Menstruation: induction by matrix metalloproteinases and inflammatory cells

Area of Science:

• Reproductive biology
• Cellular and Molecular Biology
• Immunology

Background:

• Menstruation follows progesterone decline after corpus luteum demise.
• Matrix metalloproteinases (MMPs) play a key role in menstruation.
• Focal expression patterns suggest local, not hormonal, regulation of MMPs.

Purpose of the Study:

• To review the role of MMPs and inflammatory processes in menstruation.
• To examine the relationship between hemopoietic cells and local MMP production.
• To propose regulatory circuits involved in endometrial tissue breakdown.

Main Methods:

• Literature review focusing on menstruation, MMPs, and immune cells.
• Analysis of the interaction between migratory cells and endometrial stromal/epithelial cells.
• Examination of progesterone withdrawal as an initial trigger.

Main Results:

• Menstruation shares similarities with inflammatory processes.
• Hemopoietic cells (mast cells, eosinophils, neutrophils, macrophages) are involved in local MMP production and activation.
• Progesterone withdrawal initiates regulatory circuits involving cell interactions and molecular signaling.

Conclusions:

• Local regulation, involving immune cells and MMPs, is central to menstruation.
• Interactions between migratory and endometrial cells drive tissue degradation.
• These mechanisms explain the focal nature of endometrial breakdown during menstruation.