Fig. 1

EVs isolated from GSCs decrease radiation-induced senescence and promote motility in HMVECs. A. Evaluation of β-gal and H2AX positive irradiated HMVECs (50 Gy) by immunohistochemistry (up) and immunofluorescence (down), respectively. The arrows point out senescent endothelial cells; arrowheads point out β-gal negative cells. Quantification of positive cells was shown (lower panel). Scale bar: 30 μm B. Immunohistochemical evaluation of CD31 and β-gal positive cells in normal mouse brain (upper panel), irradiated mouse brain with trauma injury (center panel) and irradiated mouse brain grafted with U87MG cells (lower panel). Scale bar: 100 μm upper panel, 30 μm center and lower panels. C FACS analysis based on green fluorescence of HMVECs after GSC-derived C16-EV uptake (shaded histogram = HMVEC control sample; open histogram = HMVECs incubated with EVs). D Measurement of β-gal positive irradiated HMVECs (50 Gy) relative to sham irradiated cells (CTRL, dashed line at value 1). HMVECs (50 Gy), HMVECs incubated with GSC-derived EVs (50 Gy + EVs) and HMVECs incubated with irradiated GSC-derived EVs (50 Gy + 50 Gy EVs) are shown. Results are shown as mean ± SD from two independent experiments. ns, not significant; *p < 0.05 vs HMVECs 50 Gy (Student’s t test). E. Scratch-wound assay quantification (left) and images (right) of HMVECs, HMVECs incubated with GSC-derived EVs and HMVECs incubated with irradiated GSC-derived EVs at 0 h and 24 h time points. Values are reported as the percentage wound area and shown as mean ± SD from two independent experiments. **p < 0.01 vs HMVECs (Student’s t test) (scale bar: 600 μm; magnification 4X)