Study On The Effect And Mechanism Of Bone Mesenchymal Stem Cell Transplantation On 2,5-hexanedione Induced Apoptosis In Spinal Cord Of Rats

Objective The purpose of this study was to investigate the effects and mechanism ofbone mesenchymal stem cells transplantation on 2,5-Hexanedione induced apoptosis in spinal cord of rats.Materials and Methods 3 to 4-week-old male SD rats were used for bone marrow mesenchymal stem cell isolation.A total of 100 adult male SD rats were randomly divided into 5 groups:Control group,MSC group,HD group,HD-NS group and HD-MSC group,20 rats per group.Rats of the Control and MSC group were treated with 0.9%saline(0.3 ml/100g,intraperitoneal);HD,HD-NS and HD-MSC group were treated with 2,5-HD at a dosage of 400mg/kg/day(0.3ml/100g,intraperitoneal)for 5 weeks.5 weeks latter,Control and HD-NS group were treated with saline,MSC group and HD-MSC group were transplanted with MSCs at 5×107/kg per group.Using TUNEL assay to detect the cell apoptosis in spinal cord.qRT-PCR was used to detect the NGF gene in spinal cord.The alterations of NGF,TrkA,p-TrkA,Akt,p-Akt,Bad,p-Bad and cytochrome c proteins in spinal cord were detected by Western Blot.Using coimmunoprecipitation to detect the interactions between Bad and Bcl-xL in the Mitochondria.The activity of Caspase-3 was detected by activity kit.The experimental results were analyzed by using SPSS 17.0 statistical package.Results TUNEL analysis indicate that TUNEL positive cells in HD group are significantly higher than Control group(P<0.05),and HD-MSC group significantly decreased compared to HD group(P<0.05).The apoptosis indices of HD-MSC group is 2.25%,which is significantly higher than HD(14.54%)group(P<0.05).The results of qRT-PCR showed that NGF mRNA expression increased in HD-MSC group and significantly higher than HD group(P<0.05).The results of western bolt showed that the expression of p-TrkA,p-Akt,p-Bad increased in HD-MSC group and significantly higher than HD group(P<0.05);There is no significant change in the expression of TrkA,Akt and Bad;The results of coimmunoprecipitation showed that the dimerization of Bad/Bcl-xL in the mitochondrial fraction of HD-MSC group were decreased and significantly lower than HD group(P<0.05).The release of cytochrome c protein from mitochondria to cytosol was significantly decreased in HD-MSC group.The activity of Caspase-3 was significantly decreased in the HD-MSC group than that in HD group(P<0.05).Conclusion MSCs transplantion can reduce cell apoptosis in spinal cord of rats exposured to 2,5-HD.The potential anti-apoptotic effects of MSCs transplantion may be relevant with the NGF-mediated PI3K/Akt/Bad pathway.