Molecular Classification
Other (cellular structure), Tight junction protein complex
Other Names
Blood-brain barrier tight junction, BBB tight junction, Endothelial tight junction of the blood-brain barrier
Disease Roles
Neurodegenerative diseaseInflammationOther CNS disorders involving blood-brain barrier dysfunction

Blood-brain barrier endothelial tight junction Overview

The blood-brain barrier endothelial tight junction is a specialized intercellular structure formed by protein complexes between adjacent endothelial cells lining the cerebral microvasculature. These tight junctions are primarily composed of transmembrane proteins such as claudin‑5, occludin, and JAM-A, which are anchored by cytoplasmic scaffolding proteins like ZO1. The main function is to create a highly selective physical and biochemical barrier that restricts paracellular diffusion of solutes from the bloodstream into the brain parenchyma[3][4][6]. This selectivity maintains CNS homeostasis but also presents a major obstacle for therapeutic drug delivery to neural tissue. Disruption or dysfunction of these complexes is implicated in various neurological diseases due to increased permeability and loss of protective function[1][2][4]. Note: This entry refers not to a single molecular target but rather a structural complex made up of multiple proteins (e.g., claudin‑5, occludin). It is not considered an individual therapeutic target like an enzyme or receptor; instead, its constituent proteins may be targeted individually for research or therapy. Therefore, "Blood-brain barrier endothelium tight junctions" as written does not correspond precisely with standard molecular target nomenclature and should be mapped instead to specific components such as "Claudin‑5" or "Occludin"[1][3].

Mechanism of Action

Biological Functions

Physical barrier formation
Regulation of paracellular permeability
Maintenance of central nervous system (CNS) homeostasis

Disease Associations

Neurodegenerative disease
Inflammation
Other CNS disorders involving blood-brain barrier dysfunction

Safety Considerations

  • Barrier to drug delivery to the brain

Associated Biomarkers

Biomarker
Claudin-5 expression levels
Occludin expression levels