Bone marrow mesenchymal stem cell-derived exosomes carrying long noncoding RNA ZFAS1 alleviate oxidative stress and inflammation in ischemic stroke by inhibiting microRNA-15a-5p

Bone marrow mesenchymal stem cell (BMSC)-derived exosomes can prevent oxidative stress and inflammation in cerebral ischemia-reperfusion injury. This study intended to assess influences of BMSC-released exosomes on oxidative stress and inflammation following ischemic stroke.In vitro and in vivo models were developed using oxygen-glucose deprivation/reperfusion (OGD/R) and middle cerebral artery occlusion (MCAO), respectively. After exosome isolation, co-culture experiments of BMSCs or BMSC-derived exosomes and OGD/R-treated BV-2 cells were implemented to evaluate the impacts of BMSCs or BMSC-secreted exosomes on proliferation, inflammation, oxidative stress, and apoptosis. The gain-of-function experiments of ZFAS1 or microRNA (miR)-15a-5p were conducted to investigate the associated mechanisms. Besides, MCAO mice were injected with exosomes from BMSCs overexpressing ZFAS1 for in vivo verification. The binding of ZFAS1 to miR-15a-5p was assessed through dual-luciferase reporter gene assay.Co-culture with BMSCs accelerated proliferation and downregulated IL-1β, IL-6, and TNF-α in OGD/R-exposed BV-2 cells, accompanied by increased SOD level and decreased MDA level and apoptosis, all of which were nullified by inhibiting exosome secretion. Mechanistically, ZFAS1 bound to miR-15a-5p to negatively orchestrate its expression. In addition, BMSC-released exosomes or BMSC-secreted exosomal ZFAS1 augmented proliferation but reduced oxidative stress, apoptosis, and inflammation in OGD/R-exposed BV-2 cells, whereas these impacts of BMSC-released exosomal ZFAS1 were nullified by overexpressing miR-15a-5p. Moreover, BMSC-derived exosomal ZFAS1 diminished MCAO-induced oxidative stress, cerebral infarction, and inflammation in mice.Conclusively, BMSC-released exosomes might carry long noncoding RNA ZFAS1 to curb oxidative stress and inflammation related to ischemic stroke, which was possibly realized through miR-15a-5p inhibition.