M1 Monocyte Polarization and Deficient Immunomodulation in Preeclampsia

Area of Science:

• Obstetrics and Gynecology
• Immunology
• Molecular Biology

Background:

• Preeclampsia (PE) is a pregnancy syndrome linked to systemic inflammation, potentially involving damage-associated molecular patterns (DAMPs).
• High mobility group Box 1 (HMGB1) is a DAMP that interacts with haptoglobin and is cleared by the CD163 receptor.

Purpose of the Study:

• To investigate the roles of haptoglobin, HMGB1, and the CD163 receptor in the inflammatory response in preeclamptic pregnancies.
• To compare monocyte surface receptor expression and intracellular protein levels between women with and without preeclampsia.

Main Methods:

• Monocytes from preeclamptic and normotensive pregnant women were analyzed for TLR4, RAGE, CD64, and CD163 receptors via flow cytometry.
• Intracellular haptoglobin and HMGB1 expression in monocytes was assessed.
• Plasma levels of haptoglobin, HMGB1, hemeoxygenase-1, and cytokines were measured using ELISA.

Main Results:

• Monocytes from preeclamptic women showed higher expression of TLR4, CD64, RAGE, intracellular HMGB1, and haptoglobin compared to normotensive controls.
• Extracellular CD163 expression on monocytes was lower in preeclamptic women.
• Plasma HMGB1, TNF-α, IL-1β, and IL-6 were elevated, while haptoglobin, hemeoxygenase-1, and IL-10 were decreased in preeclampsia.

Conclusions:

• Monocytes in preeclampsia exhibit an M1-like inflammatory profile due to increased inflammatory cytokines and specific receptor expression.
• Reduced CD163 expression and lower haptoglobin levels in preeclampsia indicate impaired regulation of the inflammatory process.