Localisation and expression of C3/C3b in hSOD1G93A and wild-type mice during disease progression. (A) mRNA expression profile of C3 in lumbar spinal cord of hSOD1G93A mice relative to wild-type (WT) mice. Dashed line, baseline expression in WT controls at each time point. (B) Degree of immunolabelling for C3b significantly increased in the lumbar spinal cord of hSOD1G93A mice at end stage when compared with WT mice. (A, B) Data expressed as mean ± standard error of the mean (n = 6 mice/group; *P <0.05, **P <0.01, ***P <0.001, Student t test). (C) to (T) Double immunolabelling of C3b (red) with cellular markers (green) for motor neurons (ChAT; (C) to (E) WT mice, (L) to (N) hSOD1G93A mice), astrocyte (glial fibrillary acidic protein (GFAP); (F) to (H) WT mice, (O) to (Q) for hSOD1G93A mice), and microglia (Iba-1; (I) to (K) WT mice, (R) to (T) hSOD1G93A mice) in the ventral lumbar spinal cord of WT and hSOD1G93A mice (end stage). C3b immunolabelling was absent on motor neurons in WT mice (C to E), but was present on motor neurons in hSOD1G93A mice (white arrows in L and N (detailed in U)). There was minimal co-localisation of C3b with Iba-1-labelled microglia in WT (white arrows in I and K). In hSOD1G93A mice immunolabelling of C3b was evident in Iba-1-labelled microglia (white arrows, R and T (detailed in W)). There was no co-localisation with C3b and GFAP-positive astrocytes in WT and hSOD1G93A mice (F to H for WT, O to Q (detailed on V) for hSOD1G93A mice). PS, pre-symptomatic; OS, onset; MS, mid-symptomatic and ES, end-stage. Scale bars for all panels = 20 μM.
Lee et al. Journal of Neuroinflammation 2013 10:119 doi:10.1186/1742-2094-10-119