Effect of lentiviral vector of microRNA-9-1 on differentiation of mouse bone marrow mesenchymal stem cells into neurons

AIM: To investigate the role of microRNA-9 in inducing bone marrow mesenchymal stem cell(MSCs) differentiation into neurons. METHODS: The lentiviral vector of microRNA-9-1(microRNA-9-1-LV) was constructed and transfected into mouse MSCs.The cells were divided into non-transfected group,transfected group(transfected with microRNA-9-1-LV) and negative control group(transfected with FU-RNAi-NC-LV).MSCs were treated with β-mercaptoethanol(β-ME) as an inducer for triggering the cells to differentiate into neurons.The fluorescence expressed by transfected MSCs were observed under inverted fluorescence microscope.The mRNA expression of microtublin-associated protein 2(MAP-2) was detected by RT-PCR.The expression of neuron-specific markers,neuron-specific enolase(NSE),MAP-2 and glial fibrillary acidic protein(GFAP),were measured by immunocytochemical method.The viability of MSCs was determined by MTT method. RESULTS: The results of PCR confirmed successful construction of mouse microRNA-9-1-LV.The virus titer was 1×1012 TU/L(TU,transduction unit).The best transfection efficiency(up to 91.3%±4.2%) and survival rate appeared when multiply of infection(MOI)was 20 and on 4th day.β-ME induced MSCs to differentiate into neurons and the best efficiency of the induction was observed in transfected group.The expression levels of NSE and MAP-2 in transfected cells were higher than those in the cells of other group(P0.05). CONCLUSION: MicroRNA-9-1-LV has high transfection efficiency in mouse MSCs.Higher differentiation rate from mouse MSCs to neurons is induced by β-ME after the cells are transfected with microRNA-9-1-LV.