The Study On The Expression Of Nogo-A Protein In Acute Spinal Cord Injury Rats Treating With Bone Marrow-derived Mesenchymal Stem Cells And Methylprednisolone Associated

Objective:By studying the expression of Nogo-A protein and the effect of neurological rehabilitation in acute spinal cord injured rats which were treated with homogenous bone marrow-derived mesenchymal stem cells(BMSCs) and methylprednisolone associated to investigate the mechanisms of BMSCs in improving neuro-rehabilitation.Methods:A Sprague-Dawley(SD) rat which was three weeks of age and 100g of weight was killed to extract and culture the bone marrow-derived mesenchymal stem cells used percoll gradient centrifugation and adhesion method.According to transect spinal cord injury(SCI) at the T10 model to make 100 acute spinal cord injured SD rats,which were randomly four groups:control group(group A,n=25),MP group(group B,n=25),BMSCs group(group C,n=25),BMSCs and MP associated group(group D,n=25).Behavior test was carried out on the 5 rats from each group at 1 hour before spinal cord surgery,1day,7days,14days,21days,28days after surgery using the BBB (Basso,Beattle,Bresnahan) scores.Then,we cut out the specimens and examine the expression of the neurofilaments(NF) by using the immunohistochemical technique.The other rats of the four groups according to the SCI were divided into 3days,7days,14days,21days subgroups.At the injured sites of corresponding group,we pumped BMSCs with microinjector at the injured sites in group C and D.We injected MP by tail nein in early stage after SCI in group B and D.All rats were killed at the corresponding time and its myeloid tissue was take out. we cut out the specimeins to examine the expression of Nogo-A by using the immunohistochemical technique.All the results were analyzed by one-way anovo of analysis.Results:1,The expression levels of Nogo-A protein raised up at the first time and broke down later after spinal cord injury,The transcriptional levels of Nogo-A protein achieved the peak at the time 7 days after spinal cord injury;2,The expression Nogo-A protein broke down apparently when used MP,BMSCs,MP and BMSCs associated respectively compared to the control group.Compared to MP group,the expression of Nogo-A decreased apparently in the BMSCs group,the associated group broke down apparently than other groups.There was a significant statistically difference between them(P＜0.05);3,All animals in the injury group showed a paralysis on their hindlimbs.The BBB scores were higher in the MP group,BMSCs group and associated group than the control group at the time points of 14 days, 21 days,28 days.Compared to the MP group,the BBB scoreshigher in the BMSCs group,the scores highest in the associated group.There was a significant statistically difference between them(P＜0.05).4,The NF immunohistochemical examination demonstrated that the relative gray values of the associated group is higher than other groups. There was a significant statistically difference between them(P＜0.05).Conclusions:1,The MP and BMSCs can protect the spinal cord and promote its repair after spinal cord injury,maybe through affecting the expression levels of Nogo-A and NF protein;2,There is a synergetic effect in the MP and BMSCs transplantation associated.