Repair Of Spinal Cord Injury In Rats By Subarachnoid Transplantation With Bcl-2 Gene Modified Schwann Cell

BACKGROUND:Spinal cord injury(SCI)is a difficult to repair traumatic disease.In basic research and clinical practice,researchers have taken a number of ways to repair damaged spinal cord,such as promoting axonal regeneration,reducing inhibition Factor,transplantation of peripheral nerves,reconstruction of arc and so on,but the results are not satisfactory.Studies have shown that spinal cord injury after spinal cord nerve cell loss,decreased neurotrophic factor secretion,damage in the presence of various factors to inhibit axonal functional regeneration,spinal cord axon regeneration is difficult and difficult to restore the main reason for the recovery minus.Spinal cord injury,nerve tissue regeneration difficulties,the main reason is the secondary damage continues to increase,but secondary damage is complex,mostly due to the process of participation,which plays a very important role in apoptosis.The effect of Schwann cells(SC)on the regeneration of central nervous system cells after spinal cord injury has been confirmed,which has a role in promoting functional recovery after spinal cord injury.3,4 Schwann cells can secrete neurotrophic factors,The role of phagocytic scar tissue and local necrotic tissue.The study of repairing spinal cord injury in Schwann cells is becoming more and more important,and has become a hotspot in recent years.The programmed cell death process is also one of the factors that affect spinal cord injury to apoptosis.There is evidence that the genes involved in the regulation of cell apoptosis are mainly pro-apoptotic genes and apoptotic genes.Bcl-2 plays an important role in apoptosis,high levels of expression of bcl-2 gene can effectively prevent tissue apoptosis,such as hepatocellular carcinoma.With the development of genetic engineering technology,exploring the use of genetic means to treat spinal cord injury has become one of the modern researchers' treatment.Successful introduction of therapeutic genes into host cells ensures a high level of gene expression,which has become the key to gene therapy.However,the use of bcl-2 gene transfected Schwann cells in the treatment of spinal cord injury is not sufficient.This study was designed to investigate the effect of bac-2 gene modified Schwann cell subarachnoid transplantation on neurological function recovery after spinal cord injury in rats.OBJECTIVE:To investigate the effect of bcl-2 gene transfection of Schwann cell subarachnoid transplantation on the recovery of neurological function in rats with spinal cord injury.METHODS:Schwann cells were cultured in vitro and transfected into Schwann cells by Ad-EGFP as the vector.The expression of bcl-2 gene was transfected into Schwann cells.The rats were divided into 3 groups:control group,negative transfection group And bcl-2 transfection group.Western blot was used to detect the expression of bcl-2 protein on the 3rd and 14th day after transfection.83 adult female SD rats were randomly divided into control group,SCs group and bcl-2-SCs group(n = 24).The model of acute spinal cord injury was established according to the modified Allen strike method.BBB,inclined plate test and modified Tarlov method were performed before,1 day,3 days,1 week,2 weeks,3 weeks and 4 weeks after modeling.Rats in each group were evaluated for motor function.The expression of glial fibrillary acidic protein(GFAP)and neurofilament protein(NF-200)around the spinal cord injury area was detected by RT-PCR and Western blot.The apoptosis of nerve cells was detected by TUNEL method.The survival and distribution of SCs labeled with EGFP were observed by HE staining and fluorescence microscopy.HRP retrograde tracing was used to detect the repair of nerve fibers.The electrophysiological recovery of the rats was observed by SEP and MEP.Western blot analysis showed that Ad-EGFP-mediated bcl-2 gene transfection of schwann cells in vitro stable expression of bcl-2;rat lower limb motor function evaluation bcl-2-SCs group than SCs group,SCs group Better than the control group.The number of apoptotic cells in bcl-2-SCs group was significantly lower than that in the other two groups(P<0.05).Compared with control group and SCs group,the expression of GFAP,NF-200 gene and protein in bcl(4)after modeling,HE staining control group without spinal cord loss and syringomyelia formation,no nerve axon through.In the SCs group,a small amount of The bcl-2-SCs group showed more axonal structure and no syringomyelia.EGFP-labeled positive cells:bcl-2-SCs group was more than SCs group(P<0.05).At 4 weeks after the control group,the difference between the groups(P<0.05)(P<0.05).The amplitude of bcl-2-SCs group was significantly higher than that of the control group(P<0.05)SCs group>control group,the latency of SEP and MEP was significantly different between the two groups(P<0.05)And the difference between the groups was significant(P&It;0.05).CONCLUSION:bcl-2 gene modified Schwann cell transplantation can promote the regeneration of neuronal synapses in spinal cord injury rats,increase the expression of GFAP,NF-200 gene and protein in spinal cord injury area,reduce neuronal apoptosis in spinal cord injury area,The limb motor function and electrophysiological function of the mouse.