Fig. 1

Pro-inflammatory cytokines are up-regulated in response to ALS-CSF: exposure of astrocytes to ALS-CSF caused a progressive up-regulation in the secretion of IL-6 (a; *p < 0.05 NC v/s ALS, 48 h; n = 3 in duplicates), TNF-α (b; **p < 0.01 NC v/s ALS, 24 and 48 h; n = 3 in duplicates), and IFN-γ (c; *p < 0.05, 24 h and **p < 0.01 NC v/s ALS, 48 h; n = 3 in duplicates), while a down-regulation in the IL-10 levels was observed (d; **p < 0.01 NC v/s ALS, 24 and 48 h; n = 3 in duplicates). The protein levels were determined by ELISA. e–p The confocal images representing the cellular expression of the cytokines in the normal controls as compared to the cultures exposed to NALS/ALS-CSF. Analysis of the mean fluorescence intensity (MFI) revealed a qualitative as well as a quantitative increase in the expression of IL-6 (green, e–g; graph q; *p < 0.05 NC v/s NALS and ALS; n = 5 in duplicates) and TNF-α (red, h–j; graph r, #p < 0.05 NC v/s ALS and **p < 0.01 NALS v/s ALS; n = 5 in duplicates). However, the cellular levels of IFN-γ (red, k–m; graph s; n = 5 in duplicates) and IL-10 (green, n–p; graph t; n = 5 in duplicates) did not show any significant changes in the cultures exposed to ALS-CSF. Graphs u–w represent the mRNA expression levels of IL-6, IFN-γ, and IL-10, respectively, in response to ALS-CSF. Note the up-regulation in IL-6 (**p < 0.01 NC and ^# p < 0.05 NALS v/s ALS; n = 3 in triplicates; u), IFN-γ (**p < 0.01 NC and NALS v/s ALS; n = 3 in triplicates; v), and IL-10 mRNA expression (*p < 0.05 NC v/s ALS; n = 3 in triplicates; w) when exposed to ALS-CSF. Analysis of significance was carried out using Student’s t test for ELISA and one-way ANOVA followed by Tukey’s post hoc test for determining the MFI as well as the mRNA expression. Scale bars for confocal images are indicated