Effects of repulsive guidance molecule B on functional recovery after spinal cord injury in rats

Abstract:

Objective：To explore the expression rule of repulsive guidance molecule B（RGMB） after spinal injury in rats and its cor－relation with the spinal cord functional recovery. Methods：Totally 65 adult male SD rats were divided into A，B，C groups randomly. Chondroitin sulfate（chondroitinase ABC，ChABC） enzyme was not applied to do degradation in group A（n=25）. ChABC was used to do degradation in group B（n=20）. Only spinal cord was exposed in group C（n=20）. Body movements were recorded in three groups at the same postoperative time points. Rats were executed to do specimen detection. Basso-Beattie-Bresnahan（BBB） score was used to evaluate the feeling and movement of rat’s hindlegs. HE staining was employed to calculate the total damage. Real-time PCR was used to detecte RGMB mRNA expression.Immunofluorescence staining was used to observe the double standard expression of glial fibrillary acidic protein（GFAP） and neurofilament-200（NF-200）. Results：Within the same period at 2-4 weeks after the injury，BBB score was obviously higher in group B than in group A（P＜0.05）. Two weeks after the injury，HE staining demonstrated hollow formation in A and B groups；damaged area was significantly smaller in group B than in group A（P＜0.05）. At 2-4 weeks after the injury，GFAP/NF-200 double immunofluorescence staining demonstrated that GFAP expression was gradually lower in group B and immunofluorescence intensity value was significantly higher in group A than in group B（P＜0.05）；NF-200 positive staining fibers passed through the damaged area and immunofluorescence intensity value was significantly higher in group B than in group A（P＜0.05）. RGMB mRNA expression was decreased in group B than in group A（P＜0.05）. Conclusions：After spinal cord injury in rats，RGMB concentration in the microenvironment is negatively correlated with the spinal cord functional recovery. RGMB in－hibitors may be helpful for clinical treatment of spinal cord in－jury.