Pro- and antifibrinolytic properties of human pulmonary microvascular versus artery endothelial cells: impact of endotoxin and tumor necrosis factor-alpha.
OBJECTIVE
Microvascular thrombosis is a common feature of acute inflammatory lung injury, as occurs in sepsis and acute respiratory distress syndrome, but the underlying pathomechanisms are presently not fully understood.


METHODS
Experimental.


METHODS
University laboratory.


METHODS
Lung endothelial cells.


METHODS
We characterized the expression of tissue-type and urokinase-type plasminogen activator (t-PA and u-PA) as well as plasminogen activator inhibitor (PAI)-1 and PAI-2 in human endothelial cells (EC) from the microvascular pulmonary circulation (HMVEC-L) and compared it with that of EC from pulmonary artery (HPAEC) and umbilical vein (HUVEC) under baseline conditions and upon stimulation with either tumor necrosis factor-alpha or lipopolysaccharide.


RESULTS
Real-time reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay were employed for quantification of messenger RNA and protein concentrations. Under baseline conditions, comparable PAI-1 expression was noted in all EC. HPAEC were characterized by significantly higher baseline expression of t-PA and PAI-2 compared with HUVEC and HMVEC-L. In contrast, u-PA messenger RNA concentrations were found to be significantly higher in nonstimulated HMVEC-L compared with HUVEC and HPAEC. In all EC, stimulation with tumor necrosis factor-alpha and lipopolysaccharide increased the expression of PAI-1, PAI-2, and u-PA and decreased t-PA expression. The changes in messenger RNA content were reflected by corresponding changes in the protein concentrations.


CONCLUSIONS
High baseline u-PA expression is a prominent feature of human lung microvascular EC, whereas pulmonary artery EC are characterized by high t-PA concentrations. Microbial and inflammatory challenge provokes up-regulation of PAI-1 and PAI-2 and down-regulation of t-PA in both macro- and microvascular pulmonary EC, which may favor local fibrin deposition.
Muth
H
H
Department of Internal Medicine, Justus-Liebig-University Giessen, Germany.
Maus
U
U
Wygrecka
M
M
Lohmeyer
J
J
Grimminger
F
F
Seeger
W
W
Günther
A
A
D001483:Base Sequence; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000166:cytology* / Q000187:drug effects; D006801:Humans; D007150:Immunohistochemistry; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008969:Molecular Sequence Data; D015999:Multivariate Analysis; D017395:Plasminogen Activator Inhibitor 1 / Q000032:analysis / Q000378:metabolism*; D011336:Probability; D011651:Pulmonary Artery / Q000166:cytology; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D012680:Sensitivity and Specificity; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D014471:Umbilical Veins / Q000166:cytology; D014568:Urokinase-Type Plasminogen Activator / Q000187:drug effects / Q000378:metabolism*
D008070:Lipopolysaccharides; D017395:Plasminogen Activator Inhibitor 1; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D014568:Urokinase-Type Plasminogen Activator