OBJECTIVETo study the effects of miR-124-1 on neuronal differentiation of rat bone marrow mesenchymal stem cells (MSCs).

METHODSMSCs cells were assigned into three groups: control (uninfected and untransfected), miR-124-1+ (infected with miR-124-1), and miR-124-1- (transfected with Anti-rno-miR-124* Inhibitor). MSCs were induced by β-mercaptoethanol (β-ME) to differentiate into neurons. The fluorescence expressed by infected MSCs was observed under an inverted fluorescence microscope. MTT method was used to measure cell survival rate after transfection or infection. Immunocytochemistry, RT-PCR and Western blot methods were used to detect the expression of β3 tubulin, MAP-2 and GFAP 6 days after β-ME induction.

RESULTSThe expression of miR-124-1 in the miR-124-1+ group was significantly higher 2 days after infection of lentivirus vector compared with the control group (P<0.01). In the miR-124-1- group, the cell survival rate and the miR-124-1 expression level decreased significantly 24 hrs after transfection of anti-rno-miR-124* inhibitor (P<0.01). After 6 days of β-ME induction, the protein and mRNA expression levels of β3 tubulin and MAP-2 in the miR-124-1+ group were much higher than the other two groups (P<0.01); while the expression levels of β3 tubulin and MAP-2 in the miR-124-1-group were lower than the control group (P<0.01). The expression of GFAP in the three groups was weak (<1%).

CONCLUSIONSmiR-124 might promote neuronal differentiation of rat MSCs.