Two waves of transcriptomic changes in periovulatory human granulosa cells.

Area of Science:

• Reproductive Biology and Endocrinology
• Genomics and Transcriptomics
• Ovarian Physiology

Background:

• Granulosa cell (GC) transcriptomic profiling is crucial for understanding the essential crosstalk between GCs and the oocyte during ovulation and oocyte maturation.
• Detailed transcriptional changes in human GCs during ovulation have not been previously assessed.

Purpose of the Study:

• To investigate the dynamic changes in the human granulosa cell transcriptome during the ovulatory process.
• To identify key genes, pathways, and upstream regulators involved in human ovulation.

Main Methods:

• Prospective cohort study of 50 women undergoing fertility treatment.
• GC samples collected at five time points after ovulation induction (OI) (0, 12, 17, 32, and 36 hours).
• Gene expression analyzed by microarray, with differential expression assessed by ANOVA and pathway enrichment analysis.

Main Results:

• Two major transcriptional peaks observed at 12 and 36 hours post-OI, dominated by inflammatory system genes.
• Downregulated genes were associated with cell cycle and DNA repair pathways.
• Upregulated genes at 12 hours indicated inflammatory response initiation, while 36 hours showed effector functions like angiogenesis and tissue remodeling.

Conclusions:

• Human ovulation involves significant dynamic changes in GC gene expression, with two distinct inflammatory-driven peaks.
• Identified upstream regulators and differentially expressed genes may serve as potential pharmaceutical targets for fertility treatments.
• The study provides a valuable, publicly available dataset for future research into human ovarian function.