The sensitivity of the DNA damage checkpoint prevents oocyte maturation in endometriosis

Area of Science:

• Reproductive biology
• Cellular stress response
• Endocrinology

Background:

• Mouse oocytes arrest in meiosis I due to DNA damage, involving the Spindle Assembly Checkpoint (SAC) and DNA Damage Response (DDR) pathways.
• The sensitivity of these pathways to physiological levels of DNA damage remains unclear.
• Endometriosis affects 10% of women, often linked to reduced fertility.

Purpose of the Study:

• To investigate if DNA damage is the primary trigger for oocyte meiotic arrest.
• To determine the role of reactive oxygen species (ROS) in endometriosis-associated oocyte dysfunction.
• To explore potential therapeutic interventions for endometriosis-related infertility.

Main Methods:

• Exposure of mouse oocytes to follicular fluid from endometriosis patients and controls.
• Assessment of DNA damage, ROS levels, and activation of the DDR-SAC pathway (including ATM kinase).
• Evaluation of meiotic progression following treatment with ROS scavengers.

Main Results:

• Follicular fluid from endometriosis patients, but not controls, elevated ROS levels and induced DNA damage in oocytes.
• This damage activated the DDR-SAC pathway, leading to metaphase I arrest.
• Administration of ROS scavengers restored meiosis I completion, identifying ROS as the primary trigger.

Conclusions:

• Reactive oxygen species in follicular fluid from endometriosis patients are a primary cause of oocyte meiotic arrest.
• This study establishes a clinical link between the DDR-SAC pathway and endometriosis-related infertility.
• ROS scavenging presents a novel therapeutic strategy for improving fertility in women with endometriosis.