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

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.

Mesenchymal Stem Cells Alleviate Post-resuscitation Cardiac and Cerebral Injuries by Inhibiting Cell Pyroptosis and Ferroptosis in a Swine Model of Cardiac Arrest

“…Another two studies demonstrated that MSC-derived exosomes attenuated myocardial injury by inhibiting cardiac ferroptosis through promoting miR-23a-3p-mediated suppression of divalent metal transporter 1 expression and modulating the pumilio RNA binding family member 2/peroxiredoxin 6 axis, respectively ( Song et al, 2021 ; Zhang et al, 2021 ). In the setting of cerebral IR injury, one study demonstrated that MSC-derived exosomes decreased microglial pyroptosis by enhancing forkhead box O3a-mediated mitophagy and subsequently alleviated neuronal injury under hypoxia/reoxygenation ( Hu et al, 2021 ). Another one study demonstrated that MSC-derived exosomes alleviated cerebral I/R injury by inhibiting neuron pyroptosis through modulating microglial polarization ( Liu X et al, 2021 ).…”

Huc-MSCs-derived exosomes attenuate inflammatory pain by regulating microglia pyroptosis and autophagy via the miR-146a-5p/TRAF6 axis

“…Although the analgesic effects may be related to inhibiting the activation of neurons and glial cells, the definite mechanism remains elusive. Recently, another study showed that huc-MSCs-derived exosomes protected microglia from pyroptosis by enhancing mitophagy [ 24 ]. Another study also showed that huc-MSCs-derived exosomes protected against DSS-induced colitis via inhibiting the activation of NLRP3 inflammasomes and subsequent pyroptosis [ 13 ].…”

Neuropeptide Y in the amygdala contributes to neuropathic pain-like behaviors in rats via the neuropeptide Y receptor type 2/mitogen-activated protein kinase axis

“…The cells were transfected according to the aforementioned grouping with three repeated wells set for each group. After 0, 24, 48, 72 and 96 h of culture, 10 μL CCK-8 solution was added into each well, followed by incubation for 2 h. The optical density value was then determined at 450 nm using a microplate reader [ 31 ].…”