HMGB1-RAGE signaling pathway in pPROM.

Area of Science:

• Obstetrics and Gynecology
• Immunology
• Molecular Biology

Background:

• Placental inflammation is a known risk factor for preterm premature rupture of membranes (pPROM).
• High-mobility group box 1 (HMGB1) is an inflammatory cytokine involved in various pathophysiological processes.
• The HMGB1-RAGE signaling pathway's role in pPROM remains to be fully elucidated.

Purpose of the Study:

• To investigate the role of the HMGB1-RAGE signaling pathway in the mechanisms underlying pPROM.
• To analyze the expression and localization of key components of the HMGB1-RAGE pathway in placental tissues and maternal serum from women with pPROM.

Main Methods:

• Real-time PCR was used to quantify mRNA levels of HMGB1, RAGE, NF-κBp65, MMP-9, and MMP-2 in placental tissues from normal term, PROM, and pPROM groups.
• Western blot analysis was performed to determine protein levels of these markers in placental specimens.
• Immunohistochemistry was employed to assess the cellular localization of HMGB1, RAGE, and NF-κBp65.
• ELISA was utilized to measure serum concentrations of these markers in maternal and cord blood.

Main Results:

• Elevated mRNA and protein expressions of HMGB1, RAGE, NF-κBp65, MMP-9, and MMP-2 were observed in placentas from women with pPROM compared to controls.
• HMGB1 and RAGE showed increased immunoreactivity in placental cells, with NF-κBp65 enhanced in the nucleus of specific cell types in pPROM placentas.
• Maternal serum levels of HMGB1, RAGE, NF-κBp65, MMP-9, and MMP-2 were significantly higher in the pPROM group.

Conclusions:

• The HMGB1-RAGE signaling pathway, involving HMGB1 nuclear-cytoplasmic translocation and subsequent NF-κBp65 activation, appears to play a significant role in pPROM pathogenesis.
• This pathway contributes to pPROM by inducing the release of MMP-9 and MMP-2, leading to placental tissue remodeling.