USP19 regulates microglial M1/M2 polarization by deubiquitinating FOXO1 to activate IL-10/IL-10R1 signaling. (A) The protein levels of USP19, FOXO1, IL-10 and IL-10R1 were detected by Western blot. (B) The ubiquitination of FOXO1 was monitored by co-IP. (C) SH-SY5Y cells were co-cultured with BV2 cells. (D) The expression of IBA1 and M1/M2 markers were detected by IF with quantitative analysis. (E) The apoptosis of SH-SY5Y cells were assessed by Annexin V-FITC/PI staining. (F) The secretion of cytokines in SH-SY5Y cells was detected by ELISA assay. (G) The protein levels of SOD and Gpx in SH-SY5Y cells were determined by Western blot. *, P < 0.05; **, P < 0.01; ***, P < 0.001.