Figure 3.

IDH1^WT GBM cell-derived conditioned medium transforms primary microglia to an immunosuppressive phenotype by activating Wnt/β-catenin signaling. (a) Schematic illustration of the treatment of primary microglia with IDH1^WT or IDH1^MUT GL261 glioma cell-derived conditioned medium (CM). Primary microglia were cultured with CM from IDH1^WT cells (CM-WT) or IDH1^MUT cells (CM-MUT) for 24 h, while the control group was cultured in normal F12/DMEM (NM). (b) Immunoblots showing CD163, Wnt3a, GSK-3β and β-catenin in primary microglia treated with IDH1^WT or IDH1^MUT GL261 glioma cell-derived conditioned medium (CM). Primary microglia were cultured with CM from IDH1^WT cells (CM-WT) or IDH1^MUT cells (CM-MUT) for 24 h, while the control group was cultured in normal F12/DMEM (NM) (n = 4). Mean±SD are shown. (c) Flow cytometric analysis of CD11b⁺CD45^low cells in primary microglia treated with CM (n = 4). Mean±SD are shown. (d) Representative white light and immunofluorescence images of primary microglia cultured in NM, CM-WT and CM-MUT for 24 h. CD163 and β-catenin are displayed in green and red, respectively. The nuclei were stained with DAPI (blue) (n = 4). Student’s t-test. Scale bar: 50 μm. ***p < .001. exp.: expression. NM: normal F12/DMEM medium; CM: conditioned medium; CM-WT: conditioned medium from IDH1^WT cells; CM-MUT: conditioned medium from IDH1^MUT cells