TY  - JOUR
A1  - Han, Chao
A1  - Ren, Pengxuan
A1  - Mamtimin, Medina
A1  - Kruk, Linus
A1  - Sarukhanyan, Edita
A1  - Li, Chenyu
A1  - Anders, Hans-Joachim
A1  - Dandekar, Thomas
A1  - Krueger, Irena
A1  - Elvers, Margitta
A1  - Goebel, Silvia
A1  - Adler, Kristin
A1  - Münch, Götz
A1  - Gudermann, Thomas
A1  - Braun, Attila
A1  - Mammadova-Bach, Elmina
T1  - Minimal collagen-binding epitope of glycoprotein VI in human and mouse platelets
JF  - Biomedicines
N2  - Glycoprotein VI (GPVI) is a platelet-specific receptor for collagen and fibrin, regulating important platelet functions such as platelet adhesion and thrombus growth. Although the blockade of GPVI function is widely recognized as a potent anti-thrombotic approach, there are limited studies focused on site-specific targeting of GPVI. Using computational modeling and bioinformatics, we analyzed collagen- and CRP-binding surfaces of GPVI monomers and dimers, and compared the interacting surfaces with other mammalian GPVI isoforms. We could predict a minimal collagen-binding epitope of GPVI dimer and designed an EA-20 antibody that recognizes a linear epitope of this surface. Using platelets and whole blood samples donated from wild-type and humanized GPVI transgenic mice and also humans, our experimental results show that the EA-20 antibody inhibits platelet adhesion and aggregation in response to collagen and CRP, but not to fibrin. The EA-20 antibody also prevents thrombus formation in whole blood, on the collagen-coated surface, in arterial flow conditions. We also show that EA-20 does not influence GPVI clustering or receptor shedding. Therefore, we propose that blockade of this minimal collagen-binding epitope of GPVI with the EA-20 antibody could represent a new anti-thrombotic approach by inhibiting specific interactions between GPVI and the collagen matrix.
KW  - GPVI
KW  - collagen
KW  - blood platelets
KW  - thrombosis
KW  - anti-thrombotic therapies
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-304148
SN  - 2227-9059
VL  - 11
IS  - 2
ER  - 
TY  - JOUR
A1  - Nagy, Magdolna
A1  - van Geffen, Johanna P.
A1  - Stegner, David
A1  - Adams, David J.
A1  - Braun, Attila
A1  - de Witt, Susanne M.
A1  - Elvers, Margitta
A1  - Geer, Mitchell J.
A1  - Kuijpers, Marijke J. E.
A1  - Kunzelmann, Karl
A1  - Mori, Jun
A1  - Oury, Cécile
A1  - Pircher, Joachim
A1  - Pleines, Irina
A1  - Poole, Alastair W.
A1  - Senis, Yotis A.
A1  - Verdoold, Remco
A1  - Weber, Christian
A1  - Nieswandt, Bernhard
A1  - Heemskerk, Johan W. M.
A1  - Baaten, Constance C. F. M. J.
T1  - Comparative Analysis of Microfluidics Thrombus Formation in Multiple Genetically Modified Mice: Link to Thrombosis and Hemostasis
JF  - Frontiers in Cardiovascular Medicine
N2  - Genetically modified mice are indispensable for establishing the roles of platelets in arterial thrombosis and hemostasis. Microfluidics assays using anticoagulated whole blood are commonly used as integrative proxy tests for platelet function in mice. In the present study, we quantified the changes in collagen-dependent thrombus formation for 38 different strains of (genetically) modified mice, all measured with the same microfluidics chamber. The mice included were deficient in platelet receptors, protein kinases or phosphatases, small GTPases or other signaling or scaffold proteins. By standardized re-analysis of high-resolution microscopic images, detailed information was obtained on altered platelet adhesion, aggregation and/or activation. For a subset of 11 mouse strains, these platelet functions were further evaluated in rhodocytin- and laminin-dependent thrombus formation, thus allowing a comparison of glycoprotein VI (GPVI), C-type lectin-like receptor 2 (CLEC2) and integrin α6β1 pathways. High homogeneity was found between wild-type mice datasets concerning adhesion and aggregation parameters. Quantitative comparison for the 38 modified mouse strains resulted in a matrix visualizing the impact of the respective (genetic) deficiency on thrombus formation with detailed insight into the type and extent of altered thrombus signatures. Network analysis revealed strong clusters of genes involved in GPVI signaling and Ca2+ homeostasis. The majority of mice demonstrating an antithrombotic phenotype in vivo displayed with a larger or smaller reduction in multi-parameter analysis of collagen-dependent thrombus formation in vitro. Remarkably, in only approximately half of the mouse strains that displayed reduced arterial thrombosis in vivo, this was accompanied by impaired hemostasis. This was also reflected by comparing in vitro thrombus formation (by microfluidics) with alterations in in vivo bleeding time. In conclusion, the presently developed multi-parameter analysis of thrombus formation using microfluidics can be used to: (i) determine the severity of platelet abnormalities; (ii) distinguish between altered platelet adhesion, aggregation and activation; and (iii) elucidate both collagen and non-collagen dependent alterations of thrombus formation. This approach may thereby aid in the better understanding and better assessment of genetic variation that affect in vivo arterial thrombosis and hemostasis.
KW  - arterial thrombus formation
KW  - bleeding
KW  - collagen
KW  - glycoprotein VI
KW  - platelets
KW  - microfluidics
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-232194
VL  - 6
ER  -