Fig. 4

Expression of C5a and C5aR1 in the spinal cord of TDP-43^Q331K mice at three different ages of disease progression. a The protein expression of C5a in the spinal cord of non-transgenic (NTg, orange bars), TDP-43^WT (green bars) and TDP-43^Q331K (blue bars) at 16 months. b mRNA expression of C5aR1 in the spinal cord of TDP-43^Q331K mice relative to age-matched NTg and TDP-43^WT mice at 3, 10 and 16 months of age. Data are expressed as means ± SEM (n = 5 mice/group, *P < 0.05, ***P < 0.001, ****P < 0.0001, one-way ANOVA with Tukey’s post hoc test for each age). c–k Double immunolabelling of C5aR1 (red) with cellular markers (green) for motor neurons (ChAT; c–e), microglia (Iba-1; f–h) and astrocyte (GFAP; i–k) in the ventral lumbar spinal cord of NTg, TDP-43^WT and TDP-43^Q331K mice at 16 months of age. C5aR1 was co-localised with ChAT-positive motor neurons (c–e, white arrows) and microglia (f–h, white arrows) in NTg, TDP-43^WT and TDP-43^Q331K mice. Note that white arrows indicate red and green fluorescent signal merge to orange. Scale bars for all panels = 20 μm