Bone Marrow Mesenchymal Stem Cell-Derived Exosomes Improves Spinal Cord Function After Injury in Rats by Activating Autophagy

Background: Spinal cord injury (SCI) is a global medical problem. The smallest membrane-bound nanovesicles, known as exosomes, have a role in complex intercellular communication systems and can be used directly as therapeutic agents by acting as important paracrine factors. Nevertheless, the use of exosomes derived from BMSCs (BMSC-Exos) to treat SCI has been less, and the specific mechanism has not yet been reported. Methods: BMSC-Exos were characterized by TEM, NTA and Western blot. The effects of BMSC-Exos treatment were compared by SCI in vivo model and a series of in vitro experiments. Results: BMSC-Exos were found to enhance the expression of autophagy-related proteins LC3IIB and Beclin-1 and enabled autophagosomes formation. After BMSC-Exos treatment, there was marked decline in the level of expression of proapoptotic protein cleaved caspase-3, while that of the antiapoptotic protein BcL-2 was upregulated. Conclusion: BMSC-Exos can attenuate neuronal apoptosis by promoting autophagy and promote the potential efficacy of functional behavior recovery in SCI rats. In summary, these findings expand the theoretical knowledge and forms a realistic route for the future treatment of SCI by BMSC-Exos.