Condroitinase ABC e células tronco mesenquimais no tratamento de Rattus norvegicus submetidos a trauma agudo da medula espinhal

Abstract

The spinal cord injury affects people and animals causing sensory and motor deficits that greatly affect the quality of life and, in the case of animals, often lead to euthanasia. The treatment of this condition is a challenge for researchers because there is still no effective therapy for this complex pathology. In this context, the use of stem cells as a therapeutic resource appears particularly promising, because in addition to secrete neurotrophic factors, these cells can differentiate into neurons and glial components, however these actions appear to be harmed by the glial scar formed after spinal cord injury. The bacterial enzyme chondroitinase ABC is able to digest this scar which could favor the action of these cells as well as axonal regeneration. The present study aimed to evaluate the effect of chondroitinase ABC and bone marrow mesenchymal stem cells in single or combination therapy, in the treatment of rats subjected to spinal cord injury. Fifty Rattus norvegicus were divided into five groups. The animals in the negative control group (CN) underwent laminectomy, while the others suffered addictionaly spinal cord compression and were treated with placebo (PLA), chondroitinase ABC (CDT), bone marrow mesenchymal stem cells (CTM) or chondroitinase and stem cells associated (CDT + CTM). The chondroitinase or placebo were administered intralesionally, seven days after laminectomy, while the stem cells, or placebo, were injected intravenously 14 days after laminectomy. The animals were assessed for motor skills and, 30 days after laminectomy, proceeded to euthanasia and subsequent verification of histopathological changes in the spinal cord. The spinal cords were also evaluated by PCR for quantification of gene expression of BDNF, NT-3, VEGF, KDR, PECAM-1 and caspase 3; and by immunohistochemistry to detect the injected stem cells (anti-GFP) and quantification of astrocytes (anti-GFAP), neurons (anti-NeuN) and vimentin.There was no statistical difference in motor ability of animals subjected to trauma. The group CTM had the highest gene expression of BDNF and VEGF. There was no statistical difference between treatments for the gene expression of NT-3, KDR, PECAM -1 and caspase-3. In immunohistochemistry, labeling of neurons was higher in the CDT + CTM compared to PLA. Immunostaining for GFAP was higher in PLA and CDT+CTM than in CN. As for immunostaining of vimentin, the CN was lower and differed from all groups with trauma, and among these, CDT showed the lowest expression. It was concluded that the mesenchymal stem cells were effective in promoting increased expression of trophic factors BDNF and VEGF. The chondroitinase ABC was effective in reducing glial scar, verified by immunostaining of vimentin. There was no synergistic effect on use associated stem cells with chondroitinase.