| [Objective]To investigate the changes of ROCK2, pERM and GAP-43expression and the intervention effect of fasudil on rats after acute spinal cord injury, and to discuss the possible mechanisms of fasudil in the repair of spinal cord injury, in order to provide experimental basis for clinical drug treatment of spinal cord injury.[Methods]The model of moderate spinal cord injury in rats was established by Allen method. Rats were divided randomly into3groups:group A received laminectomy only; group B received acute spinal cord injury; group C received fasudil treatment in addition to acute spinal cord injury. The subjects in group C received intraperitoneal injection of fasudil1h after ACSI with a dosage of10mg/kg/d for consecutive14days. The subjects in group A and group B received normal saline daily instead of fasudil with the same method. At day1,3,7,14and21post-operation, The nerve function of rats were observed and evaluated by BBB score in each group, The morphology of injured spinal cord was observed by HE staining. The expression and distribution of ROCK2, p-ERM and GAP-43protein were detected by immunohistochemistry staining and observed under microscope. The expression of ROCK2and p-ERM protein was detected by Western blot at each study time point.[Results]1. BBB score:The BBB score of group B and group C was significantly lower than that of group A, while group B is the lowest. The BBB score of Group C was significantly higher than group B, and showed statistically significant changes at day 7,14and21(P<0.05)2. HE staining:Haemorrhage, fragmentation of the central area, axon interruption and demyelination in the injury regional were found in group B at the early stage after ASCI in HE staining, and scar tissue was formed later. Group C had less structure damage, while group A has no significant structure changes.3. Immunohistochemistry:Compared with group A, the expression of ROCK2in group B and group C increased and reached a peak at day3and then decreased. The expression of ROCK2in group C was lower than that in group B,the difference was statistically significant at day1,3,7and14(P<0.05). Compared with group A, the expression of pERM in group B and group C increased and reached a peak at day7and then decreased. The expression of pERM in group C was lower than that in group B, the difference was statistically significant at day7and14(P<0.05). Compared with group A, the expression of GAP-43in group B and group C increased and reached a peak at day7and then decreased. The expression of GAP-43in group C was higher than that in group B, the difference was statistically significant at day7,14and21(P<0.05).4. Western Blot:The expression of ROCK2and pERM consistent with the trend of immunohistochemistry results. Compared with group A, the expression of ROCK2in group B and group C increased and reached a peak at day3and then decreased. The expression of ROCK2in group C was lower than that in group B, the difference was statistically significant at each time point (P<0.05). Compared with group A, the expression of pERM in group B and group C increased and reached a peak at day7and then decreased. The expression of pERM in group C was lower than that in group B, the difference was statistically significant at each time point (P<0.05).[Conclusions]1. The expression of ROCK2, pERM and GAP-43were significantly increased after acute spinal cord injury. The expression of ROCK2began to increase at day1and reached a peak at day3and then decreased; the expression of pERM and GAP-43began to increase at day1and reached a peak at day7and then decreased. 2. The expression of ROCK2and pERM were reduced after fasudil treatment, while the expression of GAP-43was increased after fasudil treatment in acute spinal cord injury. The motor function recovery of rats in the fasudil treatment group is much better than rats without fasudil treatment.3. Fasudil could improve the axonal regeneration and function recovery after spinal cord injury. The possible mechanisms of this effect is that fasudil may block the Rho/ROCK pathway by down-regulating the expression of Rock2and inhibit the abnormal activation of ERM which increase the expression of GAP-43,... |
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