Adverse effects of 2-Methoxyestradiol on mouse oocytes during reproductive aging

Area of Science:

• Reproductive biology
• Endocrinology
• Cell biology

Background:

• 2-Methoxyestradiol (2-ME2), a metabolite of 17β-estradiol, is investigated for its antitumor properties.
• Ovarian function and oocyte quality decline with female reproductive aging.
• The role of 2-ME2 in ovarian aging and oocyte health is not fully understood.

Purpose of the Study:

• To investigate the impact of 2-Methoxyestradiol (2-ME2) on mouse oocyte meiotic maturation.
• To explore the relationship between endogenous 2-ME2 levels and ovarian aging.
• To elucidate the cellular mechanisms underlying 2-ME2-induced oocyte dysfunction.

Main Methods:

• In vitro application of 2-ME2 to mouse oocytes.
• Assessment of meiotic progression, spindle structure, and chromosome alignment.
• Measurement of reactive oxygen species (ROS), malondialdehyde, and apoptosis.
• Analysis of mitochondrial dynamics (DRP1, MFN1, Opa1).
• In vivo studies involving intraperitoneal injection of 2-ME2 in mice.

Main Results:

• 2-ME2 exposure arrested oocytes at metaphase I (MI) in a dose-dependent manner.
• Abnormal spindle formation and chromosome alignment were observed.
• 2-ME2 induced increased reactive oxygen species (ROS), malondialdehyde, and apoptosis.
• Mitochondrial dynamics were imbalanced, with increased DRP1 and MFN1, and decreased Opa1.
• Similar effects were seen in oocytes from 2-ME2-injected mice.

Conclusions:

• 2-Methoxyestradiol (2-ME2) impairs oocyte meiotic maturation.
• Mechanisms include induced mitochondrial imbalance, oxidative stress, and apoptosis.
• Stable ovarian 2-ME2 levels may contribute to reduced oocyte quality during aging.