Figure 2. CXCL4 increases endothelial permeability in a receptor independent manner and mediates endothelial intracellular signalling.

(A) Chemokine mediated chemotaxis of relevant receptor expressing cells; CXCL4, CCL2 or CCL5 (monocytes), CXCL12 (CXCR4⁺ Jurkat cells), CCL21 (CCR7⁺ L1.2 cells) and CXCL8 (CXCR2⁺ neutrophils). (B) Transendothelial migration of human monocytes towards CXCL4. (C) Transwell endothelial permeability in the absence and presence of CXCL4, (D) CXCL4 alone or in combination with pertussis toxin. (E) Schematic of cranial window implantation for in vivo vascular permeability analysis. (F) In vivo analysis of leakage of intravenously injected fluorescent dextran from the vasculature into the meninges following intravenous injection of CXCL4 or vehicle control. (G) Quantification of (F). (H) Heat map of the Log2 fold change of indicated protein phosphorylation sites from endothelial cells stimulated with CXCL4, relative to vehicle controls.

All plots are mean with 95% confidence intervals, represent at least two separate experiments where data have been pooled. Each dot in A-D represents an individual transwell and each dot in G represents an individual mouse. Data in A-D and G are normalised to vehicle controls. Individual p values are shown, and C analysed using an unpaired t-test, D and G using a one-way ANOVA with a post-hoc Tukey analysis.