Human Umbilical Cord Mesenchymal Stem Cell-Derived Exosomes Attenuate Oxygen-Glucose Deprivation/Reperfusion-Induced Microglial Pyroptosis by Promoting FOXO3a-Dependent Mitophagy

  • Oxid Med Cell Longev. 2021 Nov 2:2021:6219715. doi: 10.1155/2021/6219715.
Zhenzhen Hu  1 ,  Ya Yuan  2 ,  Xiuli Zhang  2 ,  Yifeng Lu  2 ,  Na Dong  3 ,  Xiuqin Jiang  1 ,  Jinjin Xu  1 ,  Datong Zheng  1  2  3
Affiliations
  • 1. Clinical Molecular Diagnostic Laboratory, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210003, China.
  • 2. The Second Clinical Medical School of Nanjing Medical University, Nanjing, Jiangsu 210011, China.
  • 3. Children's Health Center, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210003, China.
PMID: 34765084 DOI: 10.1155/2021/6219715
Abstract

Background: Mesenchymal stem cell-derived Exosomes (MSC-exos) have been recognized as a promising therapeutic strategy for neonatal hypoxic-ischemic brain damage (HIBD). Recently, microglial Pyroptosis was shown to play a vital role in the progression of neonatal HIBD. However, whether MSC-exos improve HIBD by regulating microglial Pyroptosis remains unknown.

Methods: Exosomes were isolated from human umbilical cord mesenchymal stem cells (huMSCs) and identified by transmission electron microscopy (TEM), western blot, and nanoparticle tracking analysis (NTA). BV-2 cells were subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) to induce microglial ischemia/reperfusion (I/R) in vitro. CCK-8, ELISA, western blot, and Hoechst 33342/PI double staining were performed to detect the Pyroptosis of BV-2 cells. Conditioned medium (CM) from BV-2 cells exposed to different treatments was used to investigate its effect on neuronal injury. Moreover, 3-methyladenine (3-MA) and mitochondrial division inhibitor-1 (mdi-1) were used to verify the involvement of Mitophagy in the protection of MSC-exos against OGD/R-induced Pyroptosis in BV-2 cells. Finally, FOXO3a siRNA was used to investigate the involvement of FOXO3a in MSC-exo-induced Mitophagy and Pyroptosis inhibition.

Results: Exosomes from huMSCs were successfully extracted. In OGD/R-exposed BV-2 cells, MSC-exos increased cell viability and decreased the expression of NLRP3, cleaved Caspase-1, and GSDMD-N as well as the release of IL-1β and IL-18. Compared with CM from OGD/R-exposed BV-2 cells treated with PBS, CM from OGD/R-exposed BV-2 cells treated with MSC-exos significantly increased the viability of SH-SY5Y cells and decreased LDH release. MSC-exos also increased the expression of TOM20 and COX IV in OGD/R-exposed BV-2 cells. Additionally, 3-MA and mdi-1 attenuated the inhibition of Pyroptosis with MSC-exo treatment. Furthermore, FOXO3a siRNA partially abolished the neuroprotective effect of MSC-exos and attenuated Mitophagy and Pyroptosis inhibition induced by MSC-exo treatment.

Conclusions: Our findings demonstrated that MSC-exos increased FOXO3a expression to enhance Mitophagy, therefore protecting microglia from I/R-induced Pyroptosis and alleviating subsequent neuronal injury.

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