HIIT reversed microglial polarization and mitigated inflammatory responses in OA rats
TMEM119 was a key indicator of microgliosis. We respectively detected TMEM119 in the microglia by immunofluorescence in control, OA, and OA+HIIT rats. The expression level of Tmem119 was significantly higher in OA rats than in control rats, and HIIT decreased its expression level (P  < 0.001, Figure 4A). In addition, we detected the expression of CD68 and CD163 to distinguish pheno-typic transformations of microglia. The flow cytometry results showed that the expression level of CD68 was higher in the OA group than in the control group. However, CD163 was significantly lower in the OA group compared with the control group, and the expression level of CD163 was higher in the OA+HIIT group than in the OA group (P  < 0.01, Figure 4B). Moreover, OA+HIIT exhibited decreased expression levels of Glu, c-fos, SP and IL-6 compared with OA rats (P  < 0.05, Figure 4C).