RESUMO
Multi-target neural circuit-magnetic stimulation has been clinically shown to improve rehabilitation of lower limb motor function after spinal cord injury. However, the precise underlying mechanism remains unclear. In this study, we performed double-target neural circuit-magnetic stimulation on the left motor cortex and bilateral L5 nerve root for 3 successive weeks in a rat model of incomplete spinal cord injury caused by compression at T10. Results showed that in the injured spinal cord, the expression of the astrocyte marker glial fibrillary acidic protein and inflammatory factors interleukin 1ß, interleukin-6, and tumor necrosis factor-α had decreased, whereas that of neuronal survival marker microtubule-associated protein 2 and synaptic plasticity markers postsynaptic densification protein 95 and synaptophysin protein had increased. Additionally, neural signaling of the descending corticospinal tract was markedly improved and rat locomotor function recovered significantly. These findings suggest that double-target neural circuit-magnetic stimulation improves rat motor function by attenuating astrocyte activation, thus providing a theoretical basis for application of double-target neural circuit-magnetic stimulation in the clinical treatment of spinal cord injury.
RESUMO
OBJECTIVE: To study the effect of bone marrow mesenchyml stem cell (BMSC) exosomes (Exo) on the proliferation and migration of brain microvascular endothelial cells in rats. METHODS: BMSCs were extracted from rats and identified. The BMSCs were co-cultured with bEnd.3 cells in Transwell chamber for 24 h (BMSCs group). Extracted and identified the BMSCs exosomes (BMSC-Exo). Observed and qualitatively evaluated the cells' abilities on swallowing the BMSC-Exo under a fluorescence microscope. The optimal work concentration of BMSC-Exo was selected by detecting the cell vitality under different BMSC-Exo concentrations by CCK8 method. bEnd.3 cells were co-cultured with BMSC-Exo for 24 h (BMSC-Exo group). bEnd.3 cells cultured alone was set as control group. The proliferation and migration of bEnd.3 cells in the three groups were respectively detected by EDU and cell scratching experiment after 24 h of culture. RESULTS: Flow cytometry showed that P3 BMSCs were CD90 and CD29 positive and CD45 negative, with osteogenic differentiation and adipogenesis differentiation, indicating the extracted BMSCs high purity. The BMSC-Exo under transmission electron microscopy was round-shaped with a diameter of about 100 nm; NTA analysis found the diameter distribution of BMSC-Exo ranged from 50 to 600 nm, with a peak size of 150 nm. Immunofluorescence showed that the endothelial cells could swallow BMSC-Exo. CCK8 showed that supplement of 20 µg/mL BMSC-Exo had the best effect on cell proliferation. EDU results showed that BMSCs group and BMSC-Exo group could promote the proliferation of bEnd.3 cells compared with the control group (P<0.05), and there was no difference between BMSCs group and BMSC-Exo group (P>0.05). Cell scratch test showed that the cell mobility of the BMSC-Exo group was higher than that of the control group (P<0.05), but there was no significant difference between the BMSC-Exo group and the BMSCs group (P>0.05). CONCLUSION: BMSC-Exo can replace BMSCs in effectively promoting the proliferation and migration of cerebral microvascular endothelial cells, which provide a new potential treatment for angiogenesis after stroke.