Transplantation Of BMSCs Overexpressing Bcl-2 Protein Promotes Functional Recovery In Rats With Spinal Cord Injury

Objective SCI is a common catastrophic injury,leading to lifelong severe disability.Research on the treatment of SCI has become a major medical topic of global concern.BMSCs have immunomodulatory and neurotrophic effects.BMSCs transplantation can effectively promote the recovery of neurological function in SCI.However,the survive of BMSCs after transplantation and the rate of differentiation into nerve cells are limited.Bcl-2 has shown great importance in cell apoptosis and nerve differentiation,it plays a key role in axon growth and regeneration.The purpose is investigating the effect of Bcl-2 overexpresion on BMSCs survival and transplantation.Methods This project mainly involves two aspects.In vitro,primary BMSCs were extracted from rats and identified by flow cytometry flux.The multiple differentiation ability of BMSCs was verified by special induction medium.Bcl-2 overexpressing BMSCs were constructed by lentivirus infection,Cells were divided into Bcl-2-BMSCs group with overexpression of Bcl-2,vector-BMSCs group with empty Vector transfection,and BMSCs group without transfection.WB was used to detect the protein expression of Bcl-2 and h BCL-2 in each group to prove the success of transfection.CCK-8 was used to detect cell activity and survival under the condition of FBS deprivation.Bcl-2 overexpressing BMSCs were cultured in M1-CM,and the expression of Cleaved Caspase3 was detected by ICC.In vivo experiments,clamped SCI rat model was established,and BMSCs overexpressing Bcl-2 were transplanted into the lesion area three days after SCI,and motor function recovery of SCI rats was evaluated by BBB score in 4 weeks after SCI.2 weeks after SCI,HE staining were used to evaluate the tissue recovery of spinal cord.Results Flow cytometry flux results showed the cells were BMSCs.BMSCs show the potential to differentiate into osteoblasts adipocytes and chondrocytes under continuous induction conditions.The expression of Bcl-2 in Bcl-2-BMSCs group was significantly higher than that in the other two groups,and h Bcl-2 was only expressed in this group.Overexpression of Bcl-2 increased the cell activity of BMSCs and improved the survival of BMSCs under serum deprivation,and could counter the apoptosis induced effect of M1-type macrophages.After BMSCs transplantation,the overexpression of Bcl-2 showed more limited tissue damage area in 14 days after SCI.BMSCs with overexpression of Bcl-2 were beneficial to functional recovery of SCI rats since 4 days after transplantation,and the transplantation of BMSCs with overexpression of Bcl-2 was better than BMSCs transplantation alone.Conclusion Overexpression of Bcl-2 can promote the survival of BMSCs.Transplant of BMSCs with overexpression of Bcl-2 can reduce the damage of spinal cord tissue in SCI rats and facilitate the functional recovery.