Mitochondrial calcium uniporter and macrophage polarization. Gene expression of MCU (a) and MCUb (b) was examined in M0 (resting), M1- and M2-polarized macrophages and the ratio between expression of MCU and MCUb (c) was calculated (* p < 0.05 for the indicated comparison after ANOVA). Gene expression of The M1 marker IL1B (d) and of the M2 marker MRC (e) was examined in M0, M1, and M2 macrophage with or without treatment with the MCU inhibitor KB-R7943 (* p < 0.05 for the indicated comparison after ANOVA). Surface expression of the M1 marker CD80 (f) and of the M2 marker CD206 (g) was examined by flow cytometry in M0, M1, and M2 macrophages with or without treatment with the MCU inhibitor KB-R7943 (* p < 0.05 for the indicated comparison after ANOVA). (h) The ratio of the surface expression of CD80 over CD206, which is considered a proxy of M1 polarization, was examined in M2-polarized cells, with or without treatment with the MCU inhibitor KB-R7943 (* p < 0.05). (i) Representative FACS plots of CD80 surface expression in M1 (left) and CD206 expression in M2 (right) macrophages with or without treatment with the MCU inhibitor KB-R7943. (j) Efficiency of siRNA-mediated knockdown of MCU in cells transfected with scramble siRNA or siRNA against MCU (* p < 0.05). (k) The ratio of the surface expression of CD206 over CD80 was examined in M2-polarized cells, with or without MCU knockdown (* p < 0.05).