Blood-brain barrier endothelial cell surface components

The blood-brain barrier (BBB) endothelial cell surface components are a diverse group of proteins and structural elements that regulate the selective exchange of substances between the blood and the central nervous system (CNS) (NIH). These components include tight junction proteins, such as claudins (e.g., Claudin-5) and occludin, which seal the paracellular space between endothelial cells to prevent the entry of large or hydrophilic molecules (PubMed PMID: 30124131). Additionally, the surface features specialized receptors and transporters, including the transferrin receptor (TfR), insulin receptor (IR), and glucose transporter 1 (GLUT1), which facilitate the transport of essential nutrients and signaling molecules via receptor-mediated transcytosis or carrier-mediated transport (UniProt P02786, P06213). In pathological conditions like Alzheimer's disease and multiple sclerosis, the dysfunction or degradation of these components leads to increased barrier permeability and neuroinflammation (Nature Reviews Neuroscience PMID: 29449713). Conversely, these surface proteins are primary targets for CNS drug delivery strategies, where 'shuttle' molecules like pabinafusp alfa (targeting TfR) or angiopep-2 (targeting LRP1) are used to ferry therapeutic agents across the barrier (J-Stage). Therapeutic modulation of these components must be carefully managed to avoid off-target effects in peripheral tissues where these proteins are also expressed and to prevent permanent disruption of the barrier's protective function (Frontiers in Aging Neuroscience PMID: 33013346).

Other names

BBB endothelial cell surface proteinsBrain microvascular endothelial cell surface receptorsBBB-associated proteinsBlood-brain barrier

Drugs targeting these components typically act through receptor-mediated transcytosis (RMT), carrier-mediated transport (CMT), or the modulation of tight junction proteins to alter paracellular permeability. Some agents also inhibit efflux transporters to prevent the removal of drugs from the brain parenchyma.