Previous studies have shown that neural stem cell transplantation has the potential to treat Parkinson’s disease, but its specific mechanism of action is still unclear. Stromal cell-derived factor-1 and its receptor, chemokine receptor 4 (CXCR4), are important regulators of cell migration. We speculated that the CXCR4/stromal cell-derived factor 1 axis may be involved in the therapeutic effect of neural stem cell transplantation in the treatment of Parkinson’s disease. A Parkinson’s disease rat model was injected with 6-hydroxydopamine via the right ascending nigrostriatal dopaminergic pathway, and then treated with 5 μL of neural stem cell suspension (1.5 × 104/L) in the right substantia nigra. Rats were intraperitoneally injected once daily for 3 days with 1.25 mL/kg of the CXCR4 antagonist AMD3100 to observe changes after neural stem cell transplantation. Parkinson-like behavior in rats was detected using apomorphine-induced rotation. Immunofluorescence staining was used to determine the immunoreactivity of tyrosine hydroxylase, CXCR4, and stromal cell-derived factor-1 in the brain. Using quantitative real-time polymerase chain reaction, the mRNA expression of stromal cell-derived factor-1 and CXCR4 in the right substantia nigra were measured. In addition, western blot assays were performed to analyze the protein expression of stromal cell-derived factor-1 and CXCR4. Our results demonstrated that neural stem cell transplantation noticeably reduced apomorphine-induced rotation, increased the mRNA and protein expression of stromal cell-derived factor-1 and CXCR4 in the right substantia nigra, and enhanced the immunoreactivity of tyrosine hydroxylase, CXCR4, and stromal cell-derived factor-1 in the brain. Injection of AMD3100 inhibited the aforementioned effects. These findings suggest that the stromal cell-derived factor-1/CXCR4 axis may play a significant role in the therapeutic effect of neural stem cell transplantation in a rat model of Parkinson’s disease. This study was approved by the Animal Care and Use Committee of Kunming Medical University, China (approval No. SYXKK2015-0002) on April 1, 2014.

Objective To investigate the influence of co-culture of microglia and neural stem cells (NSCs) on differentiation from NSCs into dopaminergic neurons in vitro.Methods (1) The microglia from neonatal SD rats was purified and identified.After the NSCs were isolated from 14-day pregnant SD rats,the cells were cultured and identified.(2) The identified NSCs were randomly divided into 2 groups:simple NSCs culture group and NSCs+microglia co-culture group.After the cells in both groups were cultured for 6 days,immunofluorescence assay and Westem blotting were performed to detect the protein expression of TH,DAT and Pitx3,the factors associated with the differentiation and maturity of dopaminergic neurons.(3) PCR was used to detect the gene transcription of TH,DA T and Pitx3 in the cells from the 2 groups and differences were compared between the 2 groups.Results (1)The staining of CD1 1b/c in the microglia mixed cultured in the neonatal SD rats was positive,with a purity of above 95％;the staining of NSCs identified via nestin was positive in the 14-day pregnant SD rats.(2) The immunofluorescence assay showed that the amounts of positive proteins of TH,DAT and Pitx3 in the NSCs+microglia co-culture group were significantly larger than in the simple NSCs culture group (P＜0.05).The Western blotting showed that the protein expression levels ofTH,DAT and Pitx3 in the NSCs+microglia co-culture group were significantly higher than in the simple NSCs culture group (P＜0.05).(3) The PCR detection showed that the gene transcription levels of TH,DA T and Pitx3 in the NSCs+microglia co-culture group were significantly higher than in the simple NSCs culture group (P＜0.05).Conclusion Co-culture of NSCs and microglia via Transwell may promote differentiation from NSCs into dopaminergic neurons.