TY  - JOUR
A1  - Bieber, Michael
A1  - Foerster, Kathrin I.
A1  - Haefeli, Walter E.
A1  - Pham, Mirko
A1  - Schuhmann, Michael K.
A1  - Kraft, Peter
T1  - Treatment with edoxaban attenuates acute stroke severity in mice by reducing blood–brain barrier damage and inflammation
JF  - International Journal of Molecular Sciences
N2  - Patients with atrial fibrillation and previous ischemic stroke (IS) are at increased risk of cerebrovascular events despite anticoagulation. In these patients, treatment with non-vitamin K oral anticoagulants (NOAC) such as edoxaban reduced the probability and severity of further IS without increasing the risk of major bleeding. However, the detailed protective mechanism of edoxaban has not yet been investigated in a model of ischemia/reperfusion injury. Therefore, in the current study we aimed to assess in a clinically relevant setting whether treatment with edoxaban attenuates stroke severity, and whether edoxaban has an impact on the local cerebral inflammatory response and blood–brain barrier (BBB) function after experimental IS in mice. Focal cerebral ischemia was induced by transient middle cerebral artery occlusion in male mice receiving edoxaban, phenprocoumon or vehicle. Infarct volumes, functional outcome and the occurrence of intracerebral hemorrhage were assessed. BBB damage and the extent of local inflammatory response were determined. Treatment with edoxaban significantly reduced infarct volumes and improved neurological outcome and BBB function on day 1 and attenuated brain tissue inflammation. In summary, our study provides evidence that edoxaban might exert its protective effect in human IS by modulating different key steps of IS pathophysiology, but further studies are warranted.
KW  - edoxaban
KW  - thrombo-inflammation
KW  - blood–brain barrier
KW  - tMCAO
KW  - experimental stroke
KW  - hemorrhagic transformation
KW  - NOAC
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-284481
SN  - 1422-0067
VL  - 22
IS  - 18
ER  - 
TY  - JOUR
A1  - Schuhmann, Michael K.
A1  - Bieber, Michael
A1  - Franke, Maximilian
A1  - Kollikowski, Alexander M.
A1  - Stegner, David
A1  - Heinze, Katrin G.
A1  - Nieswandt, Bernhard
A1  - Pham, Mirko
A1  - Stoll, Guido
T1  - Platelets and lymphocytes drive progressive penumbral tissue loss during middle cerebral artery occlusion in mice
JF  - Journal of Neuroinflammation
N2  - Background

In acute ischemic stroke, cessation of blood flow causes immediate tissue necrosis within the center of the ischemic brain region accompanied by functional failure in the surrounding brain tissue designated the penumbra. The penumbra can be salvaged by timely thrombolysis/thrombectomy, the only available acute stroke treatment to date, but is progressively destroyed by the expansion of infarction. The underlying mechanisms of progressive infarction are not fully understood.

Methods

To address mechanisms, mice underwent filament occlusion of the middle cerebral artery (MCAO) for up to 4 h. Infarct development was compared between mice treated with antigen-binding fragments (Fab) against the platelet surface molecules GPIb (p0p/B Fab) or rat immunoglobulin G (IgG) Fab as control treatment. Moreover, Rag1\(^{−/−}\) mice lacking T-cells underwent the same procedures. Infarct volumes as well as the local inflammatory response were determined during vessel occlusion.

Results

We show that blocking of the platelet adhesion receptor, glycoprotein (GP) Ibα in mice, delays cerebral infarct progression already during occlusion and thus before recanalization/reperfusion. This therapeutic effect was accompanied by decreased T-cell infiltration, particularly at the infarct border zone, which during occlusion is supplied by collateral blood flow. Accordingly, mice lacking T-cells were likewise protected from infarct progression under occlusion.

Conclusions

Progressive brain infarction can be delayed by blocking detrimental lymphocyte/platelet responses already during occlusion paving the way for ultra-early treatment strategies in hyper-acute stroke before recanalization.
KW  - ischemic penumbra
KW  - glycoprotein receptor Ib
KW  - T-cells
KW  - ischemic stroke
KW  - thrombo-inflammation
KW  - middle cerebral artery occlusion
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-259172
VL  - 18
IS  - 1
ER  -