Experiment Research On The Treatment Of Spinal Cord Injury With Lentiviral Vectors-mediated P27^kip1 Expression

Objective To study the role of p27^kip1 overexpression in cell cycle and spinal cord injury. Providing further support for the therapeutic potential of cell cycle inhibitors in the treatment of SCI.Methods We expressed the CDK inhibitor p27^kip1 by Lentiviral vectors（LV） in the lesioned spinal cord of adult rat. Locomotor function was assessed using the Basso, Beattie and Bresnahan（BBB） scale and combined behavioral score（CBS）. All functional scores and spinal cord tissue was obtained at different time point. Using Western Blot, Immunohistochemistry, Immunofluorescence, cell culture to investigate the role of LV-p27^kip1 in spinal cord injury.Results The western-blot showed that p27^kip1 expression was significantly increased in LV-p27^kip1 treated rats compared with sham group after injury indicating transgene p27^kip1 overexpression. Western blot also showed that LV-p27^kip1 treatment significantly reduced the cell cycle related protein levels after SCI. BBB and CBS scores showed that LV-p27^kip1 treatment significantly increased scores after injury. Meanwhile, LV-p27^kip1 decreased astrocytic reactivity, attenuated microglial activation, reduced cell death, and enhanced expression of MBP. In vitro, p27^kip1 overexpression reduces astrocyte migration.Conclusions LV construct can be used as an efficient vector to introduce p27^kip1 into the injured spinal cord. By transducing cells in the spinal cord with the p27^kip1, we observed improved functional recovery, decreased astrocytic reactivity, microglial activation, cell death, and improved the local microenvironment.