RESUMO
BACKGROUND: Traumatic optic nerve injury is an important cause of vision loss, and the treatment methods are relatively limited. In order to find a better treatment method, this experiment started from the direction of microglia. Under neuropathological conditions, activation of microglia can maintain the stability of the central nervous system, but excessive activation of microglia can produce a large number of inflammatory factors that progressively aggravate the damage. OBJECTIVE: To investigate the activation of microglia after optic nerve injury and the effect of bone marrow mesenchymal stem cells (BMSCs) on the overexpression of microglia. METHODS: There were 18 Sprague-Dawley rats, 8 weeks of age, which were divided into BMSCs transplantation group, model group and sham operation group, with 6 rats in each group. In the model group and BMSCs transplantation group, the rat’s left eye was selected to separate the retina and optic nerve after the optic clamping of the optic nerve. The sham operation group only separated the retina and optic nerve with no clamping. In the BMSCs transplantation group, the left eye vitreous body was injected with quantitative passage 3 BMSCs (1×108 cells, 2 μL) immediately after the injury. While in the model group and sham operation group, the same amount of PBS was injected into the vitreous body. All the rats were sacrificed at 15 days postoperatively. After perfusion and fixation, the retina with optic nerve was taken for hematoxylin-eosin staining and immunohistochemical detection. RESULTS AND CONCLUSION: The expression levels of Ox-42 and tumor necrosis factor α were significantly higher in the model group than in the sham operation group (P < 0.05), while the expression of Ox-42 and tumor necrosis factor α in the optic nerve and retina in the BMSCs group was decreased and almost the same to that in the sham operation group. Therefore, excessive activation of microglia is associated with optic nerve injury, and BMSCs can inhibit the excessive activation of microglia and release of inflammatory factors, thus protecting the retina and optic nerve from traumatic injury to some extent.