Fig. 10

Ppt1 deficient (Ppt1^−/−) astrocytes drive microglial activation. Ppt1^−/− and wild type (WT) cultures were maintained as mixed glial (astrocyte and microglial) cultures to examine whether monoculture phenotypes were maintained under basal and stimulated (LPS or LPS/IFNγ) conditions. a Under basal conditions, the proportion of cells expressing the astrocyte marker glial fibrillary acidic protein (GFAP) expression was higher in Ppt1^−/− mixed glial cultures than in their WT counterparts. GFAP expression did not increase in WT or Ppt1^−/− mixed glial cultures following addition of LPS, but did increase in WT following stimulation with LPS/IFNγ. b Under basal conditions, compared to WT cultures, Ppt1^−/− astrocytes exhibited a larger cell body size, which was decreased dramatically in response to exposure to LPS/IFNγ but not LPS only. c The mean total cell number as indicated by DAPI staining was statistically significantly lower in Ppt1^−/− mixed glial cultures. d The percentage of Type 1 (resting, elongated) microglia was significantly higher in WT cultures under basal conditions than in Ppt1^−/− mixed glial cultures. e The percentage of Type 2 (activated, rounded) microglia was higher in Ppt1^−/− mixed glial cultures under basal conditions. In both WT and Ppt1^−/− mixed glial cultures the percentage of Type 2 microglia was increased following stimulation with LPS, or with LPS/IFNγ. f Ppt1^−/− microglia appear morphologically more activated in mixed glia cultures than in microglial cultures, as indicated by a significantly higher percentage of Type 2 microglia under both basal and stimulated (LPS) conditions in mixed glial cultures. (Data shown as Mean ± SEM using a one way ANOVA, n = 3)