Fig. 3

The effects of chemical depletion of microglia. Chemical depletion of microglia eliminated LPS-induced production of ROS and NO and astroglial PPP activation. The rate of ROS/NO production was expressed as percent increase in the fluorescent signal at 60 min compared with that at 0 min. The rate of ROS production in the secondary astroglial culture exposed to LPS (0.01 μg/mL) for 12 h (a ROS), and the rate of NO production in the secondary astroglial culture exposed to LPS (0.01 μg/mL) for 12 h (b NO). Open columns, untreated astroglia. Striped columns, Ara-C/LME-treated astroglia. Values are the means ± SD of six wells. n.s., not significant, ***P < 0.001 versus control (grouped t test). PPP flux in untreated astroglia (c PPP) and in microglia-depleted astroglia (d PPP) after 15-h exposure to various concentrations of LPS as indicated in the figure. PPP flux increased in untreated astroglia at LPS of 0.01 μg/mL, but not in microglia-depleted astroglia. Values are the means ± SD of four flasks. n.s., not significant, **P < 0.01 versus control (ANOVA followed by Dunnett’s test). Representative photographs showing immunofluorescent staining with DAPI (blue), GFAP (green), or Nrf2 (red) in the secondary astroglial cultures. LPS (0.01 μg/mL) for 12 h induced the nuclear translocation of Nrf2 in microglia-containing astroglia (e), but did not in microglia-depleted astroglia (f). Scale bar, 50 μm