PDPN deletion in reactive astrocytes does not affect intratumoral platelet aggregates. (A) Immunofluorescence staining of astrocytes isolated from mice with the indicated genotype. PDPN (green), GFAP (red), DAPI (blue). Scale bars, 20 µm. (B) In vitro platelet aggregation (percentage) of platelets incubated with tumor cells isolated from DKO-NSC and TKO^{Pdpn neg}-NSC orthotopic gliomas. Mean ± standard deviation shown. n = 3; statistical analysis: Student t test. (C) In vitro platelet aggregation (percentage) of platelets incubated with astrocytes isolated from control and Astro^PDPN-KO mice. Mean ± standard deviation shown. n = 3; statistical analysis: Student t test. (D) CD61 and laminin staining (brown) of sections from DKO-NSCs orthotopic tumors in Astro^Ctrl (mice carrying Pdpn-flox alleles) and Astro^PDPN-KO mice. The sections were counterstained with hematoxylin. Scale bars, 100 µm. Quantification of tumor area covered by CD61 (E) and laminin (F) staining. Mean ± standard deviation shown. n = 4; statistical analysis: Student t test. *P < .05; **P < .01.