<i>Legumain</i> mRNA expression is upregulated in the caudal spinal cord after SCI.

<p>(A) Quantitative real-time PCR (qPCR) shows that <i>legumain</i> mRNA expression increases from 3 days post-injury and remains upregulated at 11 days after SCI. (B) <i>In situ</i> hybridization for <i>legumain</i> mRNA in the caudal spinal cord shows different expression patterns in the lesion site (area with stripes) and the caudal part of spinal cord (area with dots). In the non-injured spinal cord, <i>legumain</i> mRNA is only observed in neurons. In the lesion site, <i>legumain</i> mRNA is observed in many small cells at all time points tested after SCI. In the spinal cord caudal to the lesion site, <i>legumain</i> mRNA is detectable in small cells in both the sham-injured and SCI groups at 1 day, with a stronger signal for <i>legumain</i> mRNA after SCI compared to the sham injury group. At 3 days, while the signal for <i>legumain</i> mRNA in small cells is not detectable anymore in the sham-injured group, strong positive signal for <i>legumain</i> mRNA expression is observed in small cells in the SCI group. At 11 days, more positive neurons are seen after SCI compared to the sham-injury group. No signal is detectable with the sense probe. Rostral is left and caudal is right. A, <i>n</i> = 3 experiments; B, <i>n</i> = 4 fish for each group. * <i>P</i><0.05, two-way ANOVA with Tukey's <i>post hoc</i> test; mean values ±SEM are shown. Scale bar, 50 µm.