Figure 9.

Detection and characterization of plasma MPs in an experimental model of ischemic stroke in mice. (A) Schematic representation of the experimental stroke model induced by intra-arterial injection of thrombin. (B) Timeline of the experiments. MPs were purified from plasma samples obtained 30 minutes after the end of saline or tPA infusion. (C) Representative T2-weighted (T2W), Diffusion-weighted (DWI) and magnetic resonance angiography (MRA) images obtained in control mice and 1 hour after ischemic onset in a saline treated mouse. The yellow arrowhead represents the ischemic core, only visible on DWI and not in T2W images, which is a characteristic of an acute ischemic lesion. On the MRA, the left middle cerebral artery is circled in green and the right in red. In the stroke mouse, we cannot see anymore the right middle cerebal artery which is occluded by a thrombin-triggered thrombus. (D) Representative LSCM images of MPs (CFSE, green) from control, stroke and stroke+tPA mice. (E) Quantification of plasmatic MPs number from from control, stroke and stroke+tPA mice (n=5 per group). (F) Quantification of the apparent MPs diameter in the three groups, showing the lack of significant differences (n=5 per group). (G) Representative images of anti-tPA immunolabelled MPs from a tPA-treated stroke mouse showing numerous tPA positive (arrowhead) and tPA negative (arrow) MPs in this mouse. (H) Corresponding quantification (n=5 per group). Data are means ± SD. Statistical analyses were performed Kruskal-Wallis (for multiple comparisons) followed by Mann-Whitney's U-test.