Fig. 3

Late-phase MMP-9 in female and male nerves post-CCI. a von Frey testing in female and male rat CCI ipsilateral and contralateral to injury in hind paws. The graph represents the mean withdrawal thresholds (gram force, g) ± SEM, displaying significant allodynia in both female and male animals at day 28 post-CCI in the ipsilateral hind paw (*p ≤ 0.05). b The status of catalytic MMP-9 activity in the sciatic nerve in female and male rats. Gelatin zymography of the purified MMP-9 samples (from 25 μg total extract each; PURIFIED) isolated at day 28 post-CCI contralateral (day 0) and ipsilateral (day 28 post-CCI) to injury (representative of n = 4/group). c Left panel: MMP-9 immunostaining (red) in the sciatic nerve in female and male rats at 4 weeks post-CCI (representative of n = 3/group). Scale bar, 50 μm. Right panel: MMP-9 (red) and S100 (green) dual immunostaining in female nerve demonstrates that Schwann cells (white arrows) and other cells (blue arrowheads) produce MMP-9 at day 28 post-CCI. Scale bar, 25 μm