Exosomal LncRNA–NEAT1 derived from MIF-treated mesenchymal stem cells protected against doxorubicin-induced cardiac senescence through sponging miR-221-3p

Background: The chemotherapy drug doxorubicin (Dox) is widely used for treating a variety of cancers. However, its high cardiotoxicity hampered its clinical use. Exosomes derived from stem cells showed a therapeutic effect against Dox-induced cardiomyopathy (DIC). Previous studies reported that exosomes derived from mesenchymal stem cells (MSCs) pretreated with macrophage migration inhibitory factor (MIF) (exosome MIF ) showed a cardioprotective effect through modulating long noncoding RNAs/microRNAs (lncRNAs/miRs). This study aimed to investigate the role of exosome MIF in the treatment of DIC. Results: : Exosomes were isolated from control MSCs (exosome) and MIF-pretreated MSCs (exosome MIF ). Regulatory lncRNAs activated by MIF pretreatment were explored using genomics approaches. Fluorescence-labeled exosomes were tracked in vitro by fluorescence imaging. In vivo and in vitro, miR-221-3p mimic transfection enforced miR-221-3p overexpression, and senescence-associated β-galactosidase assay was applied to test cellular senescence. Exosomal delivering LncRNA-NEAT1 induced therapeutic effect in vivo was confirmed by echocardiography. It demonstrated that exosomes MIF recovered the cardiac function and exerted the anti-senescent effect through LncRNA–NEAT1 transfer against Dox. TargetScan and luciferase assay showed that miR-221-3p targeted the Sirt2 3'-untranslated region. Silencing LncRNA–NEAT1 in MSCs, miR-221-3p overexpression or Sirt2 silencing in cardiomyocytes decreased the exosome MIF -induced anti-senescent effect against Dox. Conclusions: : The results indicated exosome MIF serving as a promising anti-senescent effector against Dox-induced cardiotoxicity through LncRNA–NEAT1 transfer, thus inhibiting miR-221-3p and leading to Sirt2 activation. The study proposed that exosome MIF might have the potential to serve as a cardioprotective therapeutic agent during cancer chemotherapy.