MiR-126 Promotes The Proliferation And Differentiation Of Endogenous Neural Stem Cells After Spinal Cord Injury

Objective:The effects of miR-126 on the proliferation and differentiation of endogenous neural stem cells(ENSCs)and the repair of motor function in mice after spinal cord injury(SCI)were observed from molecular,histological and overall level.Methods:The spinal cord contusion model of 10 thoracic spinal cord(T10)was made by MASCIS Impactor M-III.The motor function was assessed by Basso Mouse Scale(BMS)score at different times after injury;Then,Hematoxylin-Eosin staining(HE)and Nissl's staining were used to observe histopathological and Nissl body changes in the injury site,and the number of ENSCs was detected by immunofluorescence technic(IF);Immunohistochemistry(IHC)was used to detect the number of positive cells expressed by HOXA9;The expression of miR-126,Nestin and HOXA9 was detected by Real-time PCR(RT-PCR),and the expression of corresponding protein was detected by Western Blotting(WB).Results:In the acute phase of SCI in mice,the expression of mir-126 decreased,but over time,the expression of mir-126 gradually increased,and the expression of Nestin showed the same trend,while the expression of HOXA9 was opposite.In the acute stage of injury,a large number of inflammatory cells infiltrated and neurons were lost.The motor function of mice was restored with the increase of neuron number.Conclusion: 1.miR-126 promotes the proliferation of ENSCs after SCI in mice.2.miR-126 promotes the differentiation of ENSCs into neurons by negative regulation of the expression of HOXA9.3.miR-126 promotes the repair of motor function after spinal cord injury in mice.