Human granulosa cells function as innate immune cells executing an inflammatory reaction during ovulation: a...

Area of Science:

• Reproductive Biology
• Immunology
• Molecular Biology

Background:

• Ovulation has been previously likened to a localized inflammatory response.
• The precise molecular mechanisms driving this inflammatory aspect of ovulation remain incompletely understood.

Purpose of the Study:

• To investigate whether known inflammatory mechanisms are active during human ovulation.
• To identify the specific molecular pathways and genes involved in ovulation-associated inflammation.

Main Methods:

• An in silico study utilizing a unique, PCR-validated transcriptome microarray dataset.
• Paired granulosa cell samples were collected from nine women undergoing fertility treatment, before and 36 hours after ovulation induction.

Main Results:

• A significant upregulation of 259 inflammation-related genes (2-80 fold, p<0.05) was observed during ovulation.
• Key inflammatory signaling pathways identified include NF-κB, MAPK, and JAK/STAT (p<1.0E-10).
• Upregulated genes were involved in eicosanoid production, chemo-attraction, coagulation, cell proliferation, and inflammation resolution.

Conclusions:

• Granulosa cells can independently orchestrate ovulation as a sterile inflammatory reaction.
• The innate immune system is not required for initiating or resolving ovulation-associated inflammation.