Brain microvascular endothelial cells: Beyond a barrier.

Area of Science:

• Neuroscience
• Immunology
• Cell Biology

Background:

• The blood-brain barrier (BBB) was traditionally viewed as a passive filter.
• Brain microvascular endothelial cells (BMECs) form the structural basis of the BBB.
• Emerging evidence suggests BMECs have active roles in brain immunity.

Purpose of the Study:

• To re-evaluate the role of BMECs within the neurovascular unit.
• To highlight BMECs as dynamic immunoregulatory sentinels.
• To explore BMEC involvement in central nervous system disorders.

Main Methods:

• Review of current literature on BBB and BMEC function.
• Analysis of signaling pathways (e.g., Wnt/β-catenin, NF-κB) in BMECs.
• Examination of BMEC interactions with immune cells and inflammatory signals.

Main Results:

• BMECs actively sense and respond to inflammatory and pathogenic signals.
• BMECs integrate signaling pathways to balance barrier integrity and immune defense.
• Dysfunctional BMECs contribute to neuroinflammation and barrier breakdown in CNS disorders like stroke, Alzheimer's disease, and multiple sclerosis.

Conclusions:

• BMECs are active participants in brain immunity, not just passive structural components.
• Targeting BMEC immunoregulatory functions presents novel therapeutic strategies for neurological diseases.
• Further research is needed to address endothelial heterogeneity and develop precise interventions.