Blood-brain barrier paracellular junctional complex (BBB-PJC) (BBB-PJC)

The brain endothelial paracellular barrier is a highly specialized structural component of the blood-brain barrier (BBB) that regulates the movement of ions and molecules between endothelial cells [1]. It is primarily composed of tight junctions (TJs) and adherens junctions (AJs), which create a high-resistance seal through the interaction of transmembrane proteins like claudin-5, occludin, and junctional adhesion molecules (JAMs) [2]. This barrier is critical for maintaining central nervous system (CNS) homeostasis by preventing the entry of neurotoxic substances and pathogens while allowing for the precise control of the brain's microenvironment [3]. Dysfunction of this barrier is a hallmark of several neurological conditions, including stroke, multiple sclerosis, and Alzheimer's disease, where increased permeability leads to neuroinflammation and tissue damage [4]. In drug development, the paracellular barrier represents both a challenge for drug delivery and a target for therapeutic stabilization or transient opening to allow the passage of large-molecule therapeutics [5].

Other names

Brain endothelial tight junctionParacellular pathway of the blood-brain barrierEndothelial paracellular barrierBBB paracellular barrier

Modulation of paracellular permeability through osmotic disruption of junctional integrity, pharmacological stabilization of tight junction proteins, or signaling-mediated reorganization of the actin cytoskeleton [1, 4, 5].