A Study on the Role of miR-126 in the Repair Process after Spinal Cord Injury

Abstract

Background: Spinal Cord Injury (SCI) results in motor, sensory, and autonomic dysfunctions and causes social and economic problems. Surgery, medication, and stem cell transplantation are therapeutic strategies for SCI. The use of endogenous neural stem cells seems preferable due to their lower immune responses. miR-126 serves as a promising microRNA for reducing inflammation after SCI. It can promote angiogenesis and proliferation of neural stem cells Objectives: This study aimed to observe changes in miR-126 expression after SCI in an animal mice model. Methods: A total of 42 healthy adult FVB mice were divided equally into 7 groups (6 SCI model versus 1 control). At different periods following SCI establishment in the model groups, Basso Mouse Scale score (BMS), histopathological changes, and expression levels of miR-126 were evaluated in the model groups compared to the control one. Results:: The BMS score increased to a certain extent as the time after spinal cord injury progressed. HE and Nissl staining showed that the acute period (1-7 days) after spinal cord injury was characterized by neuronal loss, whereas the chronic phase (21st day) was characterized by scar and cavity formation. Compared with the control group, the model group exhibited decreased expression of miR-126 during the acute phase (days 1-7 post-SCI). However, its expression increased by 21th day after SCI. Conclusion: Overexpressed miR-126 can contribute to reduced SCI-related damages, which may result in the promotion of the growth and proliferation of neural stem cells as well as the repair of motor function.