Supplementary Figure 2: rNLS8 microglia are capable of responding to inflammatory triggers.

(a-b) Representative cryosections of SC from a nTg mouse (a) and an rNLS8 mouse (b) stained with IBA-1 (red) to label microglia shows reactive gliosis on the ipsilateral (left) side 6 days after sciatic nerve crush similarly for both mice, demonstrating that rNLS8 microglia can appropriately react to inflammatory triggers. (c-f) Zoomed in images of an nTg and rNLS8 SC, left (c,e) and right (d,f) ventral horns show the neurons containing hTDP-43 (blue) and activated or resting microglia interspersed among them. Similar results were obtained from 4 rNLS8 and 4 nTg mice. (g) Dot plot shows the microglia density differences in the crushed side (black dots) versus the uncrushed side (blue dots), which are similar for both nTg and rNLS8 mice; group means indicated with a red line, n = 4 per group, ***, paired, two-tailed t-test with d.f. = 3, t = 13.8, p = 0.0008 and t = 12.8, p = 0.001, between crushed and uncrushed sides of rNLS8 and nTg mice, respectively. (h) Dot plot showing no difference in hTDP-43 expression in MNs on crushed (black) versus control (blue) side of the rNLS8 SC with group means indicated with a red line, n = 4. Scale bar = 100 μm. (i-k) rNLS8 and nTg have similar inflammatory responses to peripheral injection with LPS. Representative cryosections of SC from 1 of 4 nTg and 1 of 4 rNLS8 mice injected with PBS (i) or LPS (4 mg/kg, i.p.) and sacrificed 6 hours (j) or 18 hours (k) later, stained with IBA-1 (red), shows a slight, time-dependent activation of spinal microglia, regardless of hTDP43ΔNLS transgene expression. Scale bar = 100 μm.