Claudin-5 Controls Intercellular Barriers of Human Dermal Microvascular but Not Human Umbilical Vein Endothelial Cells

Abstract

Objective To assess the role claudin-5, an endothelial cell (EC) tight junction (TJ) protein, plays in establishing basal permeability levels in humans by comparing claudin-5 expression levels in situ and analyzing junctional organization and function in two widely used models of cultured ECs, namely human dermal microvascular (HDM)ECs and human umbilical vein (HUV)ECs. Methods and Results By immunofluorescence microscopy, ECs more highly express claudin-5 (but equivalently express VE-cadherin) in human dermal capillaries versus post-capillary venules and in umbilical and coronary arteries versus veins, correlating with known segmental differences in TJ frequencies and permeability barriers. Post-confluent cultured HDMECs express more claudin-5 (but equivalent VE-cadherin) and show higher transendothelial electrical resistance (TEER) and lower macromolecular flux than similarly cultured HUVECs. HDMEC junctions are more complex by transmission electron microscopy and show more continuous claudin-5 immunofluorescence than HUVEC junctions. Calcium chelation or dominant negative VE-cadherin overexpression decreases TEER and disrupts junctions in HUVECs, but not in HDMECs. Claudin-5 overexpression in HUVECs fails to increase TEER or claudin-5 continuity while claudin-5 knockdown in HDMECs, but not HUVECs, reduces TEER and increases antibody accessibility to junctional proteins. Conclusions Claudin-5 expression and junctional organization control HDMEC and arteriolar-capillary paracellular barriers whereas HUVEC and venular junctions utilize VE-cadherin.

Protein Kinase D Promotes Airway Epithelial Barrier Dysfunction and Permeability through Down-regulation of Claudin-1

“…The proposed mechanisms for PKD-mediated permeability in human umbilical vein endothelial cell monolayers are different from ours in airway epithelial cells. A recent study has demonstrated that claudin-5 and tight junctions control paracellular permeability in arteriolar and capillary endothelial cell monolayers, whereas human umbilical vein endothelial cell and venular junctions use adherent junctional protein VE-cadherin for regulating barrier function (57). Moreover, in retinal microvascular endothelial cells, VEGF disturbs the barrier of the endothelial cell monolayers by inducing down-regulation of claudin-1 but not claudin-3, claudin-5, ZO-1, and VE-cadherin (58).…”

Efficacy and Biological Activity of Imatinib in Metastatic Dermatofibrosarcoma Protuberans (DFSP)

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The actin-binding protein EPS8 binds VE-cadherin and modulates YAP localization and signaling

“…ECs from different types of vessels and also from different organs show differences in junction composition and organization Kluger et al, 2013).…”