Implantaion Of Neurotrophin Gene Transduced Bone Direved Mescenchymal Stem Cells To Repair Spinal Cord Injury In Adult Rats

The present study uniquely combines mesenchymal stem cells (MSCs) implantation with neurotrophin gene therapy in an attempt to enhance regeneration and functional recovery after thoracic spinal cord complete injury in adult rats. Primary MSCs were transduced with reconstructed vectors encoding rat brain-derived neurotrophic factor (BDNF) or human neurotrophin-3 (NT-3).The main results as follows:1. MSCs were isolated from wistar rat red marrow. After several passages culture, clone culture, induced Osteoblastic differentiation and adipocytic differentiation were observed. We found that the cells could form typical cell clones during clone culturing, and mineral deposition was widely distributed in the culture dish 3 weeks after osteoinductive culture, also O Red oil positive staining lipid droplets were detectable after adipoinductive culture.2. After an optimized neuron differentiation induced procedure, the cells presented typical neuron like shape. And 1 week later, over 70% of the cells were MAP-2 immunohistochemical positive stain.3. 2 months after transplantation of Hoechst stain MSCs allograft following spinal cord semi-transection injury, there were dense transplanted cells surrounding the inject position and transferred into the center of the injury site. A few of the cells expressed the mark proteins of neurons and astrocytes.4. Within 5 weeks after spinal cord semi-transection in rats, MSCs could tend to and assemble in injury site of spinal cord.5. Implantation of MSCs transduced with a BDNF- or NT-3 encoding vector significantly enhanced regenerative sprouting of the fibers and recovery of hind limb function after thoracic spinal cord completely injury, and both expression of BDNF and NT-3 get better results.The results demonstrate that neurotrophin genetic engineering of MSCs not only resulted in a cell that was more effective in promoting axonal outgrowth but could also lead to enhanced recovery after spinal cord injury, and cells transplantation combined two genes therapy may result in better effect.