2022, Vol. 26 ›› Issue (20): 3190-3195

Vimentin silenced by small interfering RNA inhibits glial scar formation in a rat model of acute spinal cord injury

Li Jianfeng1, Zhang Shulian2, Yan Jinyu2, Li jiayi1, Jin Zhao1, Deng Qi2   

Abstract: BACKGROUND: A barrier with formation of glial scar after spinal cord injury is considered to be harmful for nerve repair.
OBJECTIVE: To explore the influence of small interfering RNA (siRNA)-mediated inhibiting Vimentin on reactive astrocytes and on the formation of glial scar after central nervous system injury.  
METHODS: Third-generation astrocytes that grew well were selected and randomized into untransfected group, siRNA-NC group, and siRNA-Vimentin group. We used siRNA interference technology to silence vimentin expression in astrocytes, and Vimentin immunofluorescence staining was conducted at 24 hours after transfection. Cell migration and proliferation were observed through a cell scratch test. Sprague-Dawley rats were randomized into a control group (n=10), in which only the lamina was opened, without damage to the spinal cord; a model group (n=20), in which a spinal cord injury model was prepared, followed by direct injection of saline and empty plasmids into the spinal cord; and a treatment group (n=20), in which the spinal cord injury model was prepared followed by direct injection of Vimentin plasmids intervened with siRNA for 24 hours. Spinal cord continuity and thickness as well as scar adhesion with surrounding tissues were observed at 1 day, 4, and 8 weeks after surgery.
RESULTS AND CONCLUSION: Integral asorbance value of Vimentin by fluorescence immunoassay was lower in the siRNA-Vimentin group than the untransfected and siRNA-NC groups (P < 0.05). The scratched width was larger in the siRNA-Vimentin group than the untransfected and siRNA-NC groups. The spinal cord tissue structure at the injured site was improved in the treatment group, and the range of glial scar formation was smaller in the treatment group than the model group at 4 and 8 weeks after surgery. To conclude, Vimentin has a significant inhibitory effect on the proliferation and migration of reactive astrocytes and inhibits the formation of glial scars after spinal cord injury, providing a favorable microenvironment for axonal regeneration and nerve function recovery after spinal cord injury.
Key words: small interfering RNA, Vimentin, reactive astrocyte, glial scar, spinal cord injury