17β-Estradiol alters oxidative stress response protein expression and oxidative damage in the uterus

Area of Science:

• Reproductive Endocrinology
• Molecular Biology
• Oxidative Stress Research

Background:

• The steroid hormone 17β-estradiol (E2) significantly impacts uterine function, promoting cell proliferation and metabolism.
• Increased cellular activity driven by E2 leads to elevated production of reactive oxygen species (ROS), a key component of oxidative stress.
• Understanding the balance of oxidative stress response proteins is crucial for comprehending uterine health and disease.

Purpose of the Study:

• To investigate the effect of E2 on the expression of key oxidative stress response proteins in the uterus.
• To determine how E2 influences the mRNA and protein levels of thioredoxin (Trx), Cu/Zn superoxide dismutase (SOD1), apurinic endonuclease (Ape1), and protein disulfide isomerase (PDI).
• To explore the potential long-term consequences of E2-induced oxidative stress changes on endometrial health and carcinogenesis.

Main Methods:

• Ovariectomized C57BL/6J female mice were treated with E2.
• Quantitative real-time PCR was used to measure mRNA expression levels of target proteins.
• Western blotting was employed to assess protein expression levels.
• Markers of cellular damage, including lipid peroxidation and protein carbonylation, were quantified.

Main Results:

• E2 treatment significantly increased both mRNA and protein levels of thioredoxin (Trx).
• Conversely, E2 administration led to decreased mRNA and protein expression of SOD1 and Ape1.
• While PDI protein levels were elevated by E2, its transcript levels remained unaffected.
• Significant increases in lipid peroxidation and protein carbonylation were observed following E2 treatment.

Conclusions:

• E2 exerts differential effects on the expression of key oxidative stress-related proteins in the uterus.
• The downregulation of SOD1 and Ape1 by E2 may impair the uterus's ability to regulate ROS effectively.
• These findings suggest a potential role for E2-mediated disruption of oxidative stress balance in the development of endometrial carcinogenesis.