RÉSUMÉ
BACKGROUND: At present, treatments for spinal cord injury are limited, with poor outcomes. Therefore, it is of great importance to explore new treatment methods. OBJECTIVE:To observe the therapeutic effect of bone marrow mesenchymal stem cells(BMSCs)injection via the caudal vein on spinal cord injury in rats. METHODS:BMSCs were isolated and cultured in vitro by whole bone marrow adherence method.The surface markers were identified by flow cytometry. Thirty Sprague-Dawley rats were randomly divided into control group, spinal cord injury group and BMSCs transplantation group, 10 rats in each group. A rat spinal cord injury model was established by occlusion of the 10ththoracic vertebra using an aneurysm clamp, and 2×106BMSCs were injected through the caudal vein at 10 minutes after modeling. Basso-Bettle-Bresnahan (BBB) score for motor function recovery was assessed at 0, 10, 20, 30 days after transplantation. The therapeutic effect was evaluated by hematoxylin-eosin staining and electron transmission microscopy at 30 days after implantation. RESULTS AND CONCLUSION: Under the microscope, fusiformis-shaped or fibroblast-like cells were observed. The expression rate of CD44 and CD90 was more than 90% and the expression of CD45 was less than 2%, by which, the BMSCs were identified. The BBB scores were significantly higher in the BMSCs transplantation group than the spinal cord injury group at 20 and 30 days after transplantation (P < 0.05). Hematoxylin-eosin staining showed that there was spinal cord tissue damage, vascular rupture injury, neuronal cell degeneration and inflammatory cell infiltration in the spinal cord injury group. After BMSCs transplantation, the number of spinal cord neurons was markedly increased with intact cytomembrane and clear nucleolus. Electron microscopic results showed that spinal cord axon swelling, demyelination, nerve axon deformation and necrosis were observed in the spinal cord injury group, while after BMSCs transplantation, the rat spinal cord axon structure was repaired,and partially lost myelin was recovered with uniform thickness.To conclude,BMSCs transplantation via the caudal vein has a significant therapeutic effect on spinal cord injury in rats by repairing the spinal cord structure and protecting the integrity of axon and myelin structures.
RÉSUMÉ
BACKGROUND: Until now, there is no effective treatment for peripheral neuropathy caused by acrylamide. Therefore, it is necessary to explore new treatment methods. OBJECTIVE: To explore the protection role and its mechanism of bone marrow mesenchymal stem cells (BMSCs) against acrylamide-induced intoxication in the spinal cords of rats. METHODS: BMSCs were cultured by the whole bone marrow adherence method and identified by morphological observation and flow cytometry detection. Thirty Sprague-Dawley rats, clean grade, were randomly divided into three groups (n=10 for each group): normal control group, acrylamide group and BMSCs transplantation group. The latter two groups received acrylamide by gavage, 50 mg/(kg?d), 5 days per week, for 2 weeks with an interval of 2 days. Then, in the BMSCs transplantation group, 3×106BMSCs were transplanted by the caudal vein, 5 days per week, for 3 consecutive weeks. Hematoxylin-eosin staining was utilized to observe the morphological changes of the spinal cord. Tunel assay was used to detect cell apoptosis. Western blot assay was adopted to detect the expression levels of Bcl-2 and Bax. RESULTS AND CONCLUSION: In the acrylamide-exposed rats, the damage to the structure was found in the spinal cords by morphological observation, which was significantly alleviated after BMSCs transplantation. The disturbed expression levels of Bax and Bcl-2 were also significantly inversed after BMSCs transplantation (P < 0.05). These results suggest that BMSCs transplantation can inhibit cell apoptosis in the spinal cords of acrylamide-intoxicated rats, probably by up-regulating expression of Bcl-2 and down-regulating expression of Bax.