The effects of iodoacetic acid on the mouse ovary

Fields, Audrey

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https://hdl.handle.net/2142/129777 Copy

Description

Title

The effects of iodoacetic acid on the mouse ovary

Author(s)

Fields, Audrey

Issue Date

2025-05-06

Director of Research (if dissertation) or Advisor (if thesis)

de Mejia, Elvira

Doctoral Committee Chair(s)

Flaws, Jodi A

Committee Member(s)

Ziv-Gal, Ayelet

Department of Study

Nutritional Sciences

Discipline

Nutritional Sciences

Degree Granting Institution

University of Illinois Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• Iodoacetic Acid (IAA)
• Oxidative stress
• Water disinfection byproducts (DBP)

Abstract

The incorporation of water disinfectants into the main water supply has significantly decreased the presence of waterborne diseases such as cholera. However, the interaction between disinfectants and organic material generates water disinfection byproducts (DBPs). Iodoacetic acid (IAA) is an unregulated DBP that has been reported as a reproductive toxicant. Our previous studies show that IAA inhibits follicle growth and alters the expression of steroidogenic factors in vitro, but its underlying mechanisms of action were unknown. Thus, both an in vivo experiments and in vitro experiments were conducted to test the hypothesis that IAA exposure causes ovarian toxicity by altering gene expression of oxidative stress markers in the mouse ovary. To test the hypothesis in vitro, ovarian antral follicles were collected from CD-1 mice between 40 and 42 days of age. The follicles were incubated in individual wells within a 96-well plate in media containing vehicle control (water) or IAA (2µM, 5µM, 10µM, 15µM) for 96 hours. At 0 hours, 24 hours, 48 hours, 72 hours, and 96 hours, follicle growth was measured over the 96-hour period. Following the 96-hour incubation, follicles were collected, RNA was extracted, reverse transcribed, and subjected to quantitative polymerase chain reaction (qPCR) to analyze the expression of glutathione markers (Gpx1, Gpx2, Gsr, Gss, Gsta1, Gstm1, Gsto1, Gstp1 Gstt1), superoxide dismutase markers (Sod1, Sod2), and apoptosis markers (Bax, Bcl2), and catalase. IAA exposure significantly increased expression of Gpx1 in the 5µM treatment group compared to control and increased Gsto1 in the 10µM and 15µM treatment groups when compared to control. IAA exposure did not alter Gpx2, Gsr, Gsta1, Gstm1, Gstp1, Gstt1, Sod1, Sod2, Cat, Bax, or Bcl2 expression compared to control. Following the results of the in vitro study, an additional hypothesis was tested regarding the potential rescuing of follicular growth and gene expression of oxidative stress and apoptosis markers in IAA-treated ovarian antral follicles due to the incorporation of an antioxidant in vitro. To test this hypothesis, ovarian antral follicles were collected from CD-1 mice between 40 and 42 days of age. The follicles were incubated in individual wells within a 96-well plate in media containing either a control (water), IAA (10µM), Trolox (5µM), or IAA (10µM) + Trolox (5µM) for 96 hours. At 0 hours, 24 hours, 48 hours, 72 hours, and 96 hours and follicle growth was measured over the 96-hour period. Following the 96-hour incubation, follicles were collected, RNA was extracted, reverse transcribed, and subjected to quantitative polymerase chain reaction (qPCR) to analyze the expression of glutathione markers (Gpx1, Gpx2, Gsr, Gss, Gsta1, Gstm1, Gsto1, Gstp1 Gstt1), superoxide dismutase markers (Sod1, Sod2), and apoptosis markers (Bax, Bcl2), and catalase. IAA exposure significantly increased expression of Gsto1 for the IAA (10µM) and the IAA (10µM) + Trolox (5µM) treatment groups when compared to control. IAA exposure did not alter Gpx1, Gpx2, Gsr, Gsta1, Gstm1, Gstp1, Gstt1, Sod1, Sod2, Cat, Bax, or Bcl2 expression compared to control. To test the hypothesis that IAA induces oxidative stress in the ovary in vivo, adult CD-1 mice were dosed with either water (control) or IAA (2.69, 53.78, 538.14, or 2,695.71µM) in their drinking water for 35 days. Following this, ovaries were collected when the mice were in diestrus, RNA was extracted, reverse transcribed, and subjected to quantitative polymerase chain reaction (qPCR) to analyze the expression of glutathione markers (Gpx1, Gpx2, Gsr, Gss, Gsta1, Gstm1, Gsto1, Gstp1 Gstt1), superoxide dismutase markers (Sod1, Sod2), and apoptosis markers (Bax, Bcl2), and catalase. IAA exposure decreased the expression of Bcl2 in the 2.69 µM, 53.78 µM, 538.14 µM, and 2,695.71µM treatment groups compared to control and it decreased the expression of Cat in the 2.69 µM, 53.78 µM, 538.14 µM and 2,695.71µM treatment groups compared to control. In addition, IAA significantly decreased the expression of Sod1 in the 2.69 µM, 53.78 µM and 538.14 µM IAA treatment groups compared to control, but it did not affect the expression of Sod2 compared to control. IAA exposure decreased expression of Gss in the 2.69 µM and 2,695.71µM treatment groups compared to control, Gsta1 in the 2.69 µM and 53.78 µM treatment groups compared to control, Gstp1 in the 53.78 µM treatment group compared to control, and Gstt1 in the 2.69 µM, 53.78 µM, and 2,695.71µM treatment groups compared to control. IAA exposure did not alter Gpx1, Gpx2, or Gsr compared to control. IAA exposure increased expression of Bax in the 53.78 µM, 538.14 µM, and 2,695.71µM treatment groups compared to control. IAA exposure increased expression of Gstm1 in the 53.78 µM, 538.14 µM, and 2,695.71µM treatment groups compared to control. Collectively, the data from this thesis project indicate that IAA exposure causes ovarian toxicity by altering oxidative stress pathways in the mouse ovary.

Graduation Semester

2025-05

Type of Resource

Thesis

Handle URL

https://hdl.handle.net/2142/129777

Copyright and License Information

Copyright 2025 Audrey Fields

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