The tumour necrosis factor-alpha induced vascular permeability is associated with a reduction of VE-cadherin expression.
BACKGROUND
Vascular permeability is controlled by endothelial cell-to-cell junctions. Vascular endothelial (VE)-cadherin, the major component of adherence junctions (AJ) in the endothelium, is the target of the permeability-increasing agent tumour necrosis factor-a (TNF-alpha). We investigated whether TNF-alpha regulates the synthesis of VE-cadherin on the transcriptional level.


METHODS
Human endothelial cells, isolated from aorta (aEC) and umbilical cord (HUVEC), were exposed to TNF-alpha (200 U/ml) for 6 h or 12 h, with and without subsequent incubation with TNF-alpha for 24 h. VE-cadherin mRNA was evaluated by semi-quantitative RT-PCR. The VE-Cadherin protein expression was analyzed by flow cytometry (FACS).


RESULTS
The VE-cadherin amplification curve of TNF-alpha treated cells was shifted to the right compared to controls, indicating a lower mRNA amount. The number of cycles at which half-maximal amplification (N50) was achieved, was lower for control aEC (30.7) than for TNF-alpha treated aEC (33.0). The N50 of HUVEC treated with TNF-alpha for 12 h and 12 h + 24 h medium (N50 = 32.1), was higher compared to controls (N50 = 29.7) and cells treated with TNF-alpha for 6 h (N50 = 30.8). As determined by FACS analysis, incubation with TNF-alpha caused a small decrease of VE-cadherin protein expression from 7.44 to 6.05 mean channel intensity.


CONCLUSIONS
Our results indicate that TNF-alpha affects VE-cadherin gene expression on the transcriptional level, inducing a downregulation of the VE-cadherin expression.
Hofmann
S
S
Division of Experimental Diabetes and Aging, Department of Geriatrics and Adult Development, The Mount Sinai Medical Center, New York, New York 10029-6674, USA. susanna.hofmann@mssm.edu
Grasberger
H
H
Jung
P
P
Bidlingmaier
M
M
Vlotides
J
J
Janssen
O E
OE
Landgraf
R
R
D015703:Antigens, CD; D001483:Base Sequence; D015820:Cadherins / Q000235:genetics*; D002199:Capillary Permeability / Q000187:drug effects*; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D019040:E-Selectin / Q000235:genetics; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism; D005434:Flow Cytometry; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D000099152:Cadherin 5
D015703:Antigens, CD; D015820:Cadherins; D019040:E-Selectin; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D000099152:Cadherin 5