COMPENDIUM ON FUNCTIONAL MEDICINE - Flipbook - Page 591
Cellular Components of the BBB
The BBB consists of specialized cell types that together form the
neurovascular unit (NVU):
Brain Microvascular Endothelial Cells
The primary cellular component featuring tight junctions that
restrict paracellular transport [11, 12]
Astrocytes
Their endfeet surround capillaries and release factors that
maintain barrier integrity [13, 14]
Pericytes
Contractile cells that regulate capillary diameter, BBB
development, and maintenance [15, 16]
Microglia
Resident immune cells that respond to barrier disruption and can
contribute to restoration or further damage [17, 18]
Neurons
Neuronal activity influences BBB function through neurovascular
coupling [19, 20]
Molecular Structure of Tight Junctions
Tight junctions between endothelial cells represent the anatomical
foundation of the BBB, comprising:
Claudin Family Proteins
Particularly Claudin-5, the most enriched tight junction protein in
brain endothelium, critical for restricting paracellular permeability
[21, 22]
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