Alterations of long noncoding RNAs and mRNAs in extracellular vesicles derived from the murine heart post-ischemia-reperfusion injury

Neonatal heart tissue-derived EVs alleviate adult ischemic cardiac injury via regulating the function of macrophages and cardiac regeneration in murine models

Previous studies confirmed the regenerative capacity of the mammalian neonatal heart. We recently found that adult heart tissue-derived EVs can protect the heart from myocardial ischemia-reperfusion (I/R). However, the role of EVs from neonatal heart tissue in cardiac healing post-ischemia remains unclear. In the present study, we revealed that intramyocardial administration of neonatal cardiac tissue-derived EVs (ncEVs) alleviated cardiac inflammation, mitigated reperfusion injury, and improved cardiac function in murine I/R models. In vitro, ncEVs inhibited M1 polarization of macrophages induced by LPS while up-regulated their phagocytic function via the miR-133a-3p-Ash1l signaling pathway. Moreover, the administration of ncEVs contributed to cardiac angiogenesis and improved cardiac function in murine myocardial infarction models. Collectively, these results suggested that neonatal heart-derived EVs can regulate the function of macrophages and contribute to cardiac regeneration and function recovery in murine cardiac ischemic models. Therefore, the derivatives in neonatal heart tissue-derived EVs might serve as a potential therapeutic strategy in ischemic diseases.

Isoflurane pretreatment protects against myocardial ischemia/reperfusion injury via mediating lncRNA CASC15/miR-542-3p axis

The protective effect of isoflurane on cardiomyocyte ischemia/reperfusion injury (I/RI) was explored in hypoxia and reoxygenation (H/R) induced cardiomyocyte injury model. In terms of mechanism, the participation of long non-coding RNA CASC15/microR-542-3p axis was further discussed. H9c2 cells received H/R treatment to mimic myocardial I/RI. RT-qPCR was performed to quantify mRNA levels. Cell viability and apoptosis were evaluated after isoflurane pretreatment and cell transfection. ELISA was performed to measure the concentrations of inflammatory/oxidative stress-related cytokines (TNF-α, IL-6, MDA, SOD). The target relationship between CASC12 and miR-542-3p was determined via dual-luciferase reporter assay. Isoflurane pretreatment alleviated H/R-induced cell viability suppression and cell apoptosis promotion, which was accompanied by CASC15 downregulation. CASC15 overexpression abolished the influence of isoflurane on cardiomyocytes' viability and apoptosis. H/R-induced excessive release of TNF-α and IL-6 was hold down by isoflurane, which was re-activated after CASC15 overexpression. The concentration changes of both MDA and SOD by isoflurane were reversed by CASC15 overexpression. CASC15 functioned as miR-542-3p sponger, and miR-542-3p overexpression attenuated the effect of isoflurane and CASC15 on H/R-induced cardiac I/RI. Isoflurane pretreatment was beneficial for the alleviation of cardiac I/RI by inhibiting oxidative stress and myocardial inflammatory response. CASC15/miR-542-3p axis was required for isoflurane to exhibit its protective activity against cardiac I/RI.