کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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3027932 | 1182995 | 2010 | 7 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Flow-based measurements of von Willebrand factor (VWF) function: Binding to collagen and platelet adhesion under physiological shear rate Flow-based measurements of von Willebrand factor (VWF) function: Binding to collagen and platelet adhesion under physiological shear rate](/preview/png/3027932.png)
IntroductionVWF circulates in plasma as a series of heterogeneous multimers, mediating platelet tethering, translocation and finally adhesion to areas of injured endothelium under physiological high arterial blood flow. VWF-platelet binding requires conformational changes in VWF, which are induced by immobilization and shear. Because of unavailability of a simple flow-based measurement system, VWF activity assays are generally performed under static conditions. We describe an easily reproducible in vitro flow-chamber model using commercially available flow devices to examine VWF-collagen binding and VWF-mediated platelet adhesion under physiological flow conditions.MethodsThe collagen surface of the flow-chamber was analyzed by atomic force microscopy. Collagen-bound VWF was characterized by multimer analysis and multi labelling immunofluorescence detection of exposed GPIb binding domains. Platelet adhesion was captured by time-lapse microscopy.ResultsThe described flow-chamber system facilitates multimer analysis of collagen-bound VWF, whereas all VWF multimers bound to collagen under physiological low to high shear rates. Multi labelling immunofluorescence detection exhibited exposed GPIb binding domains co-localized with VWF molecules. VWF-dependent platelet adhesion using time-lapse microscopy showed values comparable to experiments done with whole blood, and platelet adhesion was dependent on the VWF concentration.ConclusionsThe established flow-chamber model represents an easy-to-set-up and customized tool for the characterization of VWF-binding to collagen as well as the determination of VWF-dependent platelet adhesion under defined flow conditions in real-time.
Journal: Thrombosis Research - Volume 125, Issue 3, March 2010, Pages 239–245