Upregulation of transmembrane endothelial junction proteins in human cerebral cavernous malformations.
OBJECTIVE
Cerebral cavernous malformations (CCMs) are among the most prevalent cerebrovascular malformations, and endothelial cells seem to play a major role in the disease. However, the underlying mechanisms, including endothelial intercellular communication, have not yet been fully elucidated. In this article, the authors focus on the endothelial junction proteins CD31, VE-cadherin, and occludin as important factors for functional cell-cell contacts known as vascular adhesion molecules and adherence and tight junctions.


METHODS
Thirteen human CCM specimens and 6 control tissue specimens were cryopreserved and examined for the presence of VE-cadherin, occludin, and CD31 by immunofluorescence staining. Protein quantification was performed by triplicate measurements using western blot analysis.


RESULTS
Immunofluorescent analyses of the CCM sections revealed a discontinuous pattern of dilated microvessels and capillaries as well as increased expression of occludin, VE-cadherin, and CD31 in the intima and in the enclosed parenchymal tissue compared with controls. Protein quantification confirmed these findings by showing upregulation of the levels of these proteins up to 2-6 times.


CONCLUSIONS
A protocol enabling the molecular and morphological examination of the intercellular contact proteins in human CCM was validated. The abnormal and discontinuous pattern in these endothelial cell-contact proteins compared with control tissue explains the loose intercellular junctions that are considered to be one of the causes of CCM-associated bleeding or transendothelial oozing of erythrocytes. Despite the small number of specimens, this study demonstrates for the first time a quantitative analysis of endothelial junction proteins in human CCM.
Burkhardt
Jan-Karl
JK
Department of Neurosurgery, University Hospital Zurich, Zurich, Switzerland. JanKarl.Burkhardt@gmail.com
Schmidt
Dörthe
D
Schoenauer
Roman
R
Brokopp
Chad
C
Agarkova
Irina
I
Bozinov
Oliver
O
Bertalanffy
Helmut
H
Hoerstrup
Simon P
SP
D000293:Adolescent; D000328:Adult; D015703:Antigens, CD / Q000378:metabolism*; D015153:Blotting, Western; D015820:Cadherins / Q000378:metabolism*; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism; D002450:Cell Communication / Q000235:genetics / Q000502:physiology; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000378:metabolism; D004727:Endothelium; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D005260:Female; D020786:Hemangioma, Cavernous, Central Nervous System / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007365:Intercellular Junctions / Q000235:genetics / Q000378:metabolism*; D002538:Intracranial Arteriovenous Malformations / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008875:Middle Aged; D052250:Nitric Oxide Synthase Type III; D062793:Occludin; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism; D019108:Tight Junctions / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation / Q000235:genetics / Q000502:physiology; D000099152:Cadherin 5
D015703:Antigens, CD; D015820:Cadherins; D015815:Cell Adhesion Molecules; D008565:Membrane Proteins; D052250:Nitric Oxide Synthase Type III; D062793:Occludin; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D000099152:Cadherin 5; C568985:OCLN protein, human; C496314:NOS3 protein, human