Exosomal derived from human umbilical cord mesenchymal stem cells alleviates coxsackievirus B3-induced cardiomyocyte ferroptosis via the SMAD2/ZFP36 signal axis.

Viral myocarditis (VMC) is one of the most common acquired heart diseases in children and teenagers. However, its pathogenesis is still unclear, and effective treatments are lacking. This study aimed to investigate the regulatory pathway by which exosomes alleviate ferroptosis in cardiomyocytes (CMCs) induced by coxsackievirus B3 (CVB3). CVB3 was utilized for inducing the VMC mouse model and cellular model. Cardiac echocardiography, left ventricular ejection fraction (LVEF), and left ventricular fractional shortening (LVFS) were implemented to assess the cardiac function. In CVB3-induced VMC mice, cardiac insufficiency was observed, as well as the altered levels of ferroptosis-related indicators (glutathione peroxidase 4 (GPX4), glutathione (GSH), and malondialdehyde (MDA)). However, exosomes derived from human umbilical cord mesenchymal stem cells (hucMSCs-exo) could restore the changes caused by CVB3 stimulation. was enriched in hucMSCs-exo, and the inhibitory effect of hucMSCs-exo on CVB3-induced ferroptosis was higher than that of hucMSCs-exo (NC: negative control). Mothers against decapentaplegic homolog 2 (SMAD2) increased in the VMC group, while the expression of zinc-finger protein 36 (ZFP36) decreased. was confirmed to interact with messenger RNA (mRNA), and the SMAD2 protein interacted directly with the ZFP36 protein. Silencing and overexpressing inhibited the expression of ferroptosis-related indicators. Meanwhile, the levels of GPX4, solute carrier family 7, member 11 (SLC7A11), and GSH were lower in the overexpression plasmid (oe-)+ mimic group than in the oe-NC+ mimic group, while those of MDA, reactive oxygen species (ROS), and Fe increased. In conclusion, these data showed that ferroptosis could be regulated by mediating expression. Exo- derived from hucMSCs could mediate to promote the expression of ZFP36, which further inhibited the ferroptosis of CMCs to alleviate CVB3-induced VMC.