Fig 2: Canonical PC markers and ECM genes are upregulated with brain EC co-culture. (A) Experimental design: primary brain PCs were labeled, co-cultured with bEnd.3 cells for 3 days, isolated by FACS sorting, and analyzed via qRT-PCR. (B) Localization of stained PCs within the co-culture with bEnd.3 cells. Scale bar, 200 µm. (C) Expression levels of Pdgfrb, Cspg4, Anpep, Abcc9, and Rgs5 in PCs cultured alone (PC only) and co-cultured with bEnd.3 cells (PC + EC). The data were normalized to Gapdh and analyzed with a two-sided Student’s t-test. Data are presented as mean ± SEM. The experiment was repeated 5 times, with each data point indicating a replicate. (D) Expression levels of Itga1, Itga7, Itgb5, Lama2, and Lama4 in PCs cultured alone (PC only) and co-cultured with bEnd.3 cells (PC + EC). The data were normalized to Gapdh and analyzed with a two-sided Student’s t-test. Data are presented as mean ± SEM. The experiment was repeated 6 times, with each data point indicating a replicate.

Fig 3: Dual inhibition of PDGFR and VEGFR-2 inhibits glioma growth and progression. The primary GBM was induced in Ntv-a;Ink4a-Arf-/-;Pten-/-;LSL-Luc donor mice by RCAS-mediated somatic gene transfer. Single-cell tumor suspension was implanted into recipient mice, followed by treatment. a Schematic approach. b Animal survival was monitored for 70 days after injection (n = 6–7 mice). MS median survival. P values were determined by log-rank tests. c Tumor growth was analyzed by whole-body bioluminescence imaging. Left, representative images. Right, quantitative analysis of integrated luminescence in tumors at day 32–38 (n = 3–6, mean ± SEM). P values were determined by Student’s t test. d Tumor sections were stained with H&E and imaged. Representative data are shown from 3–4 mice/group. Scale bar: 100 µm. e Tumor sections were immunostained with anti-CD31 antibody and imaged. Shown are representative images (n = 3–5 mice). Scale bar: 100 µm

Fig 4: Endothelial-specific deletion of PDGFR-b sensitizes glioma-associated ECs and tumors to anti-VEGF treatment. a–c Tie2-Cre;Pdgfrbfl/fl mice were generated by crossing Tie2-Cre mice with Pdgfrbfl/fl mice. a Schematic approach. b ECs were isolated from mouse aortas. Heart tissue and ECs were subjected to immunoblot analysis. c Mouse embryos were imaged (n = 5). d–h The primary GBM in Ntv-a;Ink4a-Arf-/-;Pten-/-;LSL-Luc donor mice was induced by RCAS-mediated somatic gene transfer. Single-cell tumor suspension was implanted into Pdgfrbfl/fl (WT) or Tie2-Cre;Pdgfrbfl/fl (PDGFR-ß-?EC) recipient mice, followed by treatment with B20 antibody and IgG. d Schematic approach. e Animal survival was monitored for 60 days after injection (n = 7 mice). MS median survival. P values were determined by log-rank tests. f Tumor growth was analyzed by whole-body bioluminescence imaging. Left, representative images. Right, quantitative analysis of integrated luminescence in tumors at day 25–28 (n = 3–6 mice, mean ± SEM). g Tumor sections were stained with H&E dyes. Representative data are shown (n = 3–4 mice). Scale bar: 100 µm. h Tumor sections were immunostained with anti-CD31 antibody. Left, representative images. Right, quantitative analysis of CD31 fluorescence area (n = 4–5 mice, mean ± SEM). Scale bar: 100 µm. i Tumor sections were immunostained with anti-CD31 and anti-FSP-1 antibodies. Representative images are shown (n = 4–5 mice). Scale bar: 100 µm

Fig 5: Reduced vascular structures around implanted microelectrode arrays at 28 days post-implantation. Chronic microelectrode implantation reveals specific insult to the endothelial component of the BBB, which may precede pericyte reactivity, vessel permeability, and leakage of plasma components. Blood vessels as well as vessel-bound pericytes are visualized by representative immunohistochemical stains for lectin (red) and PDGFR-ß (green) at 28 days post-implantation compared to contralateral (non-implant) side. Center of the probe hole is denoted by a white “x.” Scale bar = 100 µm.