Platelets play a key role in strokes: They can even drive nerve cells in the brain into a kind of suicide mode, as scientists from the University of Würzburg now report in the journal "Blood".
A stroke typically develops as follows: A blood vessel supplying the brain with vital oxygen and nutrients is blocked by a blood clot, resulting in nerve cell death. Signs and symptoms of a stroke can include inability to move and speech problems.
Platelets are a major constituent of these blood clots. They are small cell fragments that circulate in the blood vessels whose function is to stop bleeding and close wounds.
"Scientists have suspected platelets to play an important role in the development of strokes for quite some time. But their exact function was unknown until recently," says Professor Christoph Kleinschnitz, head of the Stroke Unit of the Department of Neurology of the Würzburg University Hospital.
Detrimental platelet factor
Together with colleagues from Tübingen and Belgium, the Würzburg researchers have now closed this knowledge gap. What's special about their discovery: They found out that platelets are harmful in different phases of the stroke.
In the early phase, the platelets release a special clotting protein called the Von Willebrand factor. As the scientists report in the renowned journal "Blood", this factor promotes clotting in the brain and aggravates the brain damage after a stroke.
Platelets can trigger apoptosis
But platelets are equally significant in the later phase of a stroke. In a further article in "Blood", the research team demonstrates that the platelets subsequently travel from the vessels into the brain tissue where they can directly damage the nerve cells.
"The underlying mechanism is called apoptosis," explains Dr Peter Kraft from the Department of Neurology of the Würzburg University Hospital. This is a kind of suicide programme of the nerve cells. It is activated once the platelets come into contact with the nerve cells. The researchers have proved that platelets are capable of triggering apoptosis in the brain for the first time ever.
Promising antibodies for therapy
"In order to develop new targets for therapy, it is crucial to understand how platelets behave in the various stages of the stroke," Professor Kleinschnitz explains. "We are pinning our hopes on novel antibodies that are capable of suppressing the harmful function of the platelets." In animal models, these antibodies still work even when they are administered as late as one hour after the stroke.
Moreover, the antibodies can mitigate the nerve-damaging effect of the Von Willebrand factor. And they cause the nerve cells to go into suicide mode less frequently. "So antibodies could target different causes of stroke and be beneficial to many patients," Kleinschnitz says. Before translating into actual therapies, however, additional investigations and safety tests will have to be conducted.
Their research was funded by Deutsche Forschungsgemeinschaft (DFG) within the scope of the Würzburg Collaborative Research Center 688.
Two publications in "Blood"
“Platelets induce apoptosis via membrane-bound FasL”, Rebecca I. Schleicher, Frank Reichenbach, Peter Kraft, Anil Kumar, Mario Lescan, Franziska Todt, Kerstin Göbel, Tobias Geisler, Axel Bauer, Marcus Olbrich, Martin Schaller, Sebastian Wesselborg, Lorraine O’Reilly, Sven G. Meuth, Klaus Schulze-Osthoff, Meinrad Gawaz, Xuri Li, Christoph Kleinschnitz, Frank Edlich, and Harald F. Langer, Blood, 31 July 2015, DOI: http://dx.doi.org/10.1182/blood-2013-12-544445
“While not essential for normal thrombosis and hemostasis, platelet-derived von Willebrand factor fosters cerebral ischemia reperfusion injury in mice”, Sebastien Verhenne, Frederik Denorme, Sarah Libbrecht, Aline Vandenbulcke, Inge Pareyn, Hans Deckmyn, Antoon Lambrecht, Bernhard Nieswandt, Christoph Kleinschnitz, Karen Vanhoorelbeke, Simon F. De Meyer, Blood, 24 July 2015, DOI: http://dx.doi.org/10.1182/blood-2015-03-632901
Prof. Dr. Christoph Kleinschnitz, Department of Neurology of the Würzburg University Hospital, Phone: +49 931 201-23756, firstname.lastname@example.org
Robert Emmerich | idw - Informationsdienst Wissenschaft
Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY
NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences