Microglia activation stimulates bone marrow mesenchymal stem cells to release gliocyte-derived neurotrophic factor for protection of dopaminergic neurons / 中国组织工程研究

ABSTRACT

BACKGROUND: Studies are very few regarding the specific reaction of bone marrow mesenchymal stem cells (BMSCs) to activated microglia. Moreover, it remains unclear how MSCs maintain dopaminergic neuronal survival under specific microenvironment.OBJECTIVE: To explore the effect of BMSCs stimulated by activated microglia on dopaminergic neuron survival.METHODS: BMSCs were isolated from Wistar rats by attachment method, and in vitro cultured; microglia was activated, and dopaminergic neurons were cultured by enzyme digestion method. The experiment included 5 groups: BMSCs, microglia, lipopolysaccharide (LPS)+microglia; BMSCs+LPS+microglia groups, in which the dopaminergic neurons were cultured with corresponding culture medium; the dopaminergic neurons alone group was cultured with 10% fetal bovine serum+ DMEM/F12. The effect of different microenvironment on dopaminergic neuron survival and gliocyte-derived neurotrophic factor released from BMSCs were detected by immunofluorescence technique.RESULTS AND CONCLUSION: The release of gliocyte-derived neurotrophic factor in groups involving BMSCs was greater than corresponding control group. Tyrosine hydroxylase immunofluorescence showed that neuronal survival of dopaminergic neurons alone group was 15%, microglia group was 10%, LPS+microglia was 5%, but BMSCs+LPS+microglia group was 28%, significantly greater than the other groups (P < 0.05). In addition, survival of in vitro cultured dopaminergic neurons was decreased with increasing culture duration, but the survival of dopaminergic neurons in group involving BMSCs was significantly greater than corresponding control group. This indicates that microglia activation stimulated BMSCs to upregulate gliocyte-derived neurotrophic factor to prevent dopaminergic neurons from toxic injury, and inhibit delayed death of dopaminergic neurons.