Objective To explore the feature of BMSC exosomeson sensory conduction function recovery post dorsal column injury. Methods BMSC exosomes were extracted from Wistar rats. 36 rats were randomly divided into sham, PBS control, and exosomes groups.The exosomes group was injected with exosomes via the tail vein, and the PBS control group was injected with the same amount of PBS. Tape removal test and somatosensory evoked potential were used to evaluate sensory conduction function. The spinal cord dorsal column was observed by immunofluorescence staining, and Western Blot was used to detect STAT3 and GAP43 protein expression. Results Immunofluorescence staining showed that the extracted BMSC could express CD29 and CD90. Western Blot showed that HSP70 and Alix were highly expressed in the extracted exosomes. Compared with the PBS control group, the exosomes group had a larger NF-200 staining area, and improved the waveform of somatosensory evoked potential and latency in tape removal test. The expression of STAT3 and GAP43 protein was significantly increased in exosomes group. Conclusion BMSC exosomes can promote the recovery of sensory conduction function of rats with spinal cord dorsal column lesion through STAT3/GAP43 pathway.

Objective: To explore the effects of bone marrow mesenchymal stem cell (BMSC) exosomes on STAT3/GAP43 pathway and axonal growth of primary sensory neurons. Methods: BMSC of Wistar rats was extracted and the cell morphology was observed and identified by light microscope. Hypercentrifugation was used to extract BMSCs exosomes and identified the exosomes. Primary sensory neurons (rat dorsal root ganglion neurons) were treated with BMSC exosomes, immunofluorescence staining was used to detect axon growth of primary sensory neurons, and Western Blotting to detect STAT3 and GAP43 protein expression in primary sensory neurons. Results: Immunofluorescence staining showed that the extracted cells expressed CD29 and CD90 simultaneously, which proved the extracted cells were BMSC. Western Blotting showed the extracted exosomes expressed HSP70 and Alix. Compared with the control group, the length of neuronal axon in BMSC exosomes group increased significantly, the expression of STAT3 and GAP43 protein also significantly increased in BMSC exosomes group (P<0.05). Conclusions: BMSC exosomes can promote axonal growth of primary sensory neurons by regulating STAT3/GAP43 pathway.