Regensburg 2016 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 43: Cell Adhesion
BP 43.3: Vortrag
Mittwoch, 9. März 2016, 15:45–16:00, H43
Cytoskeletal dynamics in blood platelets during spreading on fibrinogen — •Ingmar Schön, Sebastian Lickert, and Viola Vogel — Laboratory of Applied Mechanobiology, ETH Zurich, Switzerland
Blood platelets are small anucleate cells that form a thrombus during blood coagulation. The most abundant platelet integrin αIIb β3 specifically binds fibrinogen and thereby enables platelet aggregation. Patients with Glanzmann Thrombasthenia (GT) carry a genetic mutation in integrin αIIb β3 and suffer from defective platelet aggregation and excessive bleeding. Here we investigated the spreading of healthy or GT platelets on fibrinogen-coated surfaces by time-lapse fluorescence imaging, confocal microscopy, and super-resolution microscopy (dSTORM). Healthy platelets re-arranged their cytoskeleton and adhesion complexes during spreading from an early "stellar" arrangement into pronounced bundles spanning the whole cell. GT platelets also adhered and spread on fibrinogen but exclusively exhibited a stellar cytoskeletal arrangement. Based on these findings we hypothesize that cytoskeletal dynamics of GT platelets gets stalled at an early stage of the spreading process. We will present results from experiments with specific inhibitors, knock-out cells, different ligand proteins, and other means that aimed at identifying the crucial step where things went awry.
In general, we suggest that platelets are an interesting biophysical model system to study the autonomous, acto-myosin-driven cytoskeletal dynamics during adhesion formation.