TY  - JOUR
A1  - Kraft, Peter
A1  - De Meyer, Simon F.
A1  - Kleinschnitz, Christoph
T1  - Next-Generation Antithrombotics in Ischemic Stroke: Preclinical Perspective on ‘Bleeding-Free Antithrombosis’
JF  - Journal of Cerebral Blood Flow and Metabolism
N2  - The present antithrombotic drugs used to treat or prevent ischemic stroke have significant limitations: either they show only moderate efficacy (platelet inhibitors), or they significantly increase the risk for hemorrhages (thrombolytics, anticoagulants). Although most strokes are caused by thrombotic or embolic vessel occlusions, the pathophysiological role of platelets and coagulation is largely unclear. The introduction of novel transgenic mouse models and specific coagulation inhibitors facilitated a detailed analysis of molecular pathways mediating thrombus formation in models of acute ischemic stroke. Prevention of early platelet adhesion to the damaged vessel wall by blocking platelet surface receptors glycoprotein Ib alpha (GPIbα) or glycoprotein VI (GPVI) protects from stroke without provoking bleeding complications. In addition, downstream signaling of GPIbα and GPVI has a key role in platelet calcium homeostasis and activation. Finally, the intrinsic coagulation cascade, activated by coagulation factor XII (FXII), has only recently been identified as another important mediator of thrombosis in cerebrovascular disease, thereby disproving established concepts. This review summarizes the latest insights into the pathophysiology of thrombus formation in the ischemic brain. Potential clinical merits of novel platelet inhibitors and anticoagulants as powerful and safe tools to combat ischemic stroke are discussed.
KW  - von Willebrand factor
KW  - platelets
KW  - glycoprotein Ib
KW  - FXII
KW  - coagulation
KW  - Stim
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-126538
VL  - 32
IS  - 10
ER  - 
TY  - JOUR
A1  - Dütting, Sebastian
A1  - Gaits-Iacovoni, Frederique
A1  - Stegner, David
A1  - Popp, Michael
A1  - Antkowiak, Adrien
A1  - van Eeuwijk, Judith M.M.
A1  - Nurden, Paquita
A1  - Stritt, Simon
A1  - Heib, Tobias
A1  - Aurbach, Katja
A1  - Angay, Oguzhan
A1  - Cherpokova, Deya
A1  - Heinz, Niels
A1  - Baig, Ayesha A.
A1  - Gorelashvili, Maximilian G.
A1  - Gerner, Frank
A1  - Heinze, Katrin G.
A1  - Ware, Jerry
A1  - Krohne, Georg
A1  - Ruggeri, Zaverio M.
A1  - Nurden, Alan T.
A1  - Schulze, Harald
A1  - Modlich, Ute
A1  - Pleines, Irina
A1  - Brakebusch, Cord
A1  - Nieswandt, Bernhard
T1  - A Cdc42/RhoA regulatory circuit downstream of glycoprotein Ib guides transendothelial platelet biogenesis
JF  - Nature Communications
N2  - Blood platelets are produced by large bone marrow (BM) precursor cells, megakaryocytes (MKs), which extend cytoplasmic protrusions (proplatelets) into BM sinusoids. The molecular cues that control MK polarization towards sinusoids and limit transendothelial crossing to proplatelets remain unknown. Here, we show that the small GTPases Cdc42 and RhoA act as a regulatory circuit downstream of the MK-specific mechanoreceptor GPIb to coordinate polarized transendothelial platelet biogenesis. Functional deficiency of either GPIb or Cdc42 impairs transendothelial proplatelet formation. In the absence of RhoA, increased Cdc42 activity and MK hyperpolarization triggers GPIb-dependent transmigration of entire MKs into BM sinusoids. These findings position Cdc42 (go-signal) and RhoA (stop-signal) at the centre of a molecular checkpoint downstream of GPIb that controls transendothelial platelet biogenesis. Our results may open new avenues for the treatment of platelet production disorders and help to explain the thrombocytopenia in patients with Bernard–Soulier syndrome, a bleeding disorder caused by defects in GPIb-IX-V.
KW  - megakaryocytes
KW  - blood platelets
KW  - regulatory circuit downstream
KW  - glycoprotein Ib
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170797
VL  - 8
IS  - 15838
ER  -