Pre-pregnancy exposure to fine particulate matter (PM2.5) increases reactive oxygen species production in oocytes and...

Area of Science:

• Environmental Health
• Reproductive Toxicology
• Developmental Biology

Background:

• Fine particulate matter (PM2.5) exposure prior to pregnancy is linked to adverse reproductive outcomes.
• Understanding the specific impacts of PM2.5 on female fertility and early embryonic development is crucial.

Purpose of the Study:

• To investigate the effects of PM2.5 exposure on female mouse fertility and oocyte quality.
• To explore the molecular mechanisms underlying PM2.5-induced reproductive toxicity.

Main Methods:

• Female C57BL/6 mice were exposed to concentrated PM2.5 or filtered air for 12 weeks.
• Oocyte quality was assessed by measuring anti-Müllerian hormone and reactive oxygen species (ROS) levels.
• Fertility parameters, including oocyte degeneration, 2-cell formation rates, litter size, and offspring weight, were evaluated.
• RNA sequencing was performed for transcriptome profiling of oocytes and blastocysts.

Main Results:

• PM2.5 exposure significantly decreased anti-Müllerian hormone levels and increased ROS production in oocytes.
• Oocyte degeneration rates increased, while 2-cell formation rates decreased following PM2.5 exposure.
• Transcriptome analysis revealed dysregulation of genes involved in mitochondrial respiration and metabolic processes.
• Litter size and offspring weight were significantly reduced in the PM2.5-exposed group.

Conclusions:

• Pre-pregnancy exposure to PM2.5 adversely affects female fertility in mice.
• Increased ROS production in oocytes and metabolic disturbances in embryos are potential mechanisms for PM2.5-induced reproductive harm.
• Further research is needed to establish a definitive cause-effect relationship.