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Updated: Aug 21, 2026
Culture and Co-Culture of Mouse Ovaries and Ovarian Follicles
Published on: March 17, 2015
Methoxychlor induces proliferation of the mouse ovarian surface epithelium
Daniel A Symonds1, Dragana Tomic, Kimberly P Miller
1Program in Toxicology and Department of Epidemiology and Preventive Medicine, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA.
Abstract:
While the pesticide methoxychlor (MXC) has a variety of adverse effects on the female reproductive system, the effects of MXC on the ovarian surface epithelium (OSE) are unknown. Thus, this study tested the hypothesis that MXC alters the growth of the OSE. Mouse OSE cells were isolated by enzymatic digestion and cultured with vehicle, 3 microM of MXC, or 3 microM of 2,2-bis[p-hydroxyphenyl]-1,1,1,-trichloroethane (HPTE) for 14 days. After culture, proliferation and apoptosis were assessed by measurement of cell density, immunohistochemistry, and real-time polymerase chain reaction. Cell density was 66% greater for MXC-treated cells and 95% greater for HPTE-treated cells than controls (p < or = 0.05). The estrogen receptor blocker ICI 182,780 abolished MXC- and HPTE-induced increases in cell density. Proliferating cell nuclear antigen (PCNA) staining was positive in only 22 +/- 2.3% of controls, compared to 35 +/- 2.4% of MXC-treated cells and 40 +/- 2.4% of HPTE-treated cells (p < or = 0.05). The cell cycle regulators, cyclinD2 and cdk4, were significantly increased in MXC- and HPTE-treated cells compared to controls. The ApopTag assay demonstrated apoptotic cells in 4.8 +/- 0.45% of controls, 2.2 +/- 0.56% of MXC-treated cells, and 2.1 +/- 0.33% of HPTE-treated cells (p < or = 0.005). Expression of bcl-2 was significantly increased in MXC- and HPTE-treated cells, while bax was decreased in MXC- and HPTE-treated cells compared to controls. Collectively, these data indicate that MXC and HPTE stimulate OSE cell growth by increasing proliferation and inhibiting apoptosis. Further, since ICI 182,780 blocked MXC- and HPTE-induced OSE growth, these data suggest that the effects of MXC and HPTE on the OSE are mediated by estrogen receptors.
Insights
The pesticide methoxychlor (MXC) and its metabolite HPTE increase ovarian surface epithelium (OSE) cell growth by promoting proliferation and reducing apoptosis. These effects are mediated through estrogen receptors, as shown by blockage with ICI 182,780.
Area of Science:
- Reproductive Toxicology
- Endocrinology
- Cell Biology
Background:
- Methoxychlor (MXC) is a pesticide with known adverse effects on the female reproductive system.
- The impact of MXC on ovarian surface epithelium (OSE) cells, crucial for ovarian function, remains largely uncharacterized.
- Understanding MXC's effects on OSE is vital for assessing its reproductive health risks.
Purpose of the Study:
- To investigate the hypothesis that methoxychlor (MXC) alters the growth of mouse ovarian surface epithelium (OSE) cells.
- To determine the mechanisms underlying MXC's effects on OSE cell proliferation and apoptosis.
- To explore the role of estrogen receptors in mediating MXC's impact on OSE.
Main Methods:
- Isolation and culture of mouse OSE cells.
- Treatment of OSE cells with vehicle, MXC, or its metabolite 2,2-bis[p-hydroxyphenyl]-1,1,1,-trichloroethane (HPTE).
- Assessment of cell proliferation (cell density, PCNA staining, cell cycle regulators) and apoptosis (ApopTag assay, bcl-2, bax expression).
- Evaluation of estrogen receptor involvement using the blocker ICI 182,780.
Main Results:
- MXC and HPTE significantly increased OSE cell density and proliferation, indicated by higher PCNA staining and elevated cyclinD2 and cdk4 levels.
- MXC and HPTE exposure reduced OSE cell apoptosis and altered the expression of apoptosis-related proteins (increased bcl-2, decreased bax).
- The estrogen receptor blocker ICI 182,780 effectively abolished the MXC- and HPTE-induced increases in OSE cell density.
Conclusions:
- Methoxychlor (MXC) and its metabolite HPTE stimulate OSE cell growth by enhancing proliferation and inhibiting apoptosis.
- The observed effects of MXC and HPTE on OSE are mediated through estrogen receptors.
- These findings highlight a potential mechanism for MXC's adverse reproductive effects via OSE disruption.
