mPR-Specific Actions Influence Maintenance of the Blood-Brain Barrier (BBB)

Area of Science:

• Neuroscience
• Vascular Biology
• Genetics

Background:

• Cerebral cavernous malformations (CCMs) are vascular defects increasing hemorrhagic stroke risk.
• CCMs arise from disrupted CCM signaling complexes (CSCs), compromising blood-brain barrier (BBB) integrity.
• Current understanding lacks early indicators for CCM-related BBB dysfunction.

Purpose of the Study:

• To investigate the role of progesterone receptor (PRG) signaling in CCM pathogenesis.
• To elucidate the interplay between CCM proteins, PRG signaling, and BBB integrity.
• To identify biomarkers for early detection of BBB disruption in CCMs.

Main Methods:

• Investigated CCM gene depletion and mPR-specific PRG actions in vitro (endothelial cells).
• Utilized hemizygous Ccm mutant mice models for in vivo studies.
• Analyzed blood biomarkers associated with BBB disruption.

Main Results:

• Depletion of CCM genes or mPR-specific PRG actions disrupted the CSC-mPRs-PRG (CmP) network.
• This disruption increased endothelial cell permeability in vitro.
• In vivo, CCM gene depletion combined with mPR-specific PRG actions caused BBB disruption and identified predictive blood biomarkers.

Conclusions:

• The study reveals a novel CmP signaling network linking CCMs, PRG signaling, and BBB integrity.
• This provides a mechanistic understanding of CCM-related BBB breakdown.
• Identified potential etiological biomarkers for predicting early hemorrhagic events in CCM patients.