Fig. 3

Legumain mRNA expression is upregulated in the caudal spinal cord after SCI.

(A) Quantitative real-time PCR (qPCR) shows that legumain mRNA expression increases from 3 days post-injury and remains upregulated at 11 days after SCI. (B) In situ hybridization for legumain 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, legumain mRNA is only observed in neurons. In the lesion site, legumain mRNA is observed in many small cells at all time points tested after SCI. In the spinal cord caudal to the lesion site, legumain mRNA is detectable in small cells in both the sham-injured and SCI groups at 1 day, with a stronger signal for legumain mRNA after SCI compared to the sham injury group. At 3 days, while the signal for legumain mRNA in small cells is not detectable anymore in the sham-injured group, strong positive signal for legumain 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, n = 3 experiments; B, n = 4 fish for each group. * P<0.05, two-way ANOVA with Tukey′s post hoc test; mean values ±SEM are shown. Scale bar, 50 μm.