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

Jun Gu, Zheng Shuai Jin, Chun Ming Wang, Xue Fei Yan, Yuan Qing Mao, Sheng Chen The Affiliated Jiangsu Shengze Hospital of Nanjing Medical University, Suzhou 215228, People’s Republic of ChinaCorrespondence: Sheng Chen Tel +8618013798189Email rylnjmu@sina.comBackground: 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.Keywords: bone marrow mesenchymal stem cells, exosomes, spinal cord injury, apoptosis, autophagy