[Effects of reduced shear stress on inflammatory reactions in vitro. Effects of pathological flow conditions on leukocyte-endothelial interactions and monocyte tissue factor expression in human cell cultures].
BACKGROUND
During malperfusion and inflammation leukocyte adhesion is common. The purpose of this study was to examine the effects of reduced shear stress on leukocyte-endothelial interactions and subsequent inflammatory reactions such as up-regulation of tissue factor.


METHODS
Isolated neutrophils and monocytes were co-incubated with human umbilical venous endothelium at 0-3 dynes/cm(2) in a flow chamber. Adhesion and tissue factor expression on adherent leukocytes were examined at various flow conditions.


RESULTS
At 2-3 dynes/cm(2) adhesion occurred only on TNFalpha-activated endothelium. Below 1 dyne/cm(2) similarly increased adhesion was also observed on non-activated endothelium. As was observed for leukocyte adhesion, these shear stress-dependent cell interactions also resulted in an up-regulation of tissue factor on adherent monocytes from non-activated co-cultures.


CONCLUSIONS
Apart from additional activators of inflammation, reduced shear forces may directly contribute to inflammation.
Nohé
B
B
Abteilung für Anaesthesiologie und Intensivmedizin, Universitätsklinikum, Tübingen. boris.nohe@uni-tuebingen.de
Johannes
T
T
Schmidt
V
V
Schroeder
T H
TH
Kiefer
R T
RT
Unertl
K
K
Dieterich
H J
HJ
D002448:Cell Adhesion; D015815:Cell Adhesion Molecules / Q000378:metabolism; D002478:Cells, Cultured; D018920:Coculture Techniques; D042783:Endothelial Cells / Q000473:pathology*; D005434:Flow Cytometry; D006801:Humans; D007249:Inflammation / Q000378:metabolism* / Q000473:pathology*; D007962:Leukocytes / Q000473:pathology*; D009000:Monocytes / Q000378:metabolism*; D013314:Stress, Mechanical; D013925:Thromboplastin / Q000096:biosynthesis*; D014409:Tumor Necrosis Factor-alpha / Q000502:physiology; D015854:Up-Regulation / Q000502:physiology
D015815:Cell Adhesion Molecules; D014409:Tumor Necrosis Factor-alpha; D013925:Thromboplastin