[Fluid shear stress regulates secretion of tissue-type plasminogen activator in human endothelial progenitor cells].
OBJECTIVE
In order to investigate the role of shear stress in the regulation of endothelial function, we assessed here effects of shear stress on tissue-type plasminogen activator in human endothelial progenitor cells (EPCs).


METHODS
The peripheral blood mononuclear cells were separated from healthy adult and inducted into EPCs, which were identified by double staining for the fluorescent labeled acetylated-LDL and lectin. EPCs were seeded on the small diameter artificial vessels, and then divided into four different experimental groups including stationary group, low-flow shear stress group (5 dyn/cm(2)), medium-flow shear stress group (15 dyn/cm(2)) and high-flow shear stress group (25 dyn/cm(2)). The levels of t-PA in EPC culture medium at 0 hour, 5 hours, 10 hours, 15 hours, 20 hours and 25 hours after culture were measured by enzyme-linked immunosorbent assay.


RESULTS
The peripheral blood mononuclear cells differentiated into EPCs after induction, which were positively labeled by fluorescent acetylated-LDL and lectin. Shear stress enhanced production of the t-PA by EPCs, which was paralleled to levels and times of shear stress.


CONCLUSIONS
Shear stress increases t-PA secretion by human EPCs, suggesting that shear stress not only regulates vascular endothelial function but also participates in the pathogenesis of arteriosclerosis.
Yang
Zhen
Z
Department of Cardiology, First Affiliated Hospital, SUN Yat-sen University, Guangzhou 510080, China.
Tao
Jun
J
Tu
Chang
C
Xu
Ming-guo
MG
Wang
Yan
Y
Wang
Jie-mei
JM
Pan
Shi-rong
SR
D000328:Adult; D042783:Endothelial Cells / Q000378:metabolism*; D006801:Humans; D013234:Stem Cells / Q000378:metabolism*; D013314:Stress, Mechanical; D010959:Tissue Plasminogen Activator / Q000378:metabolism*
D010959:Tissue Plasminogen Activator