Figure 1.
GFAP overexpression during MA.
(A) GFAP levels in 4d, 7d and 14d MA animals were always higher in the ipsilateral DRGs (lines 3, 5, 7) when comparing to DRGs from the contralateral side (lines 4, 6, 8). As expected, control values were similar for both ipsi and contralateral sides (lanes 1 and 2). (B) The ratios between Ipsi and Contralateral GFAP levels (GFAP/actin values) were significantly increased at day 7 and 14 days of MA which suggests activation of SGCs at around 1 week after disease induction. (C) Single immunolabeling for GFAP (red) specifically in SGCs, in a L5 DRG from a 7d MA animal (bar represents 20 µm). D) The percentage of the total number of GFAP-positive neuronal profiles in the total neuronal population (GFAP+total NP/NPtotal) significantly increases at 7d MA. All values are shown as Mean±SEM, In B) N = 6 for controls and N = 5 for all the other experimental groups. * represents p<0.05 relatively to controls. One-way ANOVA was followed by Tukey's Multiple Comparison post-hoc test. In D) N = 5 for all experimental groups.** represents p<0.01, relatively to controls. One-way ANOVA was followed by Bonferroni post-hoc test.
Figure 2.
GFAP labeling in SGCs surrounding ATF3 positive neurons increases at 7d MA.
(A, B) Double labeling for ATF3 (green) and GFAP (red), in L5 DRGs sections from a control (A) and a 7d MA animal (B). (C) The percentage of double labeled neuronal profiles in the total neuronal population (% Double+total/NPtotal) increases at 7d MA. (D) The percentage of double labeled neuronal profiles in the total ATF3-positive neuronal population (Double+total/ATF3+total) also increases after 7d MA, even though ATF3-positive neurons represent a small portion of the total neuronal population of the DRG (%ATF3+total/NPtotal). In A and B, the bar represents 50 µm, # identifies a single labeled GFAP-positive neuronal profile, § identifies a single labeled ATF3-positive neuron and* identifies co-labeling of both GFAP and ATF3. In C and D, all values are shown as Mean±SEM with N = 5 for 7dMA and N = 4 for controls. * Represents p<0.05 relatively to control animals. One-tailed Student's t-test analysis.
Figure 3.
BrdU incorporation increases during MA.
(A–I) Immunofluorescence labeling for GS (red) (A, B, C), BrdU (green) (D, E, F) and respective colocalization between both (G, H, I), in a L5 DRG of a control and a 7d MA animal (bar represents 100 µm). Arrows point to well visible double-labeled SGCs. An amplified image from a L5 DRG of a 7d MA animal shows BrdU labeling in detail (bar represents 20 µm) (C, F, I). (J) The number of proliferating SGCs (SGCs+), in the total number of neuronal profiles (SGC+total/NPtotal), significantly increases at 7d MA. (K) The mean number of proliferating SGCs around a specific neuron (Mean SGC+/NP) also increases at 7d MA. (L) The number of positive neuronal profiles (NP+total/NPtotal) is also significantly higher in 7d MA, when compared with both control non-inflamed and to 4d MA animals. All values shown as Mean±SEM. N = 6 for controls and 7d MA, and N = 5 for 4d MA experimental group.* Significant differences relatively to control. # Significant differences relatively to 4d MA.* or # represents p<0.05; ** represents p<0.01. One-way ANOVA was followed by Newman-Keuls Multiple Comparison post-hoc test.
Table 1.
SGCs significantly proliferate at 7d of MA.