AIM: To study the changes of brain-derived neurotrophic factor(BDNF)expression in gene modified bone marrow mesenchymal stem cells(BMSC).

METHODS: BMSC were divided into blank control group(without transfected BMSC), negative control group(empty vector without BDNF gene transfected BMSC)and experimental group(BDNF gene transfected BMSC). The expression of BDNF mRNA in BMSC was measured by Realtime PCR, and the expression of BDNF in BMSC was measured by ELISA.

RESULTS: The BDNF mRNA expressions of 3, 4, 5, 6, 7 and 8-generation BMSC cells in the experimental group were higher than those in the blank control group and negative control group. The differences were statistically significant(P3: F=491.788, P<0.05; P4: F=380.112, P<0.05; P5: F=1854.929, P<0.05; P6: F=224.540, P<0.05; P7: F=619.155, P<0.05; P8: F=10.092, P<0.05). As the BMSC cells in the experimental group passaging, the BDNF mRNA expressions in the experimental group decreased. The difference of BDNF mRNA expression among different passage cells was statistically significant(F=298.603, P<0.05). The BDNF secretion of 3, 4, 5, 6, 7 and 8-generation BMSC cells in the experimental group were higher than those in the blank control group and negative control group. The differences were statistically significant(P3: F=520.609, P<0.05; P4: F=734.520, P<0.05; P5: F=152.847, P<0.05; P6: F=80.372, P<0.05; P7: F=96.083, P<0.05; P8: F=38.532, P<0.05). As the BMSC cells in the experimental group passaging, the BDNF secretion decreased. The difference of BDNF secretion among different passage cells was statistically significant(F=230.084, P<0.05).

CONCLUSION: Long-term expression of BDNF in BMSC can be enhanced by genetic engineering.