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F. Denorme et al.
anti-VWF A1 nanobody KB-VWF-006bv had significantly less ischemic stroke brain damage than had control-treat- ed mice (Figure 4A and B). This translated into an improved motor score (Figure 4C) and neurological behavior (Figure 4D), although the difference was only statistically significant for the latter. Of note, no intracra- nial bleeding was observed in any of the mice treated
AB
with the VWF A1 nanobody. These data further corrobo- rate the crucial involvement of the VWF-GPIba axis in cerebral ischemia/reperfusion injury.15-17,19
Targeting the VWF A1 domain also significantly reduced inflammatory cell recruitment to the ischemic brain (Figure 5). Indeed, similar to our results in VWF KO mice, flow cytometric analysis revealed that inhibition of
CD
EF
GH
high
nocytes (CD45 ; CD11b+;
Figure 1. von Willebrand fac- tor deficiency leads to a reduc- tion of the number of mono- cytes, neutrophils and T cells to the brain after acute ischemic stroke. (A-H) Transient focal cerebral ischemia was induced by occlusion of the right middle cerebral artery for 60 min in
wild-type (WT)
Willebrand factor (VWF) knock- out (KO) mice. This was fol- lowed by 23 h of reperfusion, after which edema-corrected brain infarct volumes were quantified by planimetric analysis (A) and white blood cell recruitment to each hemi- sphere was determined by flow cytometry (B-H). The total number of white blood cells (CD45high) was analyzed (B) as well as the myeloid (CD45high; CD11b+) (C) and lymphoid white blood cells (CD45high; CD11b-; CD11c-) (D). More specifically, neutrophils (CD45high; CD11b+; Ly6G+) (E), T cells (CD45high; CD11b-; CD11c-; CD3e+) (F); inflammatory mo-
Ly6C+; Ly6G-) (G) and CD3neg lymphocytes (CD45high; CD11b-; CD11c-; CD3e-) (H) were quan- tified. Data are represented as box plots showing all data points and the median value, except for infarct size which is shown as mean ± standard deviation. *P<0.05; **P<0.01; ***P<0.005; ****P<0.001; ns: not statisti- cally significant. (n=8-9). WBC: white blood cells; Ipsi: ipsilat- eral cerebral hemisphere; con- tra: contralateral cerebral hemisphere.
and von
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haematologica | 2021; 106(3)