to inhibit follicle growth. Furthermore, DEHP (10μg/ml) significantly increases ROS levels and reduces the expression and activity of SOD1 compared to DMSO controls, whereas NAC (0.5. mM) rescues the effects of DEHP on ROS levels and SOD1. However, the expression and activity of GPX and CAT were not affected by DEHP treatment. Collectively, these data suggest that DEHP inhibits follicle growth by inducing production of ROS and by decreasing the expression and activity of SOD1.
AB - Di (2-ethylhexyl) phthalate (DEHP) is a plasticizer that has been shown to inhibit growth of mouse antral follicles, however, little is known about the mechanisms by which DEHP does so. Oxidative stress has been linked to follicle growth inhibition as well as phthalate-induced toxicity in non-ovarian tissues. Thus, we hypothesized that DEHP causes oxidative stress and that this leads to inhibition of the growth of antral follicles. To test this hypothesis, antral follicles isolated from CD-1 mice (age 31-35. days) were cultured with vehicle control (dimethylsulfoxide [DMSO]) or DEHP (1-100μg/ml) ± N-acetyl cysteine (NAC, an antioxidant at 0.25-1. mM). During culture, follicles were measured daily. At the end of culture, follicles were collected and processed for in vitro reactive oxygen species (ROS) assays to measure the presence of free radicals or for measurement of the expression and activity of various key antioxidant enzymes: Cu/Zn superoxide dismutase (SOD1), glutathione peroxidase (GPX) and catalase (CAT). The results indicate that DEHP inhibits the growth of follicles compared to DMSO control and that NAC (0.25-1. mM) blocks the ability of DEHP to inhibit follicle growth. Furthermore, DEHP (10μg/ml) significantly increases ROS levels and reduces the expression and activity of SOD1 compared to DMSO controls, whereas NAC (0.5. mM) rescues the effects of DEHP on ROS levels and SOD1. However, the expression and activity of GPX and CAT were not affected by DEHP treatment. Collectively, these data suggest that DEHP inhibits follicle growth by inducing production of ROS and by decreasing the expression and activity of SOD1.
KW - Antral follicles
KW - Di (2-ethylhexyl) phthalate
KW - Ovary
KW - Oxidative stress
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U2 - 10.1016/j.taap.2011.11.008
DO - 10.1016/j.taap.2011.11.008
M3 - Article
C2 - 22155089
AN - SCOPUS:84855782737
SN - 0041-008X
VL - 258
SP - 288
EP - 295
JO - Toxicology and Applied Pharmacology
JF - Toxicology and Applied Pharmacology
IS - 2
ER -