Fig. 7: CA treatment abolishes the effects of glia-secreted proinflammatory cytokines on neuronal damage and Aβ secretion.

A172 human glioblastoma cells were incubated with 1 µg/mL LPS for 24 h to trigger proinflammatory responses and then treated with CA at a final concentration of 1 µM for 12 h. A Western blot analysis was performed to evaluate the protein expression of IL-1β, IL-6 and TNFα. B The secretion of IL-1β, IL-6 and TNFα was measured by ELISA. C Representative blots showing the protein levels of COX-2, nuclear CEBPβ and NFκB in A172 cells. D SH-SY5Y cells overexpressing human APPswe or empty vector (neo) were cultured in LPS-primed cell-conditioned medium and treated with or without CA. The protein levels of nuclear NFκB and COX-2 were measured. E The mitochondrial transmembrane potential of APPswe and neo cells was determined by FCM. The percent of red and green fluorescence signal of JC-1 was measured to assess the degree of mitochondrial depolarisation. F Apoptosis of APPswe and neo cells were labelled by Annexin V-FITC/PI staining and analysed by FCM. G The secretion of Aβ40 and Aβ42 by APPswe and neo cells was measured by ELISA. The ratio of Aβ42 to Aβ40 was quantified. The data were representative of at least three independent experiments. *p < 0.05, **p < 0.01 and ***p < 0.001 vs untreated cells; ^#p < 0.05, ^##p < 0.01 and ^###p < 0.001 vs the LPS-stimulated group (A–C). **p < 0.01 and ***p < 0.001 vs the group treated with the medium of A172 cells not incubated with LPS (Control); ^#p < 0.05, ^##p < 0.01 and ^###p < 0.001 vs the group incubated with the medium of LPS-primed A172 cells without CA treatment; ^$p < 0.05, ^$$p < 0.01 and ^$$$p < 0.001 vs neo cells (D, G). Data were submitted to two-way ANOVA with Fisher LSD post hoc tests. Values represent the mean ± SD. All experiments were repeated at least three times.